Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Automatic Thermostats and Steam Boilers?

HowardHoward Member Posts: 57
The honeywell adjustment screws will select one of maybe three cycle rates. If you've set it for steam, you've selected longer cycles, or more accurately, less cycles per hour. Unfortunately, thermostat designers have determined that more complaints are made against large temperature swings than about short cycles. As a result, programmable thermostats might not let your system run long enough at each cycle.

YMMV(Your mileage may vary.) The size and configuration of your piping and size and condition of air vents and probably a few other factors determine how quickly your system heats. If your radiators heat up pretty fast, I'll bet the programmable will work just fine.


  • Fred LobmeyerFred Lobmeyer Member Posts: 5
    Automatic Thermostats and Steam Boilers?


    I am a home owner and was wondering if Automatic Thermostats and Steam Boilers mix well. I have been reading many of Dan's articles and reviewing all the problems that I am having. I am wondering if the Automatic Thermostat is also adding to the problem. It is a Honeywell 3 day (weekday + Sat + Sun). It has adjustment screws on the back which I have set for Steam.

    My concern is that this thing is supposed to adjust for lead times to bring the house up to temperature at the desired times. It also has a feature called "Adaptive Intelligent Recovery" that will "...turn the equipment on and off several times before reaching your comfort time to save energy by avoiding overshooting the comfort temperature." The model of Honeywell that I have is the "CT3400" series.

    Based on some other pictures on "The Wall" and coments from Peter Desens I appear to have a Utica PEG-A series Steam Boiler.

    Does anyone have suggestions on Automatic Thermostats? Do they mix with Steam Boilers? Can you correctly operate a One Pipe Steam system in this fashion? If Utica is still listening do they have recommendations or tested and authorized automatic thermostat models?

    Thanks in advance!
  • SteamheadSteamhead Member Posts: 13,765
    In order for a Programmable Thermostat

    to work well on steam, the system must respond quickly to a call for heat. This is possible when the steam pipes are insulated, mains and radiators properly pitched and vented, and the boiler clean and in proper tune. These items in themselves will also lower the fuel consumption.

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • YvonneYvonne Member Posts: 2
    Any t-stats on steam boilers

    I find it best to install a t-stat relay in the boiler room on any boiler system when using a programable or a standard t-stat. Otherwise you will get cycleing in a month or so, and your system will never heat up.

  • HowardHoward Member Posts: 57

    Are you referring to a relay that self-energizes on any momentary call for heat then drops out on pressure or a fault?

    Howard Hansen Service Technician Extraordinaire
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!