One radiator not heating (one-pipe steam system)

Matt Funk

Per Dan's books that I have been reading, there are several possible causes. The easy one to check is if your supply valve to the radiator is fully opened. All your valves should be either fully opened or fully closed.

Next, check to see if the pipes are visible and accessible under the floor. Assuming this is a 1st floor radiator, you can probably see the supply line in the basement. Check to see if the pipe is insulated. If not, that could be contributing to your problem. (the steam may condense too quickly)

Lastly, the steam can not get into places where air is trapped. If you have a bad air vent either on your main supplying the radiator, or on the radiator itself, the radiator will not get steam. If the pressure on your system is set too high, like above 2 PSI, the pressure will slam the vents shut, and they won't release the air either.

So, there are a few basic things you can check for before you call in the troops. At least that way, you can help narrow down the possible causes so you can more successfully troubleshoot with a professional.

Good luck!

-Matt

Jason Lehr

One-pipe steam system - one radiator not heating

My wife and i just moved into a 1929 house with a single-pipe steam system. We love the house and the steam heat having come from a hot air system (my wife has allergies, and the steam system has made an immediate impact). The only issue is that one of the radiators doesn't heat (of course, it's in the room we spend the most time in.) Well, that's not entirely true, it heats, but it's the last radiator to heat, and when it eventually does, only the first few cells get hot. During the inspection process, we had the system serviced by a local HVAC company that had a maintenance agreement with the previous owner. The tech that came out said that the radiator in question was the last in the system, so it would have to wait for all the other radiators to get hot before steam was diverted to it and it heated. Well, it's been a week since we moved in (it was 70 when we moved, but has rarely peaked above 40 since then) and this one radiator is cold, cold, cold. When it does get hot, it's only the first four or five cells that get hot. There's a new vent in place, set to 'fast' and the radiator is level, if not a bit slanted toward the feed line. All the other rads in the house work gangbusters, but this one just doesn't get hot. Worse yet, it's in a room that has a lot of windows, so it's likely to get colder faster. The room is an addition that was added at some point (don't know when), so it makes sense that it was added after the system was set up, and thus the last to heat (at least, that makes sense to me...) but the fact that it never heats all the way through is troubling to me. There is a bit of hammering, but nothing i would describe as severe or even moderate (all steam systems are a bit loud, aren't they?).
At any rate, sorry for the rambling - i just want to get this issue sorted out before the summer while it's still cold outside so it's one less thing i have to deal with in the fall. Any help is greatly appreciated.

Aaron_2

I think we need more info...like how the piping for that radiator runs, where it connects to the main piping, where is the main vent located on the main, and in relation to where the piping for this radiator and the main vent is? Is there a main vent on the system? Steam systems are not noisey if they are running correctly. What is the pressuretrol set for? it should be set for 1psi cutout and 1/2 psi cutin. Or even less if possible. Is the boiler big enough to handle this radiator and all of the other radiators? All good stuff to ask and find the answers to.

Unknown

are the pipes

Are the main pipes insulated? Bangings and noises from steam system may works for me as I'm hearing imparied but for you, the system shud be quiet and perhaps a few low hissings from the vents at start up... As end of the heating season approachs(sp) hope u'll get some of Dan's steam heating books from this site and better educate yourself and get a real BOILER pro to work on the system

Jason Lehr

All good questions - here are some answers

Wow, these are all good questions...Here's more info:

-Radiator is a first floor rad, so i'll check out and describe the piping when i get home from work today.

-The vent on the radiator in question does work. I can hear air escaping out of it as the first few cells get hot.

-I don't know where the main vent is, or if there even is one you're not referring to the (overpressure?) vent on the boiler, are you? What should i be looking for?

-The pressure gauge on the boiler reads less than 1 psi, but i don't know anything about a pressuretrol.

-The pipes are well insulated in the basement.

-The supply valve on this rad is fully open.

I'm looking forward to learning about my steam system - so far i love it. Thanks for everyone's input!

Jim Bennett

The Good Book...

You might want to pick up this book.

http://www.heatinghelp.com/shopcart/product.cfm?category=2-109

And keep asking questions, this is the place to learn.

jim

Daniel_3

I used to know a Matt Funk. You wouldn't happen to have lived in Worcester several years ago, did you?

Al Corelli_2

Vent Position

Is the vent on the opposite side of the supply pipe, or on the same side?



Is the vent located approximately half-way down the radiator or is it near the top?

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Jason Lehr

more answers

The vent is located on the opposite side of the supply pipe, and is about half-way down.

I also checked out the pressuretrol - it looks like it's set for 1psi cutout and 1/2 psi cutin.

I couldn't find a main vent though. I looked on the main supply and on the return, but maybe i missed something.

Also, the pipe that feeds this rad only feeds this rad. The header doesn't really look like headers i've seen in diagrams and photos on the web (my sole experience in all of this). I've attached a photo of it, with the pipe that feeds the rad in question highlighted. It is a bit cooler than the other pipes in the system.

I know it's April, and things in the heating world should be cooling down (quite literally), but they're predicting more snow to come. Ugh.

Warren_3

No heat @ 1 radiator

At face value it sounds like a simple "bad air vent". Although you have had a new one put on it doesn't mean it is working properly. I would recommend replacing it a second time ( it is not a very expensive repair). If this does not work the likely hood of 3 bad #1 ventrites is low. I would look @ the installation of the radiator itself. Since, from what I have read, the origanal installed radiators are working fine. On a properly installed steam system distance from the boiler does not matter, all radiators will heat up fairly evenly. Since this radiator appears to be "an after thought" & not part of the original install it may have to do with 1) where it comes off the main 2) size of pipe feeding radiator 3) lenght of pipe 3) pitch 4) size of boiler/ system vs radiator size the list goes on.
Unfortunately in may be " nonrepairable" depending on how it was intalled & the system itself. Yoiu really need a good contractor out htere who knows steam. & there are other sollutions, but again try the air vent 1st. Best of luck.
Warren

Daniel_3

Other then seriously incorrect piping for the branches off the main (seems like there is not even a proper main in that pic) many will say bleh! to copper but that is not the issue here as seen in the way the piping exists. If you look at any diagrams in the library here of one pipe steam you will see that the the steam mains must be at least 2 inches and the branches for all the radiators must either tee-off individually from the main at a 90^ or 45^ angle, all with proper pitch back towards the main for the return of condensate. I wish I had a picture of what I found on my one-pipe steam concerning two rads where they were both connected by copper to an angle valve which then connected to the main by means of a single 1" copper line. The copper for the rads was 3/4" and 1" respectively.(way too small and improperly piped but the adjustable venting actually worked) I replaced it all with black pipe separating the rads from one another as of late.

The only quick remedy to get heat to that radiator(looks to be fed by 1 1/4" piping) without tearing out pipes would be to throttle (vent rate adjustment as relating to the whole system) the radiators in the rest of the house by using fast venting adjustable vents keeping the radiators located upon that same pipe line as the cold rad with a low venting rate and the cold rad with a high venting rate. This would be in the interim but I suggest posting more pics of all the piping in the basement and getting a real steam pro to look at the piping and restore the proper functional dynamics.

As Warren said down below, steam will not be displeased with a long run (distance) but it will be affected greatly by turns and twists as seen in the pic. It seems that the vertical copper pipe in the pic is either your condensate return or a riser branch off the main to which there are several branches off of that; no wonder the cold rad won't heat since there are three possibilities for the steam to seek out, the longest run being connected in a strange way. It also could be that the lower horizontal copper pipe coming in the right side of the picture could be the primary feed. If the latter is the case the steam doesn't want to make a u-turn as it takes too much trouble to do so. I'm sure this can be remedied rather easily with the right professional.

Daniel_3

Jason, Attached are two pictures of how steam risers must be installed for the proper function of a one-pipe parallel flow steam system. In one picture you see a 90^ tee-off and in another two 45^ tee-offs (and no this isn't golf . Each of those pipes feeds one radiator. It is proper practice to have the primary branch to be one size larger than the vertical riser that feeds the radiator. ie. 1 1/2" off the main to 1 1/4" to the radiator at the vertical turn. Daniel

Jason Lehr

Daniel - Thanks for all of the info. I've been scratching my head a little looking at diagrams of one-pipe steam systems wondering why mine doesn't look anything like anything else i've seen. The vertical copper pipe in my attached photo is my "main" - it goes right into the boiler. Another strange thing is that the rad that isn't heating is on the opposite side the wall where another rad is heating great. In fact, that rad is fed by the pipe directly to the left of the highlighted pipe. That pipe has other pipes branching off for other rads in the house - all working fine.

I'll see if i can make a diagram of my system and post it for review/suggestions.

I have noticed that the pipe that feeds the troubled rad is hot at the boiler end, but near the radiator (still in the basement) it's cold(er). In addition to the weird main setup, could that pipe be pitched incorrectly causing the steam to condense out before reaching the rad? Would raising the radiator (and therefore rasing the radiator end of the pipe) help with the pitch, or is that not how to remedy such a problem?

jim_137

steam

Jason one simple step you can do is remove the radiator vent and start the system. Then see if steam exits the vent hole. If so the vent is the problem and bad or my be improperly sized. Caution - this can be dangerous(HOT STEAM)and messy, you should close the rad feed valve slowly to stop the steam ,then shut your system and reopen the feed valve.After doing this get back to us. Good Luck

Jason Lehr

Well, that is certainly a simple and elegant solution for troubleshooting the vent, eh? I'll let you know what i find!

Unknown

copper!?!

Copper piping on steam supply is a big no no... Piped improperly will gives ya nothing but headaches.. Wondering how's the boiler is piped? Any pictures of it?

Unknown

copper!?!

Copper piping on steam supply is a big no no... Piped improperly will gives ya nothing but headaches.. Wondering how's the boiler is piped? Any pictures of it?

Daniel_3

When the boiler is at about full cut-out pressure (basically when it's about to be shut-off by the thermostat)you will hear loud banging(water hammer) which you do have to an extent as you have said if the pipe is pitched incorrectly and water is indeed caught in the pipe. I once had to remove nice tongue and groove maple plus the subfloor to raise a stuck riser about 4 inches to let the water drain and the radiator to heat up. A blockage could exist(unlikely since there is heat to the radiator)and/or the radiator could have a lot of scale(rust droppings that is also unlikely). My best guess from what is shown and what has been shared is that the pipe diameter is too small, it shouldn't be copper but black iron and black pipe, and all the piping should be redone. Whoever did the piping piped it as if it were carrying water only. Call a pro from the "find a professional link" to have all the piping looked at and an estimate done to replace it all the right way. You could try the vent route as I and other have discussed and it could solve you problem but I would suggest the former since the vent route is just a quick fix but should be done even if all the piping were correct. Get the books from here and see for yourself how much of a lost art this all really is. Post pictures of the cold rad and the rad that heats on the other side of the wall.

Jason Lehr

ok, more pics

OK, here are some pics. I'm going to make several posts each with one attachment with description.

Before i do that - i took out the vent on the troubled radiator, and i get heat, but nothing comes out of the vent hole, and only the first 6 out of 16 cells get hot.

Jason Lehr

This is the boiler. Return pipes are blue, water feed is green and the main head is red. Pipe labeled 1 is a good radiator across the wall from the bad radiator. Pipe 2 is the feed for the bad radiator

Jason Lehr

Another boiler pic. Again, blue is return, red is the main.

Note the fantastic location of the relief valve. And oh yeah, the whole boiler faces the wall, so the sight vial and pressuretrol are really hard to see.

Jason Lehr

These are below the floor, about 10 feet away from the radiators. 1 is the feed for the good radiator, 2 is the feed for the bad radiator.

Jason Lehr

Here are the radiators. 1 is the good radiator, 2 is the bad radiator.

Unknown

those pictures help

Another good boiler brand installed bad by kuckleheads..... I see the problem radiator been relocated as the floor joint been cut out way too much... Time for a real boiler Pros to help you with the proper repipings ... Where are you located?

Dan_29

radiator not heating

From the picture of your boiler, I suspect is is a Weil McLain EG series. I have a similar boiler. I have learned a few things by frequenting this page and reading Dan's book.

My observations are:

-your main riser appears to be too small-- most eg series are 2 1/2 or 3 inch risers.

-your equalizer pipe is wrongly located and piped

-copper is a no no near the boiler--the solder cannot take the stresses that steam inflicts upon it

- your system mostly works despite being wrongly piped--yet another steam system mystery
-I suspect that the steam line that serves the problem radiator does not have a line vent on it

Suggestions:

Read the Lost Art of Steam Heating

Call a pro to re-pipe the near boiler piping correctly in black pipe-also find out if your boiler is properly sized for your radaitors

Check out the Gorton steam air venting website for line vents and an explanation of venting. If you do not have adustable vents on all radiators --get some.

I had a new boiler installed by a pro and solved many problems knuckelheads had created. Attached are photos of the knucklehead old install and pro new install.

Dan