Using a White Rodger heat pump thermostat on steam boiler

thatguyinunit6

Hello,

I am an owner in a small 6- person condo in Beacon Hill Boston. I am looking into the heating and found that we have the wrong type of thermostat. Currently we have a White Rodgers 1F79-111, which is a heat pump thermostat on our very expensive boiler. I imagine this does not have the correct cycle and could actually damage the boiler, however, I wanted to ask you as I know many of you have expertise with steam heating. Do you know of any reason why someone might have installed a White and Rodger heat pump thermostat? Is this thermostat doing any damage?

I was thinking of replacing this with an Ecobee or a similar smart thermostat that I can set with some logic to control. I have a Honeywell Lyric T5 would this work/be safer for our boiler than what is currently installed? What thermostat would you recommend most?

Theo

SuperTech

The Honeywell would work just fine as long as it is configured for one cycle per hour.

Unless you are cooking with it, it's not a broiler. I believe boiler is the term you are looking for. 😉

thatguyinunit6

No, I am trying to get it to cook us actually and it's doing a really bad job. . Thanks for the proof read(fixed).

@SuperTech are we doing any damage by using a heat pump thermostat to our boiler? I am wondering what is the urgency of replacing it.

SuperTech

I don't think you are harming anything by using that thermostat, unless the boiler is short cycling. I would still rather have the T5 and make sure it's setup for steam.

thatguyinunit6

@SuperTech thanks for your help.

What would be symptoms of short cycling? I live on the top floor I hear air rush through the blow off valve for about 5min then turn off, and don't actually have hot steam hitting my pipes they are cold.

Does this mean my White Rodgers 1F79-111 is short-cycling the system? Will this do any damage?

How can I diagnose this turn it up 3 deg and see if it cycles?

SuperTech

I don't think the symptoms you described would be caused by a thermostat. It's more likely related to the steam traps on the radiators. It couldn't hurt to have the right thermostat, then move on to other possible problems, such as the radiator vents.

Jamie Hall

My guess is that it is short cycling the system -- which won't really hurt the boiler, but will hurt your pocketbook. It does not appear to have any way to configure it properly for anything except heat pumps and related gadgets.

That Honeywell may work -- provided you have 3 wires and power to the thermostat. Make sure it is properly set for steam, though.

thatguyinunit6

Thanks @Jamie Hall and @SuperTech

Update: I up-ed the temperature 5 deg and the steam kicked on and I now have a nice warm place and the pipes, and the boiler is not cycling(at least as far as I can tell).

Should I take that as a sign that our boiler was short cycling?

Jamie Hall

thatguyinunit6 said:

Thanks @Jamie Hall and @SuperTech

Update: I up-ed the temperature 5 deg and the steam kicked on and I now have a nice warm place and the pipes, and the boiler is not cycling(at least as far as I can tell).

Should I take that as a sign that our boiler was short cycling?

Yes. What is happening is that that thermostat you have is meant for heat pumps -- and they like to run by turning on and off at relatively short (often like 5 minutes on/ 5 minutes off). So that was what it was telling your boiler to do. But steam (and hot water) like to run for much longer at a time, but only once or sometimes twice per hour, and depend on the heat stored in the nice warm radiators to keep things at an even temperature.

By turning the thermostat up, you've fooled it -- temporarily -- into thinking that it has to leave the heat on much longer to get the place warm.

So... get yourself a nice Honeywell (which doesn't have to be fancy!) and set it up for steam -- one cycle per hour -- and stop worrying and be warm. Some of them are programmable in various flavours). Some need power, others work on batteries.

If you need wi-fi connectivity (why?) you will need that third wire, and a fancier thermostat -- but still set it up for steam.

thatguyinunit6

@Jamie Hall the hallway of the unit is usually quite hot as compared to my unit. For example my unit was less than 60 deg yet the hallway temp was set to and maintaining a temp of 78(had set it to 85 to fool it). I think either there is exaust or a uninsulated steam pipe that runs in the wall as the wall is warm when the boiler is running. My hope is that I can keep the thermostat in an accessible place but have the sensors in a location that actually reflects the temp of the units. My unit is likely a good one to have it in as it's furthest from the boiler. We all have adjustable thermostatic valves.

Jamie Hall

Look into the Honeywell Redlink line of controls. Probably will do pretty much everything you want.

SteamingatMohawk

It appears you have a 3 story 6 unit building with a single steam boiler controlled by one thermostat and some number of adjustable thermostatic valves. Being steam heat in Beacon Hill, is this a conversion?

thatguyinunit6

@SteamingatMohawk yes it is in beacon hill but not a conversion it's always been a 6 unit building. sorry I missed this why do you ask?

nicholas bonham-carter

The Honeywell VisionPro thermostat can use averaged remote wired, or wireless sensors, with the control head in a secure location. The sensor must NOT be near a TRV controlled radiator
A hallway is not the best location for temperature sensing, whereas your unit is probably better.
Is this system a one pipe or two pipe system?
It sounds as if the balance of the system could be tweaked a bit, so that steam arrives at each radiator simultaneously.—NBC