Radiator Not Hot - Is This Ok?

rhw

Radiator, which is last on main, is not heating up. I have tried different vents but none make a difference. It appears that with no vent the unit gets somewhat warm. Is it ok to operate without a vent for the time being? Need this radiator to produce some heat as it is in the same area as the thermostat for the whole house. Thanks.

Fred

You don't want to run the boiler with the vent off of the radiaator. At some point, the boiler may run long enough to get steam to that radiator and someone could get scalded from the steam or it could vent steam during the night and the water would ruin a lot of stuff before you knew what was going on.

Paul S_3

has something changed like a thermostat changed? maybe not set for steam?are you sure the supply valve is open? did someone shut it recently and tried to reopen it? sometimes they do not reopen.. with the vent off for the time being while you test the radiator should get hot..but like FRED said it cannot stay like that for anytime other than a test to see if it gets hot....what kind of system is this 1 or 2 pipe steam? you may need more main venting .. has this always been a problem or is this new?

rhw

One pipe system. How can I tell if the supply valve is not stuck closed? The valve is in the full open position. Unfortunately no main vents. This morning several more of the radiators are cold. The main pipes in the basement are all hot. Out of nine radiators only 3 are functioning. The boiler is running constantly and most of the house is freezing. I am at a loss.

Yesterday all radiators had some heat except the one mentioned above. I have been swapping radiator vents but to no avail.

Paul S_3

Is this a new problem....has anything changed?......maybe the pigtail is clogged on pressuretrol?

rhw

Just removed a Hoffman 1A from a radiator that has always had heat, except this morning, and the radiator is getting warm. The only difference from yesterday till today is that we opened the valve in a guest room radiator that has been closed for several years. That is one of the three that is heating (lucky guests!).

Sorry but do not understand about how cleaning the pigtail would help? All the mains are very hot. If pigtail is clogged and possibly affecting steam to the risers how do I unclog it? Thanks again.

KC_Jones

rhw said:

The only difference from yesterday till today is that we opened the valve in a guest room radiator that has been closed for several years. That is one of the three that is heating (lucky guests!).

And that indeed can change everything. You may need to re-balance all or part of your system now. This is one reason many of us on here tell people to never close off radiators on a steam system. What size vent is on the radiator that you just opened? I just read one of your other posts. You have no main venting correct? That can certainly contribute to the problem especially if this is the last rad on the line. You can't really balance the system properly until the main venting is correct.

rhw

The radiator just opened has a Maid O Mist. The radiator at the end of the main, that I need to get heated, it affects the thermostat, has a new Hoffman 40.

Just checked the pipe off the main that goes to the riser of this last radiator and it is starting to get hot (about halfway so far) with the radiator vent off.

KC - should/can mains vents be put on during the heating season? Is this job only for a skilled steam plumber?

gennady

Just up-fire boiler to compensate for additional load. check against boiler rating, so you will not over-fire boiler.

KC_Jones

rhw said:

KC - should/can mains vents be put on during the heating season? Is this job only for a skilled steam plumber?

Since I don't know your skill set I can't say for sure. On my system in my house I would/could do it during the season. A pro should be able to do it during the season. A Hoffman 40 is a fairly small vent. What you could do as a bandaid until you can get main venting is to put a larger vent on that rad to get through the season.

rhw

I have a Gorton C & 6. Either of these better than the Hoffman for now?

KC_Jones

If you already have them all you have to lose is the time to change a vent. Either of those is bigger than what you have currently so try it and see. Again this should be considered a temporary fix to get some heat and not a permanent solution. Sometimes we gotta do what we gotta do.

rhw

Thanks. The radiator is now almost fully heated with no vent. I will now put the Gorton 6 on that radiator and make sure all of the radiators throughout the house are fully opened.

Is there a video somewhere showing how to install main vents? I am not afraid to try fixing most things (except electric & gas). I recently drilled a radiator hole to put in an insert for a threading issue. But adding a tree and vents to the main may be beyond my capabilities.

Thanks again and again!

Fred

Do you see any tapping with plugs in them anywhere on the Main, after the last radiator run out? If so, and if you can get the plug out, that's an ideal place to put your main vents and makes the job fairly simple. If you have more than one main, you need to do the same thing on each. Also, you did not mention what thermostat you have. It is very important that the thermostat be set for steam. They come with a factory default set for forced air at 5 cycles per hour. It needs to be set for 1 cycle per hour, for steam. At the factory default, the boiler won't run long enough to push steam out through the system. It will keep the mains hot and maybe the closest radiators but the cycles are just too short, especially with no main venting. To answer you question about the clogged pigtail, if it is clogged, it will cause the boiler to cut-out on pressure in 2 or 3 minute increments. Not going to be very effective at heating the radiators.

rhw

Unfortunately no plugs on the mains. So I am guessing that an install of main vents would require drilling the main piping? Better leave that to the pros?

The boiler is running constantly as the thermostat (see picture) is in a room that is not warming because of the radiator. However I have now closed the valves on 2 of the radiators on the same main and this one is now heating up...again.

The mains are uninsulated and I thought of going out now and buying to install today if that would help?

I want to thank you all for helping as I have been running around the house trying all sorts of solutions. I may let the radiator heat up and warm the thermostat room before opening the valves on the others as those rooms are currently not being used. Almost at the end of my rope.

rhw

Thanks HatGuy - but if this was for me it appears way above my level of knowledge.

All I know is that once the temperature level of indicated heat is reached on the thermostat the boiler will shut down. I am trying to get my system balanced so that the end of the line radiator heats the room where the thermostat i,s so it shuts the boiler as intended.

Right now the only way I get there, without main vents and perhaps insulation (if that would help) is to turn off several radiators enabling this last radiator to heat the room. When I open up the other radiators however, the situation reverses.

rhw

No tappings in pipes that I see. So would I drill these with a pipe tap and then install the vents? Do the pipes really need to be removed first? Ugh!

Also are saying that with my system, as poorly as it is balanced and vented now, that as soon as the boiler run is finished everything will go out of whack again? My wife's gonna' kill me!

rhw

Hopefully I can get someone to vent the mains soon. Radiator in room with thermostat going cold fast. Looks like we will be hot in 2nd floor rooms while 1st floor freezes.

neilc

op,
I think you need to insulate those basement mains,
your loosing too much steam energy down there.
this might get you heat up to the rads,
that and add the main venting.

neilc

and if you could slow down your 2nd floor venting that might free up some energy for the 1st floor.
But main vents, main vents, main vents

rhw

Closed valves on 2 of the 4 radiators on the main that supplies steam to the radiator in question. Now at least the radiator in the room w/ the thermostat is heating and pushing up the temperture in that room so that the thermostat can do its job. It is a little cooler in the rooms where the valves are closed but since they are upper rooms not so bad. Thanks everyone for your help. Still looking for some sort of tutorial on how to install main vents.

JimmyNJ

Another thing to look for is to make sure that the problem radiator has a slight pitch back to the supply pipe. If there is no pitch, water will collect in the radiator and prevent it from heating properly. Good luck.