Some basic questions

rcrit

I'm starting my second heating season with steam and have what are probably some basic questions. I have Dan's books but haven't read them in a few months. I'm not as afraid of my boiler as I was when I bought this place but the knuckehead to expert is quite high so I try to avoid doing things myself that might leave me without heat and at the mercy of whoever I can manage to get on the phone. Steamhead is the only person I'll let touch my boiler at this point and he is, of course, in high demand right now.



I have a 1-pipe undersized boiler right now. My EDR is 87000 and the boiler is 78000. That's where we're starting. I hope to limp through another winter with this boiler and replace it next summer. My plan for this winter is to put some very stingy vents on my 3rd floor and/or shut them off completely to bring things more into line (the combination of those two rads is something like 13k EDR). I've found that if I shut them off then radiators downstairs don't warm up well (venting bad somewhere, I suppose). I'm a computer guy and have enough electronics to make up the difference :-)



As a result of my underwhelming boiler none of my radiators warm all the way across. This is fine, once it gets really cold they do end up all heating up half way or so, so at least we have heat. I have variable vents in key places that I use to try to keep things balanced.



Ok, so now you know my system, here are some questions:



This the summer over the course of a few days I'd fill the boiler, bring it to a boiler, then flush the heck out of it through the low-water cut-off trying to clean the muck out. Thinking I had done a fine job I filled it again, boiled it off then shut it down. This morning I flushed it for the first time and all kinds of goop came out. I spent a good hour or so filling and flushing and never really got it to run clear-ish.



So question #1 is: I shouldn't add cold water to the boiler, but I have to refill it after I flush water out. What I do now is turn the valve just a hair so water trickles in. It requires patience but it does seem to work. Am I crazy for doing this? Doesn't an auto-fill do the same thing?



I also see quite a bit of surging in the glass, once even filling it entirely. Question #2: Is this bad, just a symptom of a dirty boiler?



Question #3: how hot should my main vents feel? I have two mains, one with a Hoffman #75 and one with a Gorton #2. The Hoffman is untouchable, the Gorton not so much. Its warm, for sure, but not as hot as the Hoffman. Is this a sign that it isn't working as it should?



As I said, the heat generally works fine once it gets really cold and it fires up a lot but on those high 50's morning the house is cold. The boiler runs but seemingly not enough to fill all the radiators. Question #4: Is the obvious answer simply to bump up the thermostat a bit? Or is something else going on?



And finally. I spent a fair bit tonight just watching and listening to the boiler. I cranked the thermostat up just 5 degrees or so and grabbed a chair. It was a relatively cold start but boy it ran forever. The Hoffman has a nice "clink" to it so I know when it opens and closes, I find this very comforting. I heard it "clink", I assume closed, then nothing. I must have watched things for 10 minutes and boiler ran the entire time and the Hoffman never re-opened. Does this mean I was creating continuous steam somehow? The radiators all warmed up nicely, so I can't complain too much I suppose, I just found it disconcerting.



Another odd thing is when I would shut off the incoming water during my fill and purging I'd hear almost a sucking sound in the water pipe on the boiler side, like it was trying to suck out whatever water remained in the line. It would do this a few times, then settle down a little, then fade out altogether each time I'd turn the water on and off a tad.

BobC

Basics

EDR refers to the square feet of radiation that the boiler feeds. Steam boilers are rated both in BTU's and Square Feet of Steam, find out how many sq ft of steam your boiler is rated for and compare that to the total of all the radiators.



The boiler should be able to supply more square feet of steam than the connected load (15-30% depending on the pickup factor). "The Lost Art of Steam Heating" has some charts that will let you figure how many square feet (EDR) your radiators have. As an example I have 3 column radiators that are 38" high, according to that chart each section is 5 sq ft. The living room radiator has eight sections so 8 x 5 = 40 sq ft for that radiator.



Steam can only heat the radiators if all the air in the system gets out of it's way, steam will not go where air is. That main vent that is just getting warm has probably failed shut. Radiators on that main will take forever to heat up. You really should figure out the volume of the main and select a main air valve that will vent that main in about 2 minutes. "Greening Steam" and the "Balancing Steam Systems" ebook both explain this process. For now just get another Gorton #2 and replace that bad vent, if you end up needing more venting you can add more later.



You mention that shutting off the two radiators on the 3rd floor causes some radiators not to heat as well. that is probably because the mains air is trying to vent out of the individual radiators and when you shut two of them off the venting slows down a lot. Once you replace that vent that situation should change.



Once you get the mains so they fill with steam all the way in a couple of minutes you can see how the radiators are doing, you may find some bad radiator vents on them. i use the Hoffman 1A adjustable vents (pexsupply.com sells them at a good price especially if you buy a six pack), I have tried the cheap Chinese adjustable air valves but I don't really trust them.





Now as to the dirty boiler water, any time you add fresh water to the boiler you have to boil all the oxygen out of the water or it will attack the cast iron. If that boiler has been poorly maintained in the past it will take a lot to get cleaned out. The LWCO port is pretty high up. You should try flushing the boiler from a mud leg (down at the bottom of the boiler) to get more crud out and it might take power washing to get it really clean. For the moment just try and flush as much crap out of the bottom of the boiler as you can.



What pressure is the boiler running at? It should be below 2 PSI and preferably lower. The gauge on your boiler is probably 0-30PSI and seeing 2 PSI is not easy, you might want to add an outboard 3 PSI gauge so you know what the pressure is. If the gauge doesn't move at all it may have failed and then you have no idea what pressure the boiler is running at. The higher the pressure the less efficient the system will be, keep the pressure low.



Once the boiler is relatively clean, the venting straightened out, and the pressure set where it belongs the sight glass might calm down. If not the near boiler piping has to be examined. Post some pictures of the boiler and the near boiler piping so we can see what your dealing with.



I'm just a homeowner but I've lived with steam heat all my life, until I bought and read Dan's books most of what I did was monkey see - monkey do. Those books contain a lot of information, with that knowledge you will understand more than a lot of the people who work on them do because too many of them were never really trained on steam.



good luck,



Bob

rcrit

answers

The 87000/78000 figures are in BTUs. My steam guys were amazing to run into such a grossly undersized boiler. I know I need a new, properly sized boiler, I'm just trying to limp through another heating season by making it work as best as I can. I insulated most of the mains last fall and that made a good difference.



I pulled off the Gorton #2 this weekend and it blows quite clear. Perhaps I simply need more venting.  On my radiators I have a mix of Hoffman 1As and Vent-Rite fixed vents. When its really cold out and the furnace runs more often then things heat up in a relatively balanced way. Its just on these semi-chilly mornings when it doesn't heat well. I pulled all of the vents off this weekend and all where clear and a bonus, no water poured out!



My pressuretrol is set at its lowest setting and yeah, my 0-30 gauge is pretty useless.



Unfortunately there is no mud leg on this boiler that I can find. The closest thing to it is on the wet return. I'll keep blowing it down every couple of days for now, it is certainly clearer now.



The near-boiler piping is ok, it's just copper :-(

BobC

More information needed

Your boiler is slightly undersized but the fact it heats fine during really cold weather tells me that is not the problem. You might want to dial down the venting in the room with the thermostat to get the boiler to run a bit longer and see if that helps things. You also said the third floor gets too hot, have you dialed down the venting on them yet?



You said the Gorton #2 (which never really gets hot on light heating days) appears to be clear and that all is well on really cold days when the boiler has to run longer. How long is each main and are they the same diameter? How many radiators feed off each main? Also can you tell us which radiators feed off what main and how they heat up in relation to each other?



It seems the steam prefers to go towards the Hoffman main rather than the one with the Gorton on it. The Gorton #2 has about 2-1/2 times the venting capacity of the Hoffman 75 so something is up unless the main with the Gorton is much much longer than the Hoffman's main is. Is all the piping pitched back towards the boiler? Use a level, don't just depend on your eyes, If you have water pooling in the pipe that can't find it's way back to the boiler that can cause problems.



I don't think you mentioned anything about your header and hartford loop, if they are not set up properly, the boiler is not going to work as good as it should. Dan's books have plenty of illustrations that show how they are supposed to be set up. Also some pictures of the boiler, near boiler piping, and the mains (and main vents) would make it easier for us to visualize your system.



Bob

rcrit

info

It heated well enough for me last winter, which was a cold one in Maryland for sure. My wife might not agree :-)



My thermostat is junk and misplaced, which may be part of my problems. I'll be replacing it next month hopefully. It sits only about 24" off the floor about 3ft from a radiator, not ideal. I have a thermometer in another room that I use to guess how high to set the thermostat and it works fairly well (by my low standards). The room with the radiator opens to the entry and a small bath both unheated, so I figure things balance out right now. Given this though you'd think I'd be screaming about being hot with huge bills, not that it doesn't heat well enough.



The mains are both 2". The shorter main is 25' and serves 4 radiators. It has a Hoffman 75 at the wet return. The longer main has a T in it. The length to the T is 16'. The shorter side (8') serves 3 radiators and the longer side (14') serves 4. The longer side has the wet return and the Gorton on it.



For a point of reference, right now it is 47F outside and my thermostat is set at ~72. The inside temp is 72 according to my trusty thermometer. The first floor radiators (4 of them) are all heating 1 or 2 sections, on the second floor radiators (5 of them) 3 are stone cold and 2 are 1 section warm, not hot. The third floor has a radiator with no vent (to encourage the steam to rise) and is 5 of 8 sections hot. The other radiator on the 3rd floor is also cold.



The boiler has been cycling ok for at least 90 minutes. I know because I blew it down a few times over that period.



While in the basement I listened to the Gorton for a while and I could hear it puffing air, so it is definitely working to some extent.



I've attached a few pictures show my lovely copper header and the boiler model. The non-copper mains are all insulated with a mix of pipe insulation and R-13 I wrapped around them. Putting R-13 anywhere near an exhaust makes me nervous which is why I haven't insulated the header itself.

JStar

Pictures.

You've just found the cause of your surging. That near boiler piping is very far from correct. The sad part is that it seems to be working...sort of.



It's time to open up those books, and get an idea of what a near boiler set-up should look like. Then you'll have to decide if it's worth the investment to repipe. You'd have to remove any steam lines in copper and start over from there.

Dave in QCA

Warm Gorton #2 is normal

I have both Hoffman 75 and Gorton #2 vents on my system.  My hoffman make that clink sound when they close, and if you touch it, you're likely to burn your fingers!  On the other hand, the Gorton #2 vents very well, but closes as a bit of steam inters it.  It is quite warm, but not hot.  The pipe leading to it, is has as steam though.  After the system runs for an extended amount of time, the Gorton continues to get hotter.   This is normal, becuase the air has been removed from the main.

Dave in QCA

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Dave in QCA

My stab at answering your questions...

Surging in your site glass is probably caused by 2 things.  It can certainly be caused by the dirty boiler.  You need to find where the mud leg drain is supposed to be and install one at that  location.  Make sure it is a valve that when open, has a passageway that is the same size as a straight piece of pipe of the same size.  Ball valves work nice for this.  In looking at your boiler manual, I see that the return piping is the only location for this.  Check the diagram and see if your's is in the same location. The probable principle cause of your surging is from the improper near boiler piping.  Fortunately, it was done in copper and that will make it easy to remove.  The copper piping is a blessing in disguise.

In the beginning part of the boiler cycle, as it begins to produce steam, the steam should run out to the main vents fairly quickly.  Ideally, once the steam begins to run out, the mains should be completely vented in 2 minutes.  Also, during this time, it is ideal that little or no steam enters the radiators.   Once the main is fully vented, steam should begin entering all of the radiators, ideally about the same time.   If you have some radiators that are heating faster than others, they are being vented to fast.  Radiators that are vented too fast can hog all of the steam and will not let it go to radiators down the line until they are fully heated.   The old adage is "vent your mains fast and your radiators slow." 

I helped a friend who had a few years prior had a new boiler installed.  In the process, the contractor installed all new Hoffman 1A vents, and had them all in the wide open setting.   The radiators would heat as if they were in a row, the last radiator would not get any steam untill all of the others were completely hot.  Turning all of the near radiator vents down to low settings (reducing the venting) corrected the problem.

If I am picking up on your description of how your boiler operates, I think you have said that if the boiler operates for a long period of time, all of the radiators will get hot.  If that is so, your boiler probably is actually sufficiently sized.  Remember that your IBR steam output has an extra 34% in there for piping losses and pickup.  If your actually piping losses are less, than the boiler may actually be adequate for your system.

In mild weather cycles, it is normal for the radiators to partially heat.  That is what they are supposed to do.  However, you need to get the radiator venting balanced so that every radiator gets a little steam anytime the boiler cycles.  Your thermostat placement is obviously wrong and may be contributing to shorter cycles than would be normal, especially if the radiator within 3 feet of the thermostat is one that gets steam.  The thermostat should be on an interior wall, and on the opposite side of the room as the nearest radiator, if possible.

Regarding the hoffman #75, it closes when the steam gets to it, and thus the air is out of the main and it has done its job.  As long as the boiler continues to fire, there is steam at that vent.  There is no way for new air to arrive at that point unless the boiler fire shuts off, and the system sucks in air to replace the steam that quickly condenses.  It is normal for it to remain closed during the boiler operation.  The hiss at the end of the firing cycle is not venting air out, but rather air venting back into the system.

BobC

venting

Dave's comments below are all very good and should be followed.



In you original post you said the main with the Hoffman 75 and all of it's radiators heated fine but the one with the Gorton #2 didn't seem to heat up as well. Does the pipe below the Gorton vent get steam hot? If I understand your description this main runs out 16' and then T's off - the 14' side has the wet return and Gorton vent while the 8' side has no venting. Have you checked the slope of this short main to make sure it slopes towards the return? Without a vent on the short side of the main the steam is not going to go there untill everything else is full. If the radiators on this short side of the T are not heating I would find a way to add a vent to this main. If that isn't easily done then those radiators should have larger vents on them because they have to vent the main as well as the radiators. It seems the T shaped main just needs more venting assuming all the piping is sloped correctly.



Also that third floor radiator without a vent in it will steal the steam from everything else on that main. Try to make a chart that shows how long it takes the boiler riser pipe hot and then how long it takes the end of the short main and both ends of the T main to get hot. Then determine which radiators the mains feed and which of those are not heating correctly. This should be done after putting an air vent back in that 3rd floor radiator.



Bob

Steamhead

We'll look at these things

when we come to install the radiator in the bathroom you wanted.



The gunk in the system has likely been there for years, but the improved steam circulation is washing it out and sending it back toward the boiler. Keep flushing, you'll get it eventually. And you definitely do not want to refill a hot boiler with cold water. Let it cool down for a couple hours first.



Meantime, take a look at some of our Smith G-8 installs as posted recently. That kind of piping is what you should have.

mel rowe

Boiler capacity

Homeowner with one pipe steam system here.  I have used Dan's book and the advice of many Wallies to totally revamp my own system and solve many problems.  I just wanted to throw in my opinion regarding boiler replacement.  I've been surprised by several of my friends' whose steam boiler calculated out as being undersized, only to find out that they had no problems achieving a comfortable house in the coldest weather.   



If your house insulation has been improved through the years you may find that the your boiler does not seriously underperform as the formula predicts.  If you clean the system really well, make sure the  mains are vented adequately,  balance the rad venting so that the rads heat  up at about the same time, and make sure the thermostat is in a location that is last to reach set temperature, then you only need to see if the system can maintain the desired temperature on a very cold (design) day, while running essentially 100% of the time.   If so, can a new boiler do any better than that?



I found this article, written by one of the Pros on this site, to be very valuable reading material on this whole subject.



http://www.heatinghelp.com/article/11/Hot-Tech-Tips/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell

rcrit

insulation? What's that? (long)

I'm not entirely sure how well-insulated my house is, to be honest. I've only been in it for a year but in its 90-year history its seen some major changes. From the 30's to the 50's it served as the telephone switching station for our community. The sister of my neighbor remembers playing with leftover telephone equipment in the late 60's (unfortunately all that is long gone).



It is apparent that some of the walls have been replaced, I can only assume that some kind of insulation was added at that time. Given that the ceiling/roof in the 3rd floor space has R-7 in it I'm not very optimistic.



I do suspect that many of my problems are related to venting. I just finished Greening Steam and what really caught my eye was the bit on adding main vents to the top of a long vertical runs. That is essentially what I've done to get steam up to my 2nd floor by removing the vents on my 3rd floor rads. I get the air out and up. Granted this is not ideal. I've replaced the vents which has the nice side-effect of actually keeping my water level more stable.



What I've done for now is install a VentRite-11 on the rad next to the thermostat. This is a fairly stingy vent and things worked somewhat ok until our latest hot-spell (mid 70's) so I haven't had much time to tweak things.



But still, on some of those 40 degree nights, even with my Hoffman 1A's caps removed, some radiators wouldn't heat at all. Ever, or at least until I started popped off vents. The mains seem to be venting fine and the math says that the vents I have and the lengths of the mains it should be adequate.



My water still bounces like crazy, I'm going to assume its dirty as hell. Dumping via the LWCO has cleared things up significantly. I'm a little afraid to drain anything through the wet return (no mud leg). The valve looks like it hasn't been used in decades.



I also did something rather dumb with my pressuretrol. I was showing my wife the basics of steam, trying to get her on board, and was describing low pressure with my neat  counterclockwise screwdriver. I managed to completely unscrew the set screw. I was able to re-insert it and haven't noticed anything too evil, though my bedroom vent seems quite loud to me. I wonder if I've screwed up my pressuretrol so pressure is too high. And yes, I know, pick up a low pressure gauge.



I still don't get the whole refilling the boiler thing. I get that adding cold water to a hot boiler is going to crack it. But what is a homeowner to do, shut down the boiler in the middle of winter for a couple of hours every week to blow it down? How is my turning the valve a little any different than a autofeed adding water?



Frank and Gordon will be out to save me in the next couple of weeks, I'm just trying to make sure I ask all the right questions when they get here.

BobC

Adding water to the boiler

I look at my boiler everyday during the heating season because i have an elapsed time meter on it so I can track the number of hours it runs. I keep a log right besides the boiler so I can see how any tweaks I've tried work out and what the daily consumption of oil is.



I try to add water at the start of a steaming cycle so I'm not dumping cold water into a steaming hot boiler. This also ensures any oxygen in the water is driven off. If I do find the level too low, after returning from a vacation, I'll just crack the valve and let the water in slowly so I don't shock the cast iron if the boiler is operating and I operate the boiler long enough to drive off any oxygen.



That technique has worked for 14 years.



Let us know what the boys discover when they come out to look at your system.



Bob

mel rowe

40 degree nights

On those 40 degree nights, was the system running 100% of the time, or was it still shutting off on the stat, before some rads were heating all the way across?  If shutting off on the stat, doesn't that indicate you still have some system venting/balance problems, as opposed to confirming a boiler capacity problem at this point?  Those long vertical risers to the 3rd floor are like having to vent mini-mains.

rcrit

thermostat

No, the system cycled on an off. No radiator heated all the way across, but it also wasn't frigid cold either so not unexpected (though mine have NEVER heated all the way across unless I crank the thermostat way up).



My thermostat sits a few feet from a radiator and a few feet from unheated space so it is very unclear what relationship the value I set it to has to the actual temperature. I did crank it up a bit, to 75 on the dial, and the second floor rads heated a little. When it was set to 72 only the first floor got steam, presumably because the boiler never ran long enough to heat the risers to the second floor.

mel rowe

Boiler capacity

Well, obviously you are going to find out a lot when the pros visit you

in the next few weeks.  In the interim, these are just some thoughts

based on my own (homeowner) type experience plus what I've learned from

lurking on the Wall, doing my own work and also some friends systems as well.   









I expect that your thermostat setting bears no relationship to temps in

other areas.  If you have a decent thermometer, it might be good to

record some temps in other areas of the house at the time when system

shuts off on the stat.   From what you've said it sounds pretty clear

that you will need to do a lot of venting/balancing in order to get

steam up to the top floor before the stat shuts it down.  Even if you

increased capacity of boiler, I don't think your current setup would get

heat up to the 3rd floor before the stat shuts down.  By the way, have

you tried using the VariValve type of vents on the upper floor

rads.  These vents are adjustable and have a large venting capacity that

might just do the job on those risers to the 3rd

floor, which due to their length are basically "mini-mains".   With this

type of venting capacity on the upper floors, it might prevent the rads

near the stat from heating up too quickly and shutting the system down.











Based on my limited experience on my system and also working on some

friends' systems, and in view of today's house conditions, I previously

had

questions about the industry practice for calculating boiler capacity. 

It was

very interesting when I ran across the article by BoilerPro, for which I

gave you a link.  In that article he also raised the possibility that

the industry practice of calculating attached load plus 30% as being too

high compared to heat loss with today's house conditions.











Since it appears that your boiler is fairly new, and they are not cheap,

I would think that you want to be very sure of the need to replace.  

If you can get the system adequately vented and balanced to properly

distribute heat, then on a design day (coldest expected temperature), if

the system can achieve desired temps while running at 100% of the time or less, then why replace?

rcrit

size vents to radiator

The article you mention makes sense if your radiators are placed in a reasonable way. Mine are not. Its almost as if some devious owner wanted to make life extra difficult for me.



The smallest bedroom, maybe 9x10, has an 8-section radiator in it (9600 EDR by my calculations). The one in my bedroom, about 14x14, is a 6-section (7200 EDR). Even my bathroom has a larger radiator than my bedroom.



This makes my venting choices very interesting. I have Hoffman 1A's on all the bedroom rads and on those just slightly cold days I tend to take the caps off altogether and sooner or later things warm up (just usually not at bed time). Since it has been getting progressively colder, 40's in the nights now, I've had to turn down most of the vents to 3 or 4. That big monster is set at 2 now.



It is quite a bit of playing weatherman and running around setting vents at what I think is the appropriate level for the night. I'm thinking a bunch of TRV's would make this much easier, I'm just a bit nervous about making a poor choice since they are rather expensive.



So a codicil to BoilerPro's excellent article might be: if your radiators placement was decided by knuckleheads, all bets are off.

jpf321

double check your figures ..

most residential boilers are rated below 1000 EDR total, you are coming up with 9600 for a single rad, something is askew

jpf321

why don't you consider ..

swapping them around sizing rads to room sizes ..



it's quite possible that once long ago a painter took them all out and put them in the living room and then when he was done painting the walls, he put them back all mixed up, or decided to put the largest one in the closest room because it was heaviest, and the smallest in the furthest room because it was relatively the lightest. because I can almost garuntee you that the Dead Man (*bows head*) that placed the initial equipment order for the house, knew which room got which rads. 

Dave in QCA

EDR is measured in square feet

It looks like you are probably calculating the total BTU per radiator, not EDR, which is given in square feet.  If your boiler was perfectly sized, the EDR of all the radiators added together would equal the EDR rating of your boiler, which is also given in square feet.  That EDR number on your boiler has already accounted for the extra 34% for piping losses and pickup.  So, if it is small, and you have less than the normal piping losses, you still might be OK.

You seem to be stuck on the fact that your radiators don't heat all of the way across.  At the same time, you report that the boiler is not running all of the time.  I am sure that you must realize that the boiler does not make steam when it is not running.  So, this still does not give conclusive evidence that your boiler is undersized, although it may be.

Is the thermostat satisfied?  That means, does the room temperature where your thermostat is come up to the set point? If the answer is yes, then you obviously have a balancing problem.  Is this thermostat in a proper location?   If this room is heating OK and others are not, I would suggest changing the vent settings on your radiators.  Opening the vents on the cold radiators will not make them warmer if the other radiators are taking all of the steam.  You have to close the vents partially on your warm radiators to get some of the steam to into the cold radiators .  

I would suggest as starting point, since your system is probably shy on steam capacity,  reset all of your radiator steam vents to the smallest number (just barely open) and see what happens on a steam cycle.  Remember, you want to get a little steam to every radiaor.  The radiators are not going to heat all the way accross, since your boiler is not running for a prolonged period of time.  In mild weather, boiler cycles of less that 30 mins after the boiler has started to steam, the radiators are NOT supposed to get hot all the way accross.  Hot all the way across is what happens when the boiler fires continuously for 45 mins to an hour, and it is below 0 outside.

Don't go out and buy thermostatic radiator vents thinking that they are going to balance your system for you.  They will not.

rcrit

bad math

Ah yes, I multiplied those out by to BTUs. The EDRs in question are 40 in the small room and 30 in the master. You could be right about the painters. The house sat vacant for a few years. Who knows, the seller could have hooked them up at random as far as I know. Nothing surprises me about this house anymore.



I'm not at all hung on up heating all the way across, I totally get that. Not heating up at all is what bothers me. The way I have it balanced right now more venting by floor. The first floor is almost all VentRite #11 which according to Greening Steam are rather stingy vents.. The second floor are almost all Hoffman 1A's set at 4 or higher with the exception of that big monster which is set at 2. The third floor has a Hoffman 1A with the cap removed altogether (the other I've turned off for now by turning the vent upside down).



The experience I get now is that on mild days the first floor rads heat up, maybe 2 sections. We're comfortable. The second floor (and third) floor doesn't heat at all. Even if I open all the 1A's up to 6 they get no steam. Heck, even if I take off the 3rd floor vent altogether that line doesn't warm up.



On colder days when the boiler is running more often the first floor heats comfortably and the second floor, presumably because of its more generous venting, gets quite warm. This I'm sure is partly due to crappy placement of the thermostat, caught between a hot and a cold place.  So it probably runs more than it needs to, overheating the 2nd floor.



Speaking of which, is there a convention on height of a thermostat? My old house had it at around 5ft, this one is maybe 2ft up from the floor.



I say the boiler is undersized because Steamhead says the boiler is undersized. He measured, and I confirmed, a radiator EDR of 87000 and the boiler is rated at 78000. I'm guessing the difference is worse than 11k because the 78000 includes the pickup factor and the radiator EDR does not, right?



I'm willing to try certain things, but not things that would leave me without heat. I've already had a couple of knuckleheads look at this boiler, one of whom wanted to crack open a pipe to fix a "blockage". Sagging pipes will do that. One of the things I can do is play with the balancing so when I get the good guys out here and they ask "Did you try..." I can provide a reasonable answer. I'm just trying to figure things out.



I did manage to clear up the water in the sight glass considerably by blowing it down every other day. I found what I think is the skim port but it is blocked by the LWCO, so that's out for now. I'm not brave enough to try the valve on the return to try to drain things.



On the bright side the fireplace that the home inspector and 2 of 3 chimney sweeps said wouldn't draft properly works great :-) And you guessed it, the fireplace is in the same room as the thermostat...

jpf321

are you willing....

1st .. rearrange the rads base on room size/fenestration sq ft.

2nd ..get Gerry Gills venting and balancing download book available from Dan's shop. (and my spreadsheet to help you with the math available in my signature, but get his book first)

3rd .. be prepared to throw out all your current vents and purchase new ones (my personal preference is Gorton) based on your new balancing calculations. or at least know where the ones you have should be set.



if a rad is undersized to a room, the room simply won't get warm enough no matter how you vent it. an oversized rad, on the other hand, can be throttled by venting.



if you properly size the rads to room and properly balance the system, all rads and rooms, in theory, heat equally so thermostat placement should be irrelevant. the fact that it is lower to the floor means that it probably calls for heat a little LONGER than if it was higher up .. cold air drops, heat rises. that could be corrected by adjusting the t-stat set point (perhaps the air is 1degF cooler at 2ft rather than at 5ft.)



we shouldn't spin your balancing wheels until the rad sizes match the room sizes. You'll go crazy. think of it as a glass of water with ice cubes .. you can't make a single ice cube (undersized rad) cool the water any better .. but if you add a full scoop of ice (oversized rad) .. you can always remove ice cubes to where you desire the cooling effect to be ... you can always turn down an air conditioner (although in some cases you shouldn't) but you can't ask it for more than it's able to give.

Mike Kusiak_2

Thermostat location?

Mounting a thermostat 2 feet off the floor is quite unusual. Typical placement would be at eye level or around 5 feet from the floor. At 2 feet it will not accurately reflect room temperature, although the effect would be to measure the cooler air near the floor, making the boiler run longer.



The pickup factor reflected in the steam BTU rating of your boiler actually makes the boiler less undersized than you think. The pickup factor of 1.33 is calculated in this rating. The actual output the boiler is capable of is 1.33 x 78000 = 103740 BTU, which is still larger then the 87000 BTU the radiation is rated for. Its just that your pickup factor is less than the usual 1.33, and calculates out to 103740 / 87000 or about 1.20 . The boiler capacity is still more than adequate to fill all the radiators with steam, it just may take a bit longer to heat up all the piping and get steam to all the radiators.

Dave in QCA

Bad Math is better than no math at all... maybe...

OK, I am with you now.  Your radiators add up to 87,000 BTU when fully heated.  87,000 BTU divided by 240 BTU/Sq Ft equals an EDR 362.5 sq ft.  That is your EDR.  It is always in sq ft. 

Your boiler rating plate shows an EDR of 325 sq ft, and a Net BTU rating of 78,000.   Both of those numbers already have the 33.3% for piping and pickup accounted for.  So, you've got 37.5 sq ft more EDR connected to the boiler than what it is rated for.  If your piping is less than average and there is good insulation on the pipes, and you can live with long firing cycles, you might be able to make this thing work if it is well balanced.  That is the problem (as you know).

While you're trying to solve the most obvious problems, you might as well get that thermostat located to a reasonable location 5' above the floor.  My recollection is that you said it was close to a radiator, one which actually does get hot.  That will cause the thermostat to sense a warmer temperature than what is actually the room temp, and shut the boiler off.  If the steam hasn't had a chance to get to the farthest radiators, then the whole cycle repeates itself, and those far radiators will never get any steam.  No matter what else you find, you will still need a thermostat in a proper location, set for 1 cycle per hour.  Bad location, either near a radiator or next to a drafty window, and 2-6 cycles per hour will never work for you, even if you had a boiler twice the size of what you have now.

The next thing, in the process of elimination...  

It sounds like you have one, perhaps more radiators that have never ever gotten warm.  Not even one little bit.  If that is the case, I would try to do some tests to confirm that the piping to that/those radiators if actually connected to the boiler system.  I would turn off every radiator in your house except for those that have never ever gotten warm.  Then crank up the thermostat 10 degrees and watch what happens.  If those radiators heat up, then you know they are connected, if not, then you know you have a piping problem.  At some point, the boiler should shut itself down on the pressurestat.

If the piping starts harmmering as the steam gets to those far radiators, then you know you have a low spot that will have to be corrected.

If they just heat up fine, with no issues, then it is a matter of balancing.  As I said before, I would take all of your adjustible vents and put them on the very lowest setting possible.   Ideally, steam should begin to flow into the first section of every radiator in the house at the same time.  In your situation, you can't speed up the slow radiators by increasing the venting.  You have to reduce the venting on the radiators that get steam first.  Reduce it alot.

You should not have to run around changing venting for the time of day.

Also, if you suspect that radiators may have been moved around, that is certainly possible.  Also, it's possible that one or more started to leak and were replaced with whatever they could find, even if the replacement was not correct.  If you have wood floors, there are usually telltale signs left where the original radiator feet were located.  See what you can find.

You are going to get this thing resolved, and hopefully, you won't have to spring for a new boiler.  You are wise to try to collect as much information and data as is possible before the pros show up to help you out.

Regards,

Dave

rcrit

thermostat moved

Since it seemed like a lot of my problems were related to the odd placement of my thermostat I went ahead and moved it last night. It is now at 5' and basically in the center of the first floor, away from any drafts, direct sunlight and radiators.



It seems to be already making a difference. The second floor wasn't as overheated this morning as it had been the last couple of days. I still have some balancing to do. I'm going to try the "vent based on size" method as best I can with the vents I have. I have quite a few Hoffman 1A's but only a few of the caps and screws. I'm guessing the previous owner took them off trying to get steam everywhere and many were lost or damaged. I had one screw that was missing all the legs so it was basically disabling the vent altogether :-)



Thanks for all the advice, I'll update this post again in a couple of days.

jpf321

so no...

rearranging of rad size based on room size is in the plans?

rcrit

moving rads

I'll be sure to ask my pros about it. They had a few ideas on it last year but at that point the focus was getting everythingl leveled and working at all. It is definitely not something I'm going to take on myself, I almost rode a cast iron sink down the stairs already (a great story, really), and that only weighed about 90lbs.



I think what I need to do is inventory what I've got (I have that by EDR, I probably want to add in height too) and then do a heat/loss on the rooms, etc, and figure out what should go where and take it from there.



One rad I'm going back and forth on is the one in my office. I work from home and my office faces due South so I get full sun all day long. It was really fun in the summer when I discovered the ceiling and walls had R-7 in them. I installed R-19 and R-15 and that made things a lot nicer. I'm wondering if my office is tight enough now that with the heat coming from my computers will be enough. Last winter, before I insulated, I ended up with a window open almost every sunny day and the vent set at 2 or 3.



This is a long way to ask, am I going to screw up any balancing I do if I turn the vent upright every now and then to warm things up on those especially cold days?

Dave in QCA

Sounds like you have just reduced your system EDR

Well, if your office was warm enough you had to open the windows last year, and now you have added insulation, it stands to reason that you sure won't need much radiation there now.  Your boiler is 37.5 sq ft short of matching your total system, so if the radiator in your office is about that size, you have just balanced your system to your boiler.  This might be a great place for a TRV, or if you want to manage it manually, just turn that vent upside down except for the rare occaisions that you need a little heat.

As long as the vent on this radiator is balanced with the rest of the system and all of the rest of the radiators are balanced,  it will not put the rest of the system out of balance when you turn the radiator off.



No need to hurry into moving radiators around unless you determine that they really are incorrectly sized, and you have not done that yet.  You commented that the radiator in your bedroom is a little smaller than the radiator in a smaller room.  But, more importantly, if that smaller room is on a corner, and your bedroom is not, and if that small bedroom has equal or greater amount of windows than yours, if it is on a different floor that has unheated space above or below, and your bedroom does not... all of these things affect the heat loss of a given space, and size of room alone does not determine the size of the radiator needed.

I think you are on the right track.  Keep us posted

Dave in QCA

Another thing to check

I have seen boilers that wouldn't heat because for some reason they were firing way less than the rated firing rate.   To cover that possibility, you should have your boiler running, but no other gas burning appliance.  Don't worry about pilot lights, they don't burn enough to measure for this purpose.   Clock your meter and see how much gas you burn in a minute, multiply by 60 to get cubin feet per hour.  Multiply by 1000 to get BTU/HR.  Heat content of a cubic foot of gas varies somewhat, but for this purpose, 1000 is probably close enough.  

You should come up with a number that equals the INPUT BTU of your boiler.   If it is significantly lower, this could be another factor in your problems.