What's wrong with this picture?

HeatingHelp

What's wrong with this picture?

See the remote thermostat sitting on top of the hot radiator? The folks in that office wondered why they couldn't seem to get comfortable.

Read the full story here

LarryK

Can you talk about TRVs and one pipe steam? I have a bedroom room that bakes in the sun and freezes at night with a massive radiator in front of a bay window. When the boiler comes on in the morning the temp overshoots and we have to kick off the covers. I got a TRV for the air vent and it didn't seem to have much effect, so I got a remote sensor for it and mounted it to the wall by the air valve. Exterior wall by the window. No effect. Finally I moved the sensor to the end of the radiator by the steam pipe where it heats up first. Now it works pretty well and the covers stay on all night until we get up.

Rich_L

You paint amazing pictures with your words, Dan! THANK YOU for sharing so much of your valuable knowledge and experience, even with 20 years in the trade, I'm still learning! (And I had to look up "verbosity" LOL)

nicholas bonham-carter

It sounds like your system is using a nighttime setback, which will not save on gas consumption, but merely cause temperature overshoot, which your TRV has been able to cope with.
Start a new thread for any future problems.
If this is an apartment building, check with management for:
1. The method of control-ie. thermostat, Heatimer control, etc.
2. The system pressure-lower is better, (under 1 psi). I heat 55 rads with a couple of ounces.—NBC

EricShelsy

Yeah Dan very helpful. With ADD and Dyslexia I will read this at least two more times. Thank you for sharing your knowledge. Great stuff.

DanHolohan

Thanks, guys.

skyenglish

Hello Dan, Nice write up... Thanks for sharing. I am looking to replace all 16 radiator valves in my home with TRV's. But, how do I determine if I should purchase large capacity valves or regular capacity ones? I installed a new boiler... going with the same model and size as the original" DunKirk Boiler Input BTU 299000; Max Relief valve cap. 245 MBH or LBS/HR; Steam PSI 15; Water PSI 30; Max Gax Pressure 14 in W.C.; Min Gas Pressure 5 in W.C.
Manifold Pressure 3.5 in W.C."
Also, should the old trapes be replaced, if so, should I go with Thermostatic ones?

Thanks for your time
Sky

Jamie Hall

Wow. We seem to have at least two unrelated threads here, folks. @skyenglish and @LarryK , you'd both be much better off with separate threads.

First, though, @LarryK . A TRV (vent) on a one pipe system will do absolutely nothing to stop the heating on a radiator which has already started. It can only keep the radiator from heating -- or heating more -- if the boiler turns off and the pressure drops to zero at least briefly. In your situation, this isn't going to happen.

And @skyenglish -- I'm not sure whether you have a one pipe or a two pipe system; your mention of traps suggests a two pipe system. In which case, you need Thermostatic Regulator VALVES, not vents. Different beast. You also don't mention whether the boiler is correctly sized to the rest of the system (that's a pretty big boiler for a residence, but not unheard of). In any event, the system must be well balanced to begin with, particularly on two pipe systems with adequate main venting on the dry returns or on a one pipe system on the mains and then, the operating pressure must be kept reasonable (less than 1 1/2 pounds on one pipe and most two pipe, much less on some types of two pipe), and, on both systems the output from the radiators reasonably balanced to begin with (different vent sizes for one pipe, adjusting the input valves on two pipe). Only then can you think about using TRVs (vents for one pipe, valves for two) to adjust individual spaces for occasional desires (they can both lower the space temperature, neither can raise it) -- and only with great caution, as excessive use of them will result in the boiler short cycling very badly and wasing a lot of energy.

skyenglish

@Jamie Hall, Thanks for your response... This system has been installed for over 38 years and it's a two-pipe system. I'm sure it works as it was designed because it worked great before the boiler reached end of life. I just wanted to change to TRVs and questioned if I needed high-capacity TRVs or not???
I will create a separate post.
Thanks