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Steam heat compatible thermostats

ceksenior Member Posts: 44
Hello heating pros, once again I need a little assistance which i hope you can help. I have a gas fired steam boiler with a hot water loop for zone heating. The ground floor and basement have the hot water loop with Honeywell Pro 4000 programmable thermostats. The upstairs bedrooms run on the steam heat and have a Honeywell Ct3400A thermostat. The upstairs steam heat cycles quickly and the radiators barely have a chance to get hot before the thermostat shuts the boiler off. Ive been looking into getting a new thermostat and read on one site that this thermostat is not compatible with steam heat. Is there a special thermostat I need for steam heat, and if so which is the best. Thank you.


  • V8toilet
    V8toilet Member Posts: 71

    The Honeywell RTH7400 thermostat is a good programmable thermostat with a learning function that learns the overshoot of your steam system and compensates for it. I have had this thermostat running my system for about two seasons now and it works very well. This thermostat has kept the temperature within one to two degrees from what I set it at. I tried many other models before this one and they had trouble controlling the overshoot of my steam system and the temperature would swing five to ten degrees.

    When you set it up it has a setting for steam systems so it is steam system compatible. I got it for about $80 at Home Depot. After you configure it and set it up it will take a few cycles for the thermostat to learn how your system runs but once it does the temperature control is amazing.
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