One Rad cold

Kbalz

Hi, just purchased a 1930's home a few weeks ago, and it has a single pipe steam boiler system. Its about a 40 year old Burnham.



We had the burners cleaned, and the guy showed me a little bit about the system.. I've also been reading online materials about the things to look at weekly etc.



All of the radiator's air vents were closed when I moved in. I opened them up according to what I read online which was the biggest rads should be fully open, and the smaller rads should be the most closed (but not completely closed).



So far all of the rads have been heating nicely. But last night my son's room was ICE COLD compared to every other room, his radiator was cold to the touch, while I could melt a crayon on my room's rad. Prior to last night, my son's room was always the warmest in the house.



The bad rad's air vent was still set (mostly open) properly. What else can I check, that would suddenly shut one down?



I did check the pitch of all rads, they are NEAR level. I understand they should pitch, but I'm not exactly sure how much they should pitch? Could this be the problem for NO heat?



Thanks in advance,



Kurt

BobC

Non heating radiator

First of all welcome to the world of steam heat. It's best to educate yourself on how it works because most contractors really don't understand it very well. Browse around the board to see what problems others are having, you may find answers there. Also you might want to consider buying some of the books that Dan offers for sale under the SHOP heading, I've bought a couple of them and they do a great job of explaining how the system should work; they will pay for themselves many times over.



Now to your specific problem. What make of air vent does the radiator have? Can you hear air being expelled from the cold radiator air vent? If you can't hear the air coming out hold a piece of tissue paper above it and see if it's moving.



It's possible some crud is blocking the vent, you could try swapping vents between radiators to see if the problem moves. If that indicates a bad vent you can try boiling the bad vent in vinegar for a half hour or so or pick one up at the hardware store. Try to stick with a name brand like Gorton, Hoffman, or Maid O Mist. Also make sure the radiator supply valve is open fully on all the radiators (full counterclockwise), partially closed supply valves will cause problems.



Also check the basement piping and the radiator to make sure the condensing steam can drain back towards the boiler. If you have a low spot in the supply pipe or the radiator is sloped back towards the air vent it can block the steam. Don't trust your eyes, use a level. While your down there see if the main steam vent is working correctly and note the name and model number of it.



If those suggestions don't pan out, post some pictures of that radiator and it's vent. Also pictures of the boiler, the piping around it, and of the main steam main (and the main steam vent).



Bob

Kbalz

Re:

BobC - excellent info, thanks. I'll try moving the vent tonight, as well as taking pictures/measurements of my system.



I saw a video on TOH - where the guy changed an air vent.. what exactly is the white tape / product called that is used to wrap the threads in?

BobC

sealant

That is teflon tape, it's used as a sealant and it makes it a lot easier to get things apart in 10 years! One roll will last a long time. Pipe sealant in a can  works just as well but the Teflon tape is a lot neater.



Bob

Kbalz

Worked

I switched the Cold Rad's airvent with one of the rads that are always hot - and now BOTH radiators work!



So the problem did not move as I expected, it went away. Note, that neither of the two had any tape/sealant on the air vent.. should this be something that I proactively add to all air vents in the system?



Also, the air vents themselves do not seem to have a brand name printed on them. They just say 'China' engraved on the side. I did some Googling, and it looks exactly like these Watts Water brand: AMAZON LINK



I didn't have time to snap pictures, but I'm concerned about my main vent - it looks no bigger than a golf ball, and the brands you mention look much nicer like they were on a submarine. I'll try to get pictures taken soon, and I'll start a new post for that topic later.

BobC

Always nice to win one

Removing the vent may have dislodged so crap and enabled the vent to work again. The teflon tape is always a good thing both to seal the joint and to make it easier to get things apart a decade down the road.



Those Chinese vent have a history of being problematic but sometimes they are all you find at the big box stores. If you start to calculate the volume of air in each radiator and the pipe that feeds it you will know what size vent you should have. usually the biggest vent goes on the largest radiator. i use the Hoffman 1A's because they are adjustable



Dan's book "Greening Steam" has tables that list the volume of radiators and piping; it also has the capacities of all the common air vents so you can match them up.  To get a good understanding of how steam systems work his "The Lost Art of Steam Heating" is a great resource. Pexsupply is a good online source for vents - http://www.pexsupply.com/Air-Valves-300000.



The mains have to be vented fast, the vent you need is dictated by the  main(s) volume; that lets you get steam to all the radiators at about the same time. Usually you vent the radiators slower, adjusting the vent rates so they all come up together.



Bob

Kbalz

Steam

I'll be asking Santa for some of these books - my neighbors have recommended "We got Steam Heat" as well.

Volvoguy87

Vents and books.

Get the "A Steamy Deal Package" and also get "Greening Steam."  Interesting reading, especially Greening Steam.  Use the "Find a Contractor" section on here to find a pro in your area.  Those Chinese vents do have a problematic history.  I like Hoffman and Gorton rad vents.  Determine the volume of air in your radiators to be vented and size replacement vents accordingly based upon the volume of air they can vent per minute.  If you buy several vents at once, it's likely cheaper to order them by the case.



Assessing your system would be a very good idea since it's new to you.  You'll want to get familiar with the care and feeding of a steam system, like how to flush the low water cutoff, the returns, and the boiler's mud leg.  How to tell if the boiler is priming and foaming and what the different noises mean is also a very good idea.  Making sure the mains are vented PROPERLY can save a nice pocketful of cash when you pay your utility bills.



Again, get the books, read up, and talk to a reputable pro.

Steam is great, congratulations!

Dave

Kbalz

water

So a few days went by - and then the radiator was again cold.. I checked the water level in the boiler, the sight glass read 25% full..! After filling to recommended level, the radiator was again working properly.



Thinking back, I think I filled the water the same day I swapped the air vents.. so the whole time that was probably the issue.

crash2009

Start a log book

I just started logging every little change I-do incase I have to un-do.  I am told this is especially important with adding water.  So far I am beginning to see patterns such as I have to add 1/2 inch of water every 10 days.  I just enter the date and the time, any observations, and changes.  If you ever have a pro over to your house they will ask to see the book to help them troubleshoot. 

BobC

Water?

I agree with Crash about keeping a log, I've done it for a while now. It really helps you tie things down without relying on memory alone and it forces you to be aware of whats going on with your system.



If you have to add water that often, I would look around to see where it's going. Once or twice a month is normal, more often is a concern.



Bob

Steve_210

a water meter

would be a good idea then you know exactly how much water you use.

Kbalz

in that case

I have a concern, I'm adding about 2-4 inches every week, and it hasn't been cold outside yet (Michigan).

BobC

Too much water!

If you are adding 2-4 inches (in the sight glass) of water in a week and you can't see any evidence of a leak (under the boiler?) then it may be a hole in the boiler above the water line. When the boiler is firing go outside and look at your chimney. If you see a lot of white smoke that might just be water vapor (steam) and not smoke.



You have to figure out where all that water is going so you don't end up with an emergency replacement of your boiler in the depths of winter. If that happens you will pay through the nose and probably not get a good install to boot.



Bob

Kbalz

Two cold rads

Hi Everyone,



My problem has returned, and expanded. I thought that the cold radiator was related to the water level being low, however this is not the case.



Last night around 6pm, all radiators were hot except my son's room.. so I checked the water level and of course it was low. I let the system off for about 90 minutes, filled the boiler to the proper level, and fired back up. By 9pm, all radiators were hot, except my son's room again! It remained this way all night.



We have a guest room next to my son's room that we have not been inside that often.. I checked the radiator in this guest room, and noticed that radiator is also cold.



In my son's room, I've increased pitched the radiator (it was nearly level, now nicely pitched).





Since I've posted last, I have not checked for the presence of chimney steam.. Its dark when I get home and forget in the morning!







Could a leak in the boiler as you describe, cause these two cold radiators?



Tonight I'll be taking pictures and drawing some pipe layouts.

brian_44

When are you checking the water level?

Kbalz, This may sound stupid...but are you checking the water level while the boiler is in mid cycle? If so, it's completely normal for the water in the sight glass to appear low. DO NOT ADD WATER at that point!

if, however, you're seeing the water at a lower level once the cycle is over and the system has had some time to cool down, that's different.



Just don't want to overlook the obvious!

Kbalz

after ~90 minutes

Brian, correct, I allowed the system to cool off for about 1.5 hours (is that enough time?). Then I need to add about 2 or 3 inches of water. I must do this every 3-6 days.



I'm starting my log book to get a more accurate picture of the fillings, as BobC indicated the frequency and amount of filling is a concern for me.





I also don't think I've ever seen my pressure gauge move.. it is always sitting at 0. How often should the gauge move?

Steamhead

You're losing water too fast

if there are no obvious leaks, the likely problem is a hole above the boiler's waterline. If you see white plumes coming from the chimney when the boiler is running, that's another sign. Have a pro come in and look at it- you may need a new boiler. 

Kbalz

risk

If that is the case, a leak above the water line - what are the risks of doing nothing? Will I just have to keep adding water?

Kbalz

no smoke

I ran home during lunch, and fired on the boiler, watched the chimney for about 5 minutes. I did not see any smoke, just some small heat waves (like you see coming off hot asphalt in the middle of summer)



I would have stayed longer to watch, but I ran out of time. So first indication is, there is no smoke coming out of the chimney.

BobC

Flooding the boiler

If you don't have water vapor coming out of the chimney and assuming the boiler was up to steam when you were watching, you can test for holes above the water line by flooding the boiler.



With the boiler warm or cold, open the feed and put in enough water to get a few inches above the sight glass and see if any leaks show up. One way to tell if you are high enough with the water is to put a short hose on the boiler drain and hold that hose up so it is about the same level as the top of the boiler case and fill it till the hose overflows (boiler drain open at this point). Your using the hose as a water level to see what the level is inside the boiler.



Give it 10-20 minutes to see if anything comes dribbling out from the boiler itself. If nothing comes out you may have a leak into the combustion chamber rather than to the outside of the boiler but that should have shown up as white smoke in the chimney..



After doing the test drain enough water off to get the sight glass level correct and you should be set to run.



Bob

brian_44

Yep..plenty of time

If you're letting it cool down that long, the water line would have returned to normal way before that.

You're getting some good direction here by others. If I had to guess (and it's a total guess) I'd say you have a hole above your water line which is why you don't build enough pressure to ever register a reading on your pressure gauge (not that that's a bad thing under normal circumstances) along with the loss of ability to get heat to some of your rads.



Hope you find your issue soon. if you have any doubt or hesitation, I'd get a steam heat pro out there asap to get to the cause immediately. Worst case is you need a new boiler...better now than in mid Jan at 19 degrees! (BTW- 40 yr old boiler...not a bad run, but u can probably gain a decent amount of efficiency.)

jpf321

a buried return ..

is a leaking return and may be the culprit .. do you have any pipes which disappear underground or to some other unforeseen place? 

Kbalz

all visible

Nope, all of the main steam pipe is visible, I'm going to post pictures below.

Kbalz

understood

Bob, it will be a few days before I can try this (out of town this weekend).



there is a new bit of information, I'm posting it below with pictures. The forum keeps indenting our conversation further and further, so I'm replying below to straighten it out a little.

Kbalz

Development

I got home last night, and went up to my son's room with the cold radiator. The guest room, also had a cold radiator (as expected). I noticed a smell today, my wife did as well - she said it was the smell of death.. but I thought it was more of a slight metallic smell.. it was in both rooms with the cold radiators. What does that mean?



Anyways, I situated myself in my son's room, and I could hear the steam (or boiler) via the radiator, it was calling to me.. so I decided to take OFF the air vent. Cold air spat out. I held a tissue over the open air hole, and the tissue was wiggling around. Less than 3 minutes passes, and the pipe that feeds the radiator is hot to the touch.. a few more minutes pass, and half the radiator is hot. I run the guest room, and that radiator is hot as well !!! I dance, and put the air vent back on. About two hours later, both are again cold (while the rest of the radiators in the home are hot).



But if you look back in this thread, I've already swapped air vents with another radiator (Dining room).. To date, the dining room has never been cold. What can we conclude with this new info?





I have attached a sketch I just made.. its not to scale by any means. I don't know if the pipes that feed radiators all originate from the Main Steam Pipe, or if they tee off of one another..



The pictures are of the boiler and some of the main steam pipe. The basement (except for the boiler room) is finished.. and the main steam pipe was aesthetically "boxed" in. The main steam pipe is mostly insulated.. some of the pipe is exposed in the finished portion of the basement, I'm assuming that was done so some heat radiated from it.



Also, notice my glorious main steam vent. Very underwhelming. I couldn't get close enough to it to read what brand it was, and I don't know how to test if it is even working. Any tips are welcome. Thanks!

BobC

Main vent

That main vent looks much to small. As an examble if your main was a 2" pipe (ID) and 30 ft long it would contain 1.13 cu ft of air. If the pipe is larger or longer it would contain more air. All that air has to be expelled before all the radiators get steam. To vent that 30 ft 2" main I would use a Gorton #2 which is  larger than you need be cheaper than having to use two smaller vents. Insufficient venting causes you to burn more fuel every time the boiler runs.



The fact you got plenty of steam by removing the vent on that radiator tells be your venting is not balanced. Steam will follow the path of least resistance and the hole you probably have in the boiler makes things a little crazy not to mention driving your heating bill through the roof. Your mains have to be vented first so steam is available to all of your radiators, then each radiator has to be vented according to it's internal volume and that of the pipe that feeds that one radiator. Usually you want bigger vents on big radiators and smaller vents on smaller radiators. Adjustable vents make it a bet easier because you don't have to buy different sized vents, you just dial the amount of venting yo need for that particular radiator. Good vents are not cheap but they last a long time.



Your main vent has to be replaced, don't start messing with radiator venting till that is done. Make a list of the size of your radiators (# of columns, # of sections, and height) and what model vent each one has.



Bob

brian_44

Example...

I had almost the exact same main vent when I moved into our home. It was almost like having nothing! Here's what i did and it did wonders for speeding up the time to heat the rads....

Kbalz

Got one on order

I've ordered one - should be early next week. I'm by no means a plumber, any tips you have to install it? It appears my current vent threading is larger than 1/2".. but I didn't have time at lunch to measure it..

Kbalz

Measure

How should I measure the Main Steam Pipe? The outer diameter is around 2 and 3/8ths inch. Do I measure the vertical portion that comes off of the boiler? And what about the T's that break off to go UP to the next floors?



Do I count any pipe that is on the boiler-side of the current main vent?

crash2009

circumference

I'm not sure what lengths Bob wants you to measure.  But, to figure out the pipe size you can use a sewing tape measure, or you could use a piece of string.  I know Bob will need the circumference of the pipe.  He has a chart that will tell him what size the pipe is based upon the circumference.

BobC

Pipe volume

2-3/8" OD is a 2" ID pipe.



What I need is approximately how many feet of what size pipe is between that main vent and the steam output of the boiler (top of the boiler to that main vent). (any pipes that go to upper floors will be vented by that radiator vent. The length numbers only have to be approximate, 10-20% accuracy is fine. This does not include any of the radiator feed pipes.



Once we have this information we will know the volume of air we are dealing with and can determine what capacity vent you need.





As far as the radiators venting goes you have to know what size radiator and about how many feet of pipe feed it. In my system the 1st floor rads are fed by 1-1/4" pipe while the second floors are fed by 1-1/2" pipe, yours may be different. With the information on each radiator/feed pipe we can guestimate the venting requirement needed for each radiator



Bob

brian_44

It's probably 3/4...

...but you want to measure to make sure. For the #2, you'll likely need to go to the home center. They sell the little pieces of black pipe to create the antler you see in mine. You'll probably need to get a T fitting with a reduced thread on top. you can sort of see it in my photo.

Make sure to do the antler to keep the moisture from being able to work it's way to the vent.

Kbalz

seal

Do I just use a ton of teflon to join the pipes, or is there another product involved? Thanks for the tips here

BobC

pipe sealant

Teflon tape or pipe dope, if you use pipe dope don't go crazy with it or you might be skimming the boiler to clean out anything that gets into the boilers water. Also one nice aspect of either one is it will enable you to get the pipes apart in future years without a lot of cursing.



Bob

Kbalz

Long Post

EDIT: I was using poor terminology, it has been updated.



I was out of town for several days, hence the delay on my response. I knew when I returned, the boiler would need filling.. the sight glass had only about two inches showing. I added water, and dumped the two gallon bucket that sits under the low water cut off..



Today (about 24 hours later), the boiler required more filling, and the low water cut off bucket was about 1/3 full (it drip leaks).. I got busy, and overfilled the boiler. I drained the excess water via the blow off drain. then I finally made the connection!



The leak is not inside the boiler.. the dang shut off that drains out of the bottom of the low water cutoff doesn't shut all the way, and drips about a 1/2 gallon of water per day. I was mindlessly emptying this bucket (pictured below), thinking it had nothing to do with the leak.



Reason why I thought it had nothing to do with the leak: we had a Heating company come a few months ago to clean the burners.. I asked him how much water a system like this held.. He admitted he didn't know much about steam boilers, so he said maybe 80 gallons. LOL. So I figured the gallon in the bucket every couple days wasn't a big deal.



No matter how hard I turn, the LWC leak will no stop.. that is a story for another thread I guess.



Anyways, here are the numbers:



Main Steam Pipe: 70' and 4 inches



Radiators - I've attached two types of Radiator Air vents that are in my home. A (cheap Chinese) and B (good quality). I also wasn't sure how to describe the width and such of the radiator parts, see my labeled picture as a reference.



I measured the feed pipe's using circumference / pi = OD



First Floor



Dining Room

OD: ~1.7"

H: 34"

W: 8

5

Vent: A



FamilyRoom1

OD: ~1.7"

H: 24"

W: 24

5

Vent: B



FamilyRoom2

OD: ~1.7"

H: 34"

W: 5

5

Vent: B



2nd Floor



Bath:

OD: ~1.43"

H: 27"

W: 6

3

Vent: A



MasterBR:

OD: ~1.7"

H: 34"

W: 7

6

Vent: A



BR1 (Son's Room)

OD: ~1.7"

H: 34"

W: 7

5

Vent: A



BR2 (Guest Room)

OD: ~1.7"

H: 34"

W: 6

5

Vent: A

jamesm

One rad cold No answers

Good evening. I have the "one rad cold "problem going on, have replaced release valves, even removed them. Have checked the turn off, even removed the top of it. Have pushed a wire down the pipe to check for blockage. Pipe is hot from main line on the way up but is COLD by the time it gets to the rad. I have looked in the pipe with the turn off top removed, as welll as listened and felt. A tiny bit of cold air puffs up sporadically. I have turned up the pressure. This part of the system acts totally unlike any other part. I woud swear the main line is blocked but condensate seems to be returning thru it and the main is hot all the way. If I took the top off a turn off in any other room I would be burned immediately. Need some ideas on this one.

jamesm

One rad cold No answers

Good evening. I have the "one rad cold "problem going on, have replaced release valves, even removed them. Have checked the turn off, even removed the top of it. Have pushed a wire down the pipe to check for blockage. Pipe is hot from main line on the way up but is COLD by the time it gets to the rad. I have looked in the pipe with the turn off top removed, as welll as listened and felt. A tiny bit of cold air puffs up sporadically. I have turned up the pressure. This part of the system acts totally unlike any other part. I woud swear the main line is blocked but condensate seems to be returning thru it and the main is hot all the way. If I took the top off a turn off in any other room I would be burned immediately. Need some ideas on this one

Rod

Cold Radiator

Hi - If you can check to see if the is a sag in the pipe leading to the radiator which would cause condensate (water) to pool. Does this line have plenty of slope?

- Rod

Rod

Radiator Vents

Hi- i just finished reading through this thread and am a little bit confused by the terminology used. Is the place where your leak occurs the blow off valve on the Low Water Cut Off? (See attached labeled picture) If so you can just replace the present valve with a good ball valve form Home Depot. I 'd add a bit more piping and route it to a more convenient location.

Radiator Slope- Check your radiators and see that they have a slight slope towards the inlet pipe. This should be just enough to :"encourage" the condensate (water) to flow out of the radiator. Too much slope can cause problems!  I use quarters ($0.25 pieces) to shim up the legs at the end away from the steam inlet pipe. After I;ve found the optimum height I replace the quarters with a shim.  Use a carpenter's bubble level to check the slope as it is sometimes hard to guess especially in older houses with sagging floors. (I've attached a diagram on one pipe radiators)



Radiator Vents-  I checked Gerry & Steve's excellent venting chart and if the vent labeled "Vent A" in your pictures is a  Watts SWA vent, the venting capacity is very small. The Hoffman 1A wide open is 2 1/2 times more venting and also there is a note on the test chart showing that the SWA was from Taiwan and gave sporadic readings "right out of the box". I'd suggest a switch to all Hoffman 1A s which are available from Pex Supply on the internet. If nothing else try a few first on the problem radiators.and see what that does. 

- Rod

Kbalz

OOPS

Sorry about that, where ever I said pressuretrol, I meant the low water cut off