two pipe steam house radiator troubleshooting

KellyAnn

Only half of each of my two pipe steam house radiators gets hot. There is no air valve. what should I do? The house was built in the 1800's

Grallert

Are you sure it's steam? There would be a steam trap on the end opposite the valve end. That aside sometime a radiator will not heat all the way across. If the thermostat is satisfied the radiator may only heat partially. Is the room comfortable?

KellyAnn

Yes, its steam. the room is not getting to the set temp.

KellyAnn

I have an older model of this weil-mclain boiler. https://www.weil-mclain.com/products/eg-gas-boiler

KC_Jones

Are you saying specific rooms are not reaching temp, or the whole house is not reaching temp?

If the whole house is not reaching temp, then the thermostat is calling continuously, the boiler never stops and the whole house is cold. This would be difficult, but not impossible to believe. The answer will help us give you some direction.

KellyAnn

the house has not dropped below 60F and the boil turns off and on. I have the Thermostat set to 68F

KellyAnn

I'm trying to find a new Thermostat for heat only but its hard.

KC_Jones

So the whole house isn't reaching set point. If the boiler is shutting off and you aren't at temp, that would be one place to start. Would want to figure out what is shutting the boiler off, sometimes the thermostat has the incorrect settings and can cause strange performance of the system. What type of thermostat do you have?

If it's the pressuretrol shutting it down, that could be a function of an oversized boiler and just have to deal with it.

So the next is the rads not heating all the way across. On 2 pipe, many times the valve has an adjustable control for how much steam you can get, if it's turned down you may not get enough steam for your comfort level. Check the valves and see what they are set to and open them up more if possible.

Some pictures of your boiler an piping could help, that would allow assessment of if the piping could be causing issues.

Also what is the main venting in the basement like?

KellyAnn said:

I'm trying to find a new Thermostat for heat only but its hard.

Why do you think you need a heat only thermostat?

KellyAnn

the Thermostat is a Honeywell from the 60's. I will add better photos when I get home from work.

w

Jamie Hall

Nothing inherently wrong with that thermostat -- except that it may be out of calibration. To make sure it isn't the thermostat, next time you have a call for heat wait until the boiler stops -- and crank the thermostat up five degree or so. If it is the thermostat shutting the system off, that should fire it back up again -- and the problem is the thermostat is out of calibration. It happens, and a new thermostat may help.

If not, you need to find out what is shutting the boiler off. There are at least two controls on the boiler which might be, and there may be more. One is a pressuretrol or vapourstat, which reacts to pressure, and the other is a low water cutoff, which reacts to water level in the boiler. If you could take a picture of the boiler (better yet, several!) we can point you to which control is which.

As to is it steam -- yes, in most cases there would be a trap on the outlet of each radiator, as @Grallert said. However on looking at the radiator photo (I can't enlarge it) I am a little suspicious that that may be a vapour type vavle on the inlet -- in which case it is quite possible that there isn't a trap on the outlet -- just a patented gizmo which may not be at all obvious. But, having said that, if it is indeed a vapour system, it must be run on very low pressure -- a few ounces at most -- which may require a much better pressure control than you have. If it is run on high pressure (say a pound or more) it is quite possible that steam is blowing by one or more radiators, which will keep the system from working well -- if at all.

JUGHNE

I came across a tstat just like that and it had a shorted heat anticipator . When set to normal temp it would just cycle the boiler on and off.
If you turn it all the way up and see if the boiler stays on as Jamie says.
There is an adjustment under the cover, looks like an arrow on a numbered scale. You want it towards the word "longer".

KellyAnn

More photos

JUGHNE

KellyAnn, are you new to this house or is this a new problem?

Could we see the other side of the boiler....looking for the grey box control with the curled pigtail pipe under it, sight glass and any other pipes connected maybe at floor level or coming up thru the floor. Not too close....your other boiler pictures are at the good distance.

KellyAnn

We just moved in. The psi never moves past 1.

KC_Jones

Need to locate your main venting in the basement. Your pressurtrol (grey box on boiler) is set far too high, and I suspect a lack of proper main venting which will slow the steam down and could be, in part, the cause of your issues.

Need to find the end of the mains and end of any dry return piping to look for main vents. Main vent is a device that will come out the top of the steam piping in the basement. I think I see a place one might be in one of the boiler pics, but it’s too dark to be sure.

JUGHNE

That was my guess that you are new home owners, congratulations!

First, order the book above in the store....."We Got Steam Heat".
Just what you need, written for home owners.

The thermostat is suspicious if this never gets over 1 PSI on the gauge. But then the gauge is also suspicious.
Your pressure control would probably give you 4-7 PSI.
That is the only way this would have heated at all.
There seem to be no way for the air to leave the system so that steam could enter, so the higher pressure would compress the air partway across the radiator. Having the tstat call continuously would keep the boiler on and raise the pressure....compressing more of the air. This is not what you want.....it costs money to compress air...the steam pressure should just push it out of the system thru air vents in the basement.

There would usually be air vents at the end of the steam mains or at the end of the dry returns which are those smaller black pipes connected to the 2" galvanized riser. Perhaps there are air vents at the end of the larger, insulated steam main. Look for them or a tee that has a plug in it.

If you go to the Weil Mclain site you mentioned above and down load the boiler manual ( I would suggest printing the entire document), but first look at page 17.....steam boiler piping.


You have (or had) some form of steam vapor system. But some knucklehead has bastardized it into something not usually seen here. It looks like you have/had orificed inlet valves. Maybe no trap on the outlet. You could have orifices installed in the inlet valves if you have no steam traps. This would allow the rad to heat 80% across. This usually heats the room enough if thing operate normally.

Where are you located?

JUGHNE

What is on the top of the large galvanized pipe/tee?
And also in the top tee of the steam riser coming out of the boiler.
And where does the water feeder (small copper pipe) connect to the boiler?
Could we get a picture of those?

Steamhead

JUGHNE said:

What is on the top of the large galvanized pipe/tee?

That's either an air vent or an ancient safety valve.

@KellyAnn , where are you located?

KellyAnn

We are in NJ.

KellyAnn

What should I do to get heat in all of the rooms in the house?

KellyAnn

Water inlet

clammy

Looks like your pressuretrol setting is to high .also looks like your system may need some T L C . You should make sure the hand valve is open and also follow out your piping from the boiler to the radiator and see where the heat stops ,it may be as simple as a bad or cold trap . It looks like your main vent could use a update .where in nj you may need some who knows what there looking at to assist your repair peace and good luck clammy

Grallert

The first and easiest thing to do would be to lower the operating pressure. The grey box that says cut in. That scale should be down around .5 the screw on top, turn it counter clockwise to lower the pointer. if you remove the grey cover carefully you'll see a white knob. set that to 1. This should help a bit maybe a lot give it a try. Oh and before you do any of this, turn off the power to the boiler just to be safe. Should be a switch, looks like a light switch on the side of the boiler.

clammy

That’s not really where your water feed should be from the looks of it it was most likely installed by some one not to much knowledge when it come to steam . Do all your radiators have 2 pipes on them ? If so you may have a bad crossovers trap if you have them if not it most likely bad main vent aside from any other issues like to high a pressure causing your returns to get pressurized and stop any steam circulation . Be sure to get some one who is schooled in steam and has a clue how 2 pipe systems work and if they do not adjust your pressuretrol kindly ask them to leave there clueless Peace Nd good luck clammy

KC_Jones

@EzzyT or @Dave0176 would be good guys to call. Both top notch with steam.

I would suggest, by the looks of that vent, that you need a bunch more main venting to get the steam moving better. Also the pressure is way too high, which was probably some contractors idea to "fix" the problem, it is not.

JUGHNE

Your exhaust venting into the chimney looks a little strange also,
could you show us how the water heater and boiler are tied together?
You need one of the pros mentioned above......Ezzy or Dave.

clammy

This post should have been put in the steam section not radiant for a better response . peace and good luck clammy

Erin Holohan Haskell

Great point, @clammy. I've moved this post to Strictly Steam. Thanks!

acwagner

KellyAnn said:

What should I do to get heat in all of the rooms in the house?

You can hire someone, as others have mentioned.

Or, in many cases you can probably fix it yourself, if you're willing to learn and spend some time on this site. If you are new to steam heat, get a copy of "We Got Steam Heat" or "The Lost Art of Steam Heating". They are good reference to understand how your system is supposed to work.

If you end up hiring someone, these references will also help you understand if a contractor knows what they are talking about and will help the situation or make it worse.

nicholas bonham-carter

I see Clammy is in NJ as well.
KellyAnn, I would suggest getting someone in to have a look at your system, and at the same time, show you how to do the regular maintenance on it.
Most of the homeowners here have by necessity, and through love of steam, educated themselves beyond the knowledge of many so-called heating pros, who will never take the trouble to gain the skills needed to be real steam pros, and I sense that you will be soon part of our group.--NBC

Intplm.

Hang in there @KellyAnn , we can get this sorted out.
The first thing I would do is turn the pressure DOWN, to .5 as mentioned above.
That should help a lot.
The next thing is to get the thermostat working correctly.
If you cannot adjust the one you have now, replace it with a honeywell t87f . That is usually just a heat thermostat. It will say heat only. Round and have a 87 number in the description.
Looks like this one below.
When you put it in make sure the location is not above a radiator,
not getting direct sunlight or sun light reflected from a mirror, or the thermostat will be fooled thinking the temp in the conditioned space is satisfied. (It also sounds a little like what your system is currently reacting to.)
I would do these two things just for starters and see how the system reacts.

Hap_Hazzard

If that's a 60's era thermostat, it probably has a mercury switch, so if you replace it, you need to treat it as a hazardous waste. Personally, I'd be reluctant to get rid of it though, because mercury switches work a lot better than the newer mechanisms.

Harry_6

Vaporstat! Vaporstat! There's no way the system should be running on more than about 4 oz's. Also, who dumps ice-cold makeup water directly into a boiler? Yikes!

ajreed312

Correct me If I’m wrong, but if there are not traps on the radiators, shouldn’t the returns on the radiators all be piped to a wet return? At best have more venting. It just seems from the pictures that it can’t get the air out efficiency.

clammy

Not every 2 pipe has traps and or vents or even crossover traps some have none of it and just vacuum main vents and they work amazingly .just need dry steam ,insulation proper piping ,clean returns and a clean boiler really not much to ask for . From the looks it a vapor system from looking at the graduated hand valves .i ve seen them work w a standard pressuretroll assuming the boiler is not over sized and all the original valves are in place still . Who ever you call if they tell you that’s the way Steam is you got the wrong guys save some time and use some listed on this site before listening to some phvac who cannot correct the issue .For those who know steam could be a simple fix for those offer service contacts And such good luck ,recently replaced main vents on a system that a phvac company serviced for 3 years and about 3 out of 12 rads worked a few hours later every radiator was blazing hot .lesson is get a steam pro to look at your system and get it fixed period .a real steam pro will fix it and be done no service contract no bs sales .peace and good luck clammy