Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
If our community has helped you, please consider making a contribution to support this website. Thanks!

New thermostat, not sure if it's short cycling

Options
Patrick McGrath
Patrick McGrath Member Posts: 60
in Strictly Steam

Hi all:

It's been a bit since I've been on here. I just had my boiler cleaned by a new company earlier in the year. Everything was fine, but my round Honeywell thermostat ended up having issues, which I attributed to an issue related to cleaning the boiler. Guy came back, said the tstat was bad, said he had another available. I asked if it would work correctly with a steam boiler, and he said yes. So, we've had it a couple of months. Our house has been quite evenly heated as a result, but I am starting to suspect that this one is short-cycling the boiler. Hard to tell with my bills at this time, as gas and electric has spiked so much.

Pic attached. If this isn't adequate, I'll figure out how to get it off the wall and see if there's a model number inside. Thanks for any help.

IMG_8566.jpeg

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 27,395

    May well be running shorter cycles than are ideal for steam. Thoose usually ship set up for hot air…

    Do you have the manual for the thermostat? If so, it will guide you through using the settings under the menu to set it for steam heat. Not hard to do.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • geemalar
    geemalar Member Posts: 100

    FWIW………I had a short cycling issue due to an incorrect spec thermostat left over from a previous oil fed boiler. Based on a recommendation by Ed The Heater Man, I fitted one of these to my single pipe steam natural gas boiler. Nothing fancy, set and forget style. Complete game changer. My system now runs on longer cycles, I currently have it set to one CPH. Hasn't been really cold enough to change the number of CPH, as some have mentioned I may want to increase it based off of the comfort in my house. For now, I leave it as is, as it works better than I ever anticipated.

    https://www.supplyhouse.com/Honeywell-Home-TH1100DV1000-PRO-1000-Non-Programmable-Heat-Only-Vertical-Thermostat

  • HVACNUT
    HVACNUT Member Posts: 7,467
    https://forum.heatinghelp.com/discussion/204134/new-thermostat-not-sure-if-it-039-s-short-cycling

    The tech should've set it up for steam in the Installer Setup. If you get the actual model, you can download the installation manual or come back here. It's easy. It'll look like this.

    Screenshot_20260324_201326_Samsung Notes.jpg

    ISU 200 = 3

    ISU 205 = 12

    I see the thermostat is in permanent hold. You can also set it up to be non programmable as well if you want.

  • 4GenPlumber
    4GenPlumber Member Posts: 175

    Keep going through that menu until you get to CPU as previously mentioned. Depending on your system it should probably be 3, 2, or 1. Start with 1 for longer fire time but if the house temp drops too much, go to 2. 3 only if you have poor insulation, bad windows, or perhaps under radiated, but thats means you are losing a lot of heat no matter what.

Categories