Steam radiators only partly heating - help !

NYCer

Hi everyone,

My contractor recently installed three Governale Free cast iron radiators and only one of them consistently heats up all the way. Two of them are the same size (12 coils) and the third one is significantly bigger (26 coils) - apologies if that's not the right term. One of the smaller ones and the larger one only get partly warm, and usually closer to the top of the rad while the bottoms stay cold.

We live in a steam-powered building in Brooklyn and nobody else on our line is having heat issues. The risers get warm, as do all three supply valves feeding the rads from the floor. We called in a plumber who noted that:

1) Air vents are too high on all three rads. The contractor used the bushing at the top of the rad, on the opposite side of the supply, when they should've used the tapping about 1/3rd of the way up the rad. The current air vents that are on all three are Groton C's.

2) Apparently two of the three rads are installed "backwards". I am not sure what that means since the rads looks exactly the side on both ends to my untrained eye, but perhaps I missed something. Interestingly, the only rad that works was also called out by the plumber as having been installed "backwards".

3) None of the rads are pitched enough towards the supply.

While the plumbers were around, we got the super to put the boiler into bypass mode so that it was constantly pumping steam, and lo and behold, all three rads were heating up like you would expect. That debunked my theory that the two non-functioning rads were problematic.

Given the above observations, I'm still at a loss in understanding what to do. It certainly sounds like the venting location is an issue based on what I have read on here, however I don't understand how a rad can be installed backwards and what, if anything, that has to do with the fact that two of the rads are not heating up like the other one is .

Please help, and thanks in advance!

ratio

A few pics of the radiators would help.

Also, are you having temperature/comfort issues? It's not necessary for a steam radiator to be fully hot for it to adequately heat a space—and it sounds like you might have some big ones there!

Fred

Post a picture of the radiators so we can see what is going on. Based on what you've said, if the vents are on the top of the radiators, that may be your problem. A second possibility is that the vents are too fast and steam is racing across the rad and closing the vent, trapping air in the radiators and preventing them from heating evenly. In both cases, misplaced vents and vents that are too fast will create this problem
Keep in mind that radiators don't always heat all the way across, depending on how long the boiler runs to bring the thermostat up to set point but they should heat evenly, top to bottom on each section. Not necessarily all sections from one end of the radiator to the other end.

NYCer

Here're three photos of the biggest rad in the living room. The other two are exactly the same, except smaller.

Pic 1

Pic 2

Pic 3

I still don't see how these could have been installed 'backwards' - any idea?

@ratio there were a few nights last week where it was quite cold outside and the boiler was pumping steam, but the rads stayed cold. Unfortunately one of the rads that isn't working is in my young child's room, so that's where the main concern is.

@Fred , you're right, our boiler only stays on for 15 minutes at a time every hour if the thermostat warrants it. Even in this case though, the one in my room works just fine and is warm all the way through. It's vented the exact same way as this one, via the top bushing.

Intplm.

Is there a tapping 2/3 up on the side of the rad that the valve is on? (it looks like there is but can't be 100% sure from the pic.)That might be the explanation for the backwards installation comment. If so, turn the rad around, swop the plug for the valve and install the vent 2/3 up. Might be all that you need to do.
From the picture, the rad seems to be pitched fine.

ChrisJ

Are the rooms cold?

NYCer

Intplm. said:

Is there a tapping 2/3 up on the side of the rad that the valve is on? (it looks like there is but can't be 100% sure from the pic.)That might be the explanation for the backwards installation comment. If so, turn the rad around, swop the plug for the valve and install the vent 2/3 up. Might be all that you need to do.
From the picture, the rad seems to be pitched fine.

There's a tapping on either side of the rad that's about a 1/3rd of the way up the rad. The one that is currently on the supply side does appear to have less of a 'filling' so that an air vent could be put in. See this photo:

Tapping on supply side

The same tapping on the other side of the radiator looks like this:

Tapping on the other side

Do these photos indicate that the radiator should be flipped around so that the air vent can be installed on the lower, and correct, tapping?

NYCer

ChrisJ said:

Are the rooms cold?

Because the temperature has been in the 60s the last couple of days, no. However, they were much cooler last week!

Danny Scully

The vents are installed in the wrong location. The radiators can either be reversed to accommodate this of the radiators can be left as is and drilled/tapped for proper vent locations. Period. Stop.

NYCer

Danny Scully said:

The vents are installed in the wrong location. The radiators can either be reversed to accommodate this of the radiators can be left as is and drilled/tapped for proper vent locations. Period. Stop.

Thank you ! So are you saying that with option B, leaving the rads as is, that the vent can still be installed in the right place but the rad just needs to be tapped to accommodate?

I've also just checked the rad that the plumber said was installed correctly (i.e. not backwards), and that one does have the more obvious tapping on the opposite side of the supply. However, it's also one that still stays cold. interestingly, the one in my room that is installed backwards is still vented incorrectly, but is the only one that works.

I'm struggling to identify a common denominator amongst all three rads that can be used to explain the situation. It might just be that putting the air vents where they belong will solve, but I would personally just like to understand what's causing all of this craziness!

Intplm.

NYCer said:

Intplm. said:

Is there a tapping 2/3 up on the side of the rad that the valve is on? (it looks like there is but can't be 100% sure from the pic.)That might be the explanation for the backwards installation comment. If so, turn the rad around, swop the plug for the valve and install the vent 2/3 up. Might be all that you need to do.
From the picture, the rad seems to be pitched fine.

There's a tapping on either side of the rad that's about a 1/3rd of the way up the rad. The one that is currently on the supply side does appear to have less of a 'filling' so that an air vent could be put in. See this photo:

Tapping on supply side

The same tapping on the other side of the radiator looks like this:

Tapping on the other side

Do these photos indicate that the radiator should be flipped around so that the air vent can be installed on the lower, and correct, tapping?

"Flipped around?" Yes that is what I would do. Turn the rad off, let it cool down. Get some help. Put something under the feet of the rad to help spin it without scratching the floor. (I use a old carpet remnant turned upside down to do this.) Swop the plug for the valve spud. Swop the vent for the countersunk plug on the valve side, install the vent where the countersunk plug is now.
In other words, just swop all from one side to the other.
That should make the rad work better.

Intplm.

@NYCer After re-reading the comments on your post. I would suggest getting a competent service company in there to diagnose your problem first hand.
From here one cannot tell if you have proper venting, plugged vents or correct piping serving the radiators. Your radiators only partially heating compared to one from another doesn't make sense to me from here.
Those rads look brand new. Are they? Or are they refurbished?

Where did the rads come from and how were they checked for proper operation before being installed in your place?

And are you SURE that they stay cold?
Do you have a obstruction in one or more of these rads that make them stay cold?

I would get a second opinion from a reputable company that can physically look over the situation.

Intplm.

And....not for nothing. Make sure the valves are turned on all the way.

Fred

The tapping on either side of that radiator can be used. Whichever you choose, it has to be drilled and tapped. They are in the right location. I don't know that it's worth turning the entire radiator, trying to get the spud out without damaging it and moving it to the other side.

The radiator that works probably works because it is either closer to the boiler and starts to get steam first and while all the other vents are still open so the steam velocity is lower making for an opportunity for that radiator to fill better OR, once the other radiator vents close, enough pressure builds to over ride the vent . Do you see any steam venting from the working radiator? When you say that radiator works well, have you felt it, top and bottom to see if it is actually hot on the top and the bottom or are you assuming because the room is comfortable that it works as it was designed to work? Is there a larger vent on that radiator that may allow more air to escape before the vent closes?

JUGHNE

Spuds may be easy as new as they are.
I would try the spuds and opposite pipe plug first and if a no go, then drill the boss on the other end.

NYCer

> @Intplm. said:
> @NYCer After re-reading the comments on your post. I would suggest getting a competent service company in there to diagnose your problem first hand.
> From here one cannot tell if you have proper venting, plugged vents or correct piping serving the radiators. Your radiators only partially heating compared to one from another doesn't make sense to me from here.
> Those rads look brand new. Are they? Or are they refurbished?
>
> Where did the rads come from and how were they checked for proper operation before being installed in your place?
>
> And are you SURE that they stay cold?
> Do you have a obstruction in one or more of these rads that make them stay cold?
>
> I would get a second opinion from a reputable company that can physically look over the situation.

Thanks for the comment 👍. I've already got one
> @Intplm. said:
> @NYCer After re-reading the comments on your post. I would suggest getting a competent service company in there to diagnose your problem first hand.
> From here one cannot tell if you have proper venting, plugged vents or correct piping serving the radiators. Your radiators only partially heating compared to one from another doesn't make sense to me from here.
> Those rads look brand new. Are they? Or are they refurbished?
>
> Where did the rads come from and how were they checked for proper operation before being installed in your place?
>
> And are you SURE that they stay cold?
> Do you have a obstruction in one or more of these rads that make them stay cold?
>
> I would get a second opinion from a reputable company that can physically look over the situation.

My contractor sourced all three rads from the same local, well known plumbing supply store. I cannot say if they were brand new or refurbed, but I think you're going where I was initially going with this, in that my thinking was that the rads were defective somehow.

That's when we got the super to bypass the thermometer so that steam was constantly being generated for an hour, and in that situation, the two remaining rads warmed up, top and bottom, all throughout. That pretty much invalidated my theory that the rads were not working.

During a regular day, the two rads get warm on only the first one or two coils, and usually only at the top and not the bottom.

I'd love to get another opinion, but it is getting costly as each place charges me a fee to come out and take a look, plus an additional fee if I wanted them to do any further work. I really do feel like it's something relatively minor, so came on here to solicit some further advice

NYCer

> @Fred said:
> The tapping on either side of that radiator can be used. Whichever you choose, it has to be drilled and tapped. They are in the right location. I don't know that it's worth turning the entire radiator, trying to get the spud out without damaging it and moving it to the other side.
>
> The radiator that works probably works because it is either closer to the boiler and starts to get steam first and while all the other vents are still open so the steam velocity is lower making for an opportunity for that radiator to fill better OR, once the other radiator vents close, enough pressure builds to over ride the vent . Do you see any steam venting from the working radiator? When you say that radiator works well, have you felt it, top and bottom to see if it is actually hot on the top and the bottom or are you assuming because the room is comfortable that it works as it was designed to work? Is there a larger vent on that radiator that may allow more air to escape before the vent closes?

Yes, the one that works well is always hot at the top and bottom, across the entire radiator. I've gone up and touched it on multiple occasions to make sure! All three rads have Gorton C vents in the same location (at the top, opposite end from supply). I haven't seen any steam vent from either, but I do hear air escaping all three rads from time to time.

Interesting that you say that the vents are in the right place, or, did you mean that the tappings are in the right place but the vent needs to be moved to the lower one?

Fred

@NYCer , correct, I meant to say the tappings are in the right place but the vents need to be moved! My bad.

neilc

You need to get the vents dropped down to the lower bosses, which need to be drilled and tapped, fairly easy thing to do, and why you're being told the rads are backwards, there is a removable plug on the other(valve) end, if the installer knew steam they would have used that plugged boss and the opposite steam inlet,
you were asked if the apartment was cold or comfortable, if you're good then do nothing, I'm assuming that since you're here asking there are comfort issues you're looking to solve.

NYCer

> @Intplm. said:
> And....not for nothing. Make sure the valves are turned on all the way.

I hear you - first thing I checked and they're always on all the way

Intplm.

Look closely. It looks to me like only one side has a threaded tap for the vent. That would be the countersunk plug viewed above the valve? The opposite side doesn't look like it has that plug installed. That's why I suggest flipping everything, (pending on if its a DIY and your comfort level of drill and tapping.) Drill and tap if you prefer. Me, I would turn the rads.
Get that part of your heat corrected, than look to other problems as they come up.

Hope this helps.

NYCer

> @Intplm. said:
> Look closely. It looks to me like only one side has a threaded tap for the vent. That would be the countersunk plug viewed above the valve? The opposite side doesn't look like it has that plug installed. That's why I suggest flipping everything, (pending on if its a DIY and your comfort level of drill and tapping.) Drill and tap if you prefer. Me, I would turn the rads.
> Get that part of your heat corrected, than look to other problems as they come up.
>
> Hope this helps.

Yes you're absolutely right; there is no threading on the other side, and now it makes sense why the plumber suggested flipping the radiators around in the first place.

Sounds like that's what needs to be done first, followed by moving the air vents down to the proper spot.

I hope this takes care of the issue! I'm by no means an expert, but the fact that most people so far have recommended this course of action is promising!

nicholas bonham-carter

I would also check downstairs to see if there is adequate main venting.
The radiator air vents can only handle the air escaping from the radiator, and it’s riser, whereas the main vents have the capacity to clear out the air from the boiler steam chest, and mains.—NBC

Intplm.

@NYCer Any update on this?