Recommendation for thermostat and placement

amakro15

I currently have a Honeywell Pro th4110d1007 thermostat. It is set for steam heat. The thermostats inside temp reading is always off by about 2 degrees. It is on an inside wall on main floor of home. The thermostat is not close to any radiators or kitchen. I have a 2 story colonial. The 2nd floor is always cooler than the main floor by at least 3-4 degrees. All radiators have vent rite #1’s, and mains are well vented with big mouths and G2’s

My questions are:
1) Which thermostats would you recommend for steam? Do wifi thermostats work well with steam systems? Or is the more basic thermostat a better choice?

2) Would moving the thermostat to 2nd floor be a better placement?

Jamie Hall

Moving the thermostat -- or changing to a different one -- won't change the balance between the floors. Have you tried -- assuming you want to change -- slowing the vents on the lower floor?

The thermostat you have is a good one. Some are fancier, some less so. Adding wi-fi to a thermostat doesn't make it better or worse; it just means that you can hook it into your local wi-fi, if you want to or need to. Be aware that some of the heavily advertised and marketed ;thermostats for wi-fi have proven to be somewhat problematic with steam systems.

amakro15

I have lowered my main floor radiators vents set to 5 and upstairs radiator vents set to 6-7. I’ve tried to set main floor lower than 5 but radiators won’t really get hot. Upstairs some radiators will get hot on top and stay cold on bottom and middle. 

Does slowing radiator venting increase system pressure? 

The thermostat will read let’s say 74 inside but it’s really 71-72 where thermostat is placed. I will lower temp to 70 and a few minutes later the temp reading will drop to 70 and kick heat on. But then thermostat reading will jump back to 74 a few mins later before steam even gets to radiators. 

I do think the system could be a bit better balanced somehow but I still feel that something is up with the temp swing with thermostat.

bburd

Any hole in the wall behind the thermostat (like where the wire comes in) must be sealed airtight. Air currents from inside the wall can cause incorrect thermostat readings and/or erratic operation.

Is there a steam pipe in the wall behind the thermostat?

amakro15

@bburd there is a main that runs in basement right under where thermostat is but main is insulated and thermostat is about 6ft or so above the main. Would moving thermostat over a few feet on wall make a difference?

bburd

Probably not, unless there is a steam riser inside the wall. But definitely check to make sure any holes behind the thermostat are sealed.

Some houses with large boilers or uninsulated steam pipes have very warm basements, which can cause a warm draft up the wall behind the thermostat.