Old House with a fairly new system and not satisfied with performance

pjmilford

This is my first post. I live in NH and have an older home. I had a new boiler installed a year ago and I am frustrated that it takes at least 2-3 hours for my house to warm from 65 to 69 in the mornings. once the house gets up to 69, it seems to stay there. I replaced my 2 main vents about 2 or 3 years ago, but that seems to be part of the problem, I removed them and when I blow on them, they seems stuck, but that also seems odd, because they are not that old?. i tried to boil them in vinegar and water, but that did not seem to open them. the main vents are Gorton #2's and I used these to replace very old Vent-Rite 77's. my boiler is a US Boiler Megasteam Model MST-629. I have 3 zones, 2 are forced hot water and both of those zones seem to run fantastic, the main part of the house is the third zone and is mostly this old one pipe steam system. to use this morning as an example, my setback at night is 65, at 4:30 am it calls for 67 and then again at 6:00 it calls for 69 and stays there until 7:30 at night to 67 and back to 65 at 10:00 pm. I use honeywell RTHL221B thermostats in all 3 zones. Today, it took until about 8:20 am to get the house up to 69, so almost 4 hours. I have Dan's book "We Got Steam Heat" and I know that my system should be running much better than it is. I use almost 2000 gallons of oil a year and it is so frustrating knowing that so much of this is used unnecessarily. Please get me started on figuring what is wrong with my system, I really trusted my independent heating and plumbing contractor, but am now having my doubts.....

KC_Jones

It sounds like a venting problem, but it could be more than that. Could you post some pictures of the boiler and it's piping so we can have a look at that. Bad boiler piping can cause issues. If it is venting you need to determine how much venting is needed. Unless you have a relatively small system 1 Gorton #2 vent on each main probably isn't enough. You need to measure the length and size of each main and post that here and we could help you determine how much venting you need. Did your installer measure all your radiators and size the boiler according to that? Are the hot water zones running off the same boiler? How large are the hot water zones? It sounds like you have a lot going on. Post as much information as you can and we may be able to help you. Also if you are losing confidence in your contractor you could post your location and we may know someone good in your area.

Abracadabra

With 2 hot water zones running off the boiler, that may have a significant effect on how fast the boiler can raise steam if the boiler was not sized properly. On a steam system, setbacks are sometimes detrimental. Try a setback to 67 instead of 65 and see how that works for a while.

BobC

See how long it takes steam to get to the end of the main from the time the header is steam hot, if it's more than 5 minutes it points to a venting problem. As KC said give us some pictures of the boiler and the piping around it; the length of the steam main and the size of that main. Is the piping insulated?

Bob

pjmilford

I am having some trouble sending a picture, I will figure that out. in the meantime, I have 2 mains, one is approx 50' and the other is approx. 60'. The installer did not measure the radiators, the boiler he replaced was under a warranty and it was no longer made, so I believe they sent a suitable replacement. The contractor indicated that the replacement was a much better replacement for what I had. the 2 hot water zones are actually pretty small, one is 2 rooms a total of about 25 X 15 feet and the other is a kitchen,dining room area about the same size. My hot water also runs off of the boiler.......it feels like the boiler either does not run when the thermostat calls for heat in the morning, or when it does run, it shuts off because of pressure and then has trouble coming back on long enough to get the steam into the system. I live in Milford, NH. thank you

Jamie Hall

This kind of thing has to be approached rather gently -- and logically.

If you are trying to raise the temperature from a setback, you are asking for a lot of heat -- much more than you would be asking for at a constant temperature (which is why setbacks are a bit on the dubious side, in terms of saving energy).

The first question to ask, then, is just how much heat am I getting out of my boiler? This isn't that hard to figure out. Step 1 is -- does the boiler run all the time when it is trying to recover, or does it stop for part of the time? If it stops, why? Pressure or low water? If it runs all the time, then it may be that the boiler is simply not big enough to heat the house (I'll get back to that). If it stops on pressure, though, the first thing to do is to make sure the venting is adequate. If the venting is adequate, then compare the boiler's rated output (in square feet EDR) to the radiation in the building.

Then the next question is to compare the building radiation to the heat loss. While it is rare for a building to be under-radiated on steam systems, it's not unheard of if there have been extensive remodels which removed radiators, or changed them. So -- add up your radiators and do a heat loss calculation, and see how the two compare. Keep in mind that you need a good bit more radiation to recover from a setback than you do to hold a constant temperature.

So -- is your boiler shutting off on pressure? If so, is it late in a cycle -- say 45 minutes in -- or early? If it is late, then check your building radiation for adequacy. If it is early, then check your venting. If that is adequate, the boiler may be oversized. If it never shuts off at all and some radiators don't heat (or heat enough), check the boiler size against the radiation -- you may have a boiler which is too small.

If the boiler seems reasonably well matched to the radiation, then you need to figure out why the radiation is inadequate...

BobC

Those mains should each have at least 2 Gorton #2's on them and more would be better. You don't want to use oil to squeeze all that air out through the radiator vents - vent the mains fast and the radiators slowly. What kind of radiator vents are you using.

When you have time list all the radiators you have with the height, depth (# of columns), and width (# of sections), that should give us an idea of the EDR of all your radiators. The chart below will help with that. Also list the vent used on each radiator.

Bob

pjmilford

thank you for the chart, I will work on that right away. I can not imagine that the boiler is too small, my gut tells me if it is either too small or too big, I would think it was too big. It is the largest model of the 4 options for this new megasteam boiler. hope these pictures shed some light.....I am hoping it is a venting problem. I will get more details, but I have 11 radiators, most of them are like the one pictured, about 4' tall by 7 1/2" wide, varying amount of columns, but I would say 11 or 12 avg. I am using Heat-Timer Varivalve Quick Vents and none of them are more than a couple of years old and seem to work fine.

KC_Jones

The only thing that jumps out to me on the steam piping is the connection of the mains. Those mains should have come down full size into the header. The way it's piped there is a single 2" pipe feeding the whole house off of the 3" header. It honestly doesn't make any sense. Not sure if that could be contributing to chocking down the steam flow, but the velocity you could be getting there could be sucking some water out of the header causing wet steam. Those mains look like 2 1/2" possibly? If they are and are as long as you state you are certainly very short on main venting. I would also talk to your contractor about that piping. Other may have some opinion on that as well. It might not be a huge problem, but it definitely isn't helping.

pjmilford

Thank you KC, you are correct. 2" risers (which is what the manual calls for) feed into a 3" header, but from there it goes into a 2" pipe, which then feeds the two main 2 1/2" pipes that feed the house system. (I do remember the installer "missing" some connection that was not included and he was upset about that at the time. He called the wholesaler and they figured out a solution. I have a feeling that this may be the 2" pipe you are bringing to attention)
I also have figured my radiation to be 450 sq.ft. for a total BTUH Load of 108,000. The system also has 2 forced hot water zones with 52 lineal ft. of baseboard for a total of 31,200 BTU.

BobC

With 2-1/2" mains of that length i would start with 2ea Gorton #1's on each main and be ready to add an additional #2 to each main if the mains do not heat fast enough. The Varivalves are very aggressive and make it difficult to balance a steam system, what are they set to?

The two mains really should connect seperately to the header for best operation but I'd deal with the venting first.

Bob

KC_Jones

If those EDR calculations are correct the boiler is over sized. Even with those water zones there should have been enough capacity in the next size down to cover everything. I would suggest you have a 2 fold problem, one that 2" pipe and second venting. You obviously aren't short on capacity. I would also think about finding out how much that boiler can be downfired to get you closer to the load you have. Question, does the boiler cut out on pressure during a heat call? If it does the downfiring could help that. If I did my calculations correctly you are probably seeing around 65 ft/sec in that single 2" pipe which is very high (someone please check me on that).

Jamie Hall

It is possible, although a bit remote, that that connection is more of a problem than might appear: it goes from 3" down to 2" (area cut in half) then it goes back up to 2 x 2 1/2" -- area roughly tripled. Saturated steam does not like to be treated that way; that's why reduced port valves are a no-no. I wouldn't want to go out on a limb with a saw and say that that was a good part of the problem -- but I'd be very interested in just how fast those mains heated up downstream. This is not a venting consideration; strictly one of contraction and expansion and the thermodynamics of saturated steam.

Perhaps I should add that I have seen situations in which a reduced port valve on a steam main essentially stopped the steam dead in its tracks -- almost all of it condensed, right downstream from the valve. Interesting...

pjmilford

Thank you Bob C, you will see on my last post that I figured my total radiation. In the meantime, I just turned my thermostat p to 72, in order for me to measure the time it takes for the heat to travel to the main vent. The following is what has happened, and the source of my frustration....
11:42, elevated thermostat from 69 to 72, burner motor started for a few seconds, but did not ignite
11:51 burner started and fired for 9 minutes then shut off. in these 9 minutes, the header was too hot to touch and the 2 main lines got very hot, but the heat never got remotely close to the 2 main vents.
12:03 after shutting off for 3 minutes, the burner went on for about 45 seconds and went off again
12:11 burner motor went on fora bout 10 seconds, but did not ignite.
12:24 burner motor ran for 3 seconds, but did not ignite
12:39 It has now been 47 minutes, the main pipes are starting to cool off. the burner has not ignited since and the temperature in the room where thermostat is located has not gone up or down a single degree in this entire time.
I should also add that this is a new thermostat, but performing exactly like the one I replaced (wanted to eliminate thermostat as the issue), I also had the boiler cleaned and serviced last week.

BobC

Is that thermostat set up for steam? Most come out of the box set up for hot air (5 cycles an hour). Steam usually wants one cycle an hour and in some instances 2 cycles an hour.

Check the thermostat and get some more vents on those mains. You will then find out if you need the steam mains repiped so they connect to the mains separately.

Bob

pjmilford

You guys are great and for someone like me, that would love to LOVE my steam system because my home is an old victorian built in the the late 1800's, I have been living with years of frustration, knowing that it has been taking way too long to bring my house up to temperature and using way too much fuel for what I feel I really need. In Dan's book, he mentions that in a good steam set up, from the time the furnace starts to the time that you start to feel pretty comfortable, should be in the 20 minute range........I have never experienced anything remotely close to that. I has now been an hour an 10 minutes since I turned the thermostat up to 72 and the boiler has fired for a total of 9 minutes, with about 5 or 6 occurrences of the motor starting but not firing. it is still 69 and the temp has not budged 1 degree either way in this entire time.
Bob, my vents on the 3 radiators closest to the boiler and the thermostat are almost closed, in my upstairs rooms they are about half way and in my hallways (first second and third floors are an open hallway with a spiraling staircase, those are set at open all the way.

KC_Jones

Something is shutting that burner down for sure. It almost sounds like a problem with the burner itself since you say it is trying to light, but doesn't. I know next to nothing about oil burners so I can not comment on that. A typical shutdown for pressure or low water won't typically keep the burner off for that long and it typically won't stop the burner once it tries to start.

KC_Jones

You say you just had the boiler serviced. Did they set up the burner? Clean the boiler out (combustion side), do a full combustion analysis and give you the printout from the analyzer? From your description this sounds like an issue with the burner to me. It should fire and keep firing unless some control shuts it down. That would be either pressure, low water or the thermostat. Another possibility is something wrong in the control circuit with the hot water side of things. Again I am no expert on that so hopefully someone else will chime in.

pjmilford

Thank you, I just reset the thermostat for steam, I did not realize there were options on that set up. They did not leave me with anything when they were done with the cleaning, so I do not know if they did anything or everything with the burner. One of the reason they came is because I had a noise going on and asked them to check it out. When they came, the replace the water circulating pump beween the boiler and the water tank, they said a bearing was stuck and that was causing the noise. I asked them to do a cleaning and maintenance, which they came back and did the next day. I know the guy was here for a while and that he had the burner and door assembly off completely, as i saw him vaccumming the inside of the boiler, but I am not aware of anything else.
also, the kitchen just called for heat and the burner came on fine for sevreal minutes, shut down for a couple more and came back on, the kitchen went up a degree or two and the boiler shut down again, just like it is supposed to work. So I think this further points to a problem with only the steam zone? what should I tell the heating guy when I call him? I don't feel like paying another $150 minimum charge.......thanks.

pjmilford

Also, I thought I would post a picture of my pressuretrol, to see what that should be set at, if that might make a difference

Abracadabra

I see a cyclegard on there

I'm guessing that's what's shutting down the burner every so often.

KC_Jones

That doesn't explain what is going on. Over an hour and only 9 minutes of burner run time? There is definitely something going on with the controls, but that's just my opinion.

ttekushan_3

Good call, @Abracadabra

To that I suggest actually raising the system pressure a bit. The mercury pressuretrol has an advantage in being able to see if it shuts off on pressure and if it is actually tilting back into position when it should. Those can stick "off" at very low settings, also mercury switches must be level!

That 2" pipe feeding two 2.5" mains is a significant restriction so a setting of 3 psi MAIN and setting the DIFF closer to 2 is what I would try. After getting your main vents straightened out. Heck, even without main vents that boiler should be able to heat through radiator vents only, not that heat distribution and efficiency would be where it needs to be. I'm just saying you have several problems with additive deleterious effects.

I'll add another too. Make sure there's nothing in the HW loops in series with the steam thermostat. So:

1. Main vents.
2. Raise pressure to 3, diff 2
3. Make sure pressuretrol is level
4. Watch to see if there's anything strange going on, like the steam side is only working if one of the HW zones is also calling for heat (the more I think about it, the more likely this seems)
5. Lose the cyclegard.
6. Have that supply piping corrected eventually.

That's my take. FWIW.

BobC

I assume you have separate thermostats for the steam and hot water areas of the house. Does the system act any differently with the thermostat set for steam?

The cycleguard low water cutoff is going to shut that system down every 10 or 20 minutes to run a test. Most of us hate that control but until it dies your kind of stuck with it. After the test the boiler should restart and run till it satisfies the thermostat.

Bob

ChrisJ

ttekushan said:

Good call, @Abracadabra



To that I suggest actually raising the system pressure a bit. The mercury pressuretrol has an advantage in being able to see if it shuts off on pressure and if it is actually tilting back into position when it should. Those can stick "off" at very low settings, also mercury switches must be level!



That 2" pipe feeding two 2.5" mains is a significant restriction so a setting of 3 psi MAIN and setting the DIFF closer to 2 is what I would try. After getting your main vents straightened out. Heck, even without main vents that boiler should be able to heat through radiator vents only, not that heat distribution and efficiency would be where it needs to be. I'm just saying you have several problems with additive deleterious effects.



I'll add another too. Make sure there's nothing in the HW loops in series with the steam thermostat. So:



1. Main vents.

2. Raise pressure to 3, diff 2

3. Make sure pressuretrol is level

4. Watch to see if there's anything strange going on, like the steam side is only working if one of the HW zones is also calling for heat (the more I think about it, the more likely this seems)

5. Lose the cyclegard.

6. Have that supply piping corrected eventually.



That's my take. FWIW.

@ttekushan
I'm curious, why do you want him running 1 to 3 PSI?

KC_Jones

Abracadabra said:

I see a cyclegard on there

I'm guessing that's what's shutting down the burner every so often.

It's not shutting down every so often it's shutting down and staying off during a heat call for minutes even an hour or more. "I has now been an hour an 10 minutes since I turned the thermostat up to 72 and the boiler has fired for a total of 9 minutes, with about 5 or 6 occurrences of the motor starting but not firing." How could the cyclegard be causing that?

pjmilford

You bring up something that I think is happening, but up to now, i was only thinking that my mind was playing tricks on me. on point #4, in the morning, it takes hours for the house to go from 65 to 69. to recap, 65 is my setback, 4:30 calls for 67, 6:00 calls for 69......but I have said to my wife before, that it only seems to kick up the heat in the steam system, only after i raise the thermostat in the kitchen manally each morning. so there may very well be something to when the kitchen HW zone calls for heat, that may be what finally kicks on the steam zone? I am not sure what that means, but this afternoon, the steam side never came on for more than 9 mnutes over a couple of hours, but when the kitchen called for heat, the steam side finally moved after only about 15 or 20 minutes, after not moving at all for a couple of hours......so what is this saying to me again?

pjmilford

I have also ordered 4 #1 gortons that should be in friday or saturday and I will put those on this weekend and repost at that point....

ttekushan_3

Oh, hi @ChrisJ,

I'd like him to try the 3 psi with a 2 psi subtractive diff since the low settings can be problematic on those controls and I also don't think he's getting anything resembling 1 or 1.5 psi on those two 2.5" mains, particularly with that 2" bull nose Tee being fed by a single 2" pipe nipple and elbows.

My thinking is that two issues occurring simultaneously could cause the trouble seen: the restriction and a possibility of flakey operation of the pressuretrol at very low settings. Perhaps the pressuretrol may be too sensitive at those low settings and shut off the boiler at only a few ounces of actual pressure at the front of the mains and virtually 0 psi at the ends.

I figure it's worth a try. I hear you though. I don't run anything more than 2 psi, with ounces preferred; but a strange piping arrangement between the pressuretrol/boiler and the mains throws a (pipe) wrench in the works! Once that piping is corrected, then 3 psi is too much, I agree.

But I'm still curious about the wiring of the thermostats…

Mark N

I wonder if its the aquastat? Could be be wired into the steam thermostat circuit. That would make it impossible to make steam.

KC_Jones

ttekushan said:

Oh, hi @ChrisJ,



I'd like him to try the 3 psi with a 2 psi subtractive diff since the low settings can be problematic on those controls and I also don't think he's getting anything resembling 1 or 1.5 psi on those two 2.5" mains, particularly with that 2" bull nose Tee being fed by a single 2" pipe nipple and elbows.



My thinking is that two issues occurring simultaneously could cause the trouble seen: the restriction and a possibility of flakey operation of the pressuretrol at very low settings. Perhaps the pressuretrol may be too sensitive at those low settings and shut off the boiler at only a few ounces of actual pressure at the front of the mains and virtually 0 psi at the ends.



I figure it's worth a try. I hear you though. I don't run anything more than 2 psi, with ounces preferred; but a strange piping arrangement between the pressuretrol/boiler and the mains throws a (pipe) wrench in the works! Once that piping is corrected, then 3 psi is too much, I agree.



But I'm still curious about the wiring of the thermostats…

The problem with your theory is he is currently getting no PSI, and no steam so how is raising a control that is essentially doing nothing going to help? I really believe he needs someone in there that knows controls to take a look at ALL the wiring in the system. Obviously his current contractor doesn't know what's going on. Once that is resolved the other stuff can be addressed. I would put the piping fix high on the list as it's not helping anything and could potentially hurt any vent balancing he tries to do.

ChrisJ

Good news is with a mercury type pressuretrol you can actually see it trip by watching the mercury bulb.

ttekushan_3

Another thing. Does the domestic hot water have priority? On this kind of arrangement it should be irrelevant so long as the boiler aquastat is satisfied. But who knows if the DHW is wired to also have veto power over the steam thermostat.

Is the Cyclegard wired to the burner in such a way that it interrupts the burner on ANY heating demand? The HW sides won't notice much but the steam side sure will.

I'm visualizing a scenario where the steam thermostat only works if your HW zones are also calling for heat but only if the DHW is not. And only if the Cyclegard isn't in the mood to further cut off the steam side at the knees when all the other stars align to allow steam to be generated. But before the pressuretrol shuts the burner off because of the piping out of the boiler header. Whew!

I can see why you never get any heat at the radiators!

P.S. You're not blowing thru those main vents while they're upside down are you?

ttekushan_3

@ChrisJ

Just one of the many things to love about the mercury controls.

Jamie Hall

ChrisJ said:

ttekushan said:

Good call, @Abracadabra



To that I suggest actually raising the system pressure a bit. The mercury pressuretrol has an advantage in being able to see if it shuts off on pressure and if it is actually tilting back into position when it should. Those can stick "off" at very low settings, also mercury switches must be level!



That 2" pipe feeding two 2.5" mains is a significant restriction so a setting of 3 psi MAIN and setting the DIFF closer to 2 is what I would try. After getting your main vents straightened out. Heck, even without main vents that boiler should be able to heat through radiator vents only, not that heat distribution and efficiency would be where it needs to be. I'm just saying you have several problems with additive deleterious effects.



I'll add another too. Make sure there's nothing in the HW loops in series with the steam thermostat. So:



1. Main vents.

2. Raise pressure to 3, diff 2

3. Make sure pressuretrol is level

4. Watch to see if there's anything strange going on, like the steam side is only working if one of the HW zones is also calling for heat (the more I think about it, the more likely this seems)

5. Lose the cyclegard.

6. Have that supply piping corrected eventually.



That's my take. FWIW.

@ttekushan
I'm curious, why do you want him running 1 to 3 PSI?

Take a good look at that pressuretrol: it's set to slightly less than 2 for the cutout, with a diff. of 2, which is subtractive. You have to watch those puppies -- the mercury ones are not like the blue box ones! It's a wonder it resets at all... @ttekushan 's advice is exactly right for that one.

ChrisJ

Jamie Hall said:

ChrisJ said:

ttekushan said:

Good call, @Abracadabra



To that I suggest actually raising the system pressure a bit. The mercury pressuretrol has an advantage in being able to see if it shuts off on pressure and if it is actually tilting back into position when it should. Those can stick "off" at very low settings, also mercury switches must be level!



That 2" pipe feeding two 2.5" mains is a significant restriction so a setting of 3 psi MAIN and setting the DIFF closer to 2 is what I would try. After getting your main vents straightened out. Heck, even without main vents that boiler should be able to heat through radiator vents only, not that heat distribution and efficiency would be where it needs to be. I'm just saying you have several problems with additive deleterious effects.



I'll add another too. Make sure there's nothing in the HW loops in series with the steam thermostat. So:



1. Main vents.

2. Raise pressure to 3, diff 2

3. Make sure pressuretrol is level

4. Watch to see if there's anything strange going on, like the steam side is only working if one of the HW zones is also calling for heat (the more I think about it, the more likely this seems)

5. Lose the cyclegard.

6. Have that supply piping corrected eventually.



That's my take. FWIW.

@ttekushan
I'm curious, why do you want him running 1 to 3 PSI?

Take a good look at that pressuretrol: it's set to slightly less than 2 for the cutout, with a diff. of 2, which is subtractive. You have to watch those puppies -- the mercury ones are not like the blue box ones! It's a wonder it resets at all... @ttekushan 's advice is exactly right for that one.

Ok.

Here's mine from a few years ago, but I haven't changed the setting since I set it up for 0.5 - 1.5 PSI.

hvacfreak2

Just to throw this into the mix ,

The ewlc is right at the waterline on mine , if things are not right with the water it will lock out in a hurry. CG or not Burnham is not allowing for anything crazy with the water it seems. The current offering for water cut offs are the MM PS-108 , CG , and MM 67 according to my manual.

pjmilford

So it does sound very likely that I have a wiring problem with the thermostat on the steam side, because I know that when I call for heat on both of the HW sides, the boiler kicks on right away and does its jobs in a matter of a very few minutes.
see if this answers any questions..

I made sure that both HW thermostats are not calling for heat

I then called for the steam thermostat to heat, the thermostat turns on and indicates Heat On. I go downstairs and look at my TACO Zone Valve control and it has one yellow "thermostat" light on, but the burner is not running.....a few seconds go by and the yellow light goes out.

I then go back to my kithcen thermostat (HW) and call for that to come on, which it does almost immediately. I go downstairs and the TACO ZVC shows a yellow light for the kitchen and a red light for the zone valve and the system is running. I let that go for a few minutes and go back to the kitchen thermostat and turn it down so that it no longer calls for heat. the boiler immediately shuts off and all the lights go back to off downstairs. But the steam thermostat upstairs is still calling for heat, but the boiler is not recognizing this......

I live in Milford, NH..........there is nobody in NH listed on this websites list of contractors........does anyone have any suggestions for me?

BobC

If the wiring is wrong you have a problem.

If both hot water zones work right but the steam thermostat won't turn the boiler (but it does seem to be turning something on) on it's probably something in the relay area. Go over that Taco and make sure there aren't any lose wires, if that doesn't work you have to find someone who understands how they should be wired.

Hopefully someone will offer up a name for you.

Bob

Jamie Hall

Milford is a little out of the way, but if recollection serves I believe that Charles Garrity (413.841.6726) might go up that way.

BobC

i don''t know which Taco relay you have but here is the manual for the SR50X, it may be of some help to you or whoever tries to troubleshoot this.

Bob