TRV for recessed convector

aat879

I have one-pipe steam with convectors recessed into the walls. I just got a new boiler and am looking forward to the heating season to see how well the system balances and, if it isn't, will start with strategic venting. However, my living room has four convectors that are all first on the main runs, so that room heats up a little more quickly and, because there are four of them, the room gets a little too toasty before the tstat is satisfied.

If the venting doesn't quite do the trick, I would like to install TRVs on one or more of the living room convectors. However, because they are recessed in the walls, there isn't room for one of the TRVs with a 90-degree stem that would screw into a radiator from the side. Are there any options for a TRV on my convectors?

I'm hoping perhaps to find one small enough to fit and then hook up to a remote sensor mounted on the wall, but I can't find anything so far. Any ideas? In any case, whatever screws in to the air vent needs to be straight and fairly narrow. Take a look at the attached pictures to see what I'm dealing with. Right now I have Hoffman 41/43s in all my convectors.

gfrbrookline

Stay away from TRV's on 1 pipe steam. I had 1 unit in my building that insisted on using them because she was too hot and wouldn't listen the slower vents. When she installed them she complained about her unit being too cold because they shut off prior the the rest of the building heating up. Since the rest of the building continued to heat after her TRV's shut her radiators off, her unit started to cool while the rest of the building was heating up so her unit became colder than the rest of the building. The TRV's also caused slight water hammering in the system. If your room is over heating try Hoffman 40 or Gorton #4 vents to slow them down before looking at TRV's.
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mattmia2

You could use this with an angle vent and a remote head:
https://www.supplyhouse.com/Danfoss-013G0140-Thermostatic-Rad-Valve-w-Vac-Breaker-1-Pipe-Steam-5551000-p

Might need to use a union or remove the offset or both to be able to connect it to your convectors

gfrbrookline

This was the TRV my unit owner used with problematic results.

mattmia2

they should work with the understanding that TRVs aren't perfect on 1 pipe steam. they won't stop the heat once it has started, they can only stop the radiator from heating if they are closed at the beginning of a cycle, they can't stop it mid cycle.

i wonder if this caused your user to turn them down so far that they never opened.

If these are close to the boiler and overheating, try adding more main venting to get the mains filled more quickly.

EBEBRATT-Ed

@aat879

try shutting off 1 convector

aat879

Thanks so much. I may indeed just try starting with shutting one of the convector off. I'm sure the original installers in the 1930s new what they were doing, but it does seem that this room has too many radiators. Three under exterior windows, which I would keep on, and one on an interior wall, and then a small one in the entryway that the living room opens up to. The one on the interior wall seems unnecessary and would have served best elsewhere (like at on the upper landing of the stairway, where there's a big window but no radiator).

I'll start by shutting that one off. If that doesn't work, I'll be trying additional main venting, but that would require the pros to come and takes a bit of time. A TRV is something I'm considering for the meanwhile.

gfrbrookline

Not sure if you have the swing room for it but Gorton make a straight No. 4 that will slow those convectors down nicely. Shutting radiators off can cause new issues/imbalances elsewhere.