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t'stat for slant fin kicker

iziz Member Posts: 10
Can I use a "nice" line voltage thermostat for controlling my fan on a kickspace heater in lieu of the factory aquastat? The aquastat on my new slant fin kickspace heater has gone bad. I would prefer to control the fan based on space temperature in lieu of water supply temperature. I have a viessmann boiler which constantly circulates water so the fan controlled by a t'stat shouldn't create any times when there is no hot water but a call for heating by the kickspace heater t'stat.

If so, can someone suggest a digital display line voltage t'stat and some insight on my application.



  • ZmanZman Member Posts: 6,035
    Always on?

    Do you have a residential heating system that is always on? That seems really inefficient.

    Usually a kickspace heater would be wired with an aquastat and a thermostat wired in series. That way you would never blow cold air on your feet. I wonder  if you have a high temp aquastat in your heater. Mod/con boilers often run lower temps and may not be tripping the stat.

    I have used these  and had good luck. Be sure to use a 120 volt model

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • iziz Member Posts: 10
    edited November 2012

    Yes, my residential heating system is always circulating water when in heating mode. The burner isn't always on but the pumps are. Its a Viessmann mod/con boiler and that is how the system operates. So far it's actually very nice.

    Just like you said, the Kicker comes with a 130F aquastat which I don't want to use. The system puts out low temperature water and there have been days when the house is plenty hot and the boiler is only making 110-120 water but the room with the kickspace heater is cold because it hasn't kicked on because the aquastat hasn't closed yet. I just want to bypass the aquastat and control fan directly with thermostat. I'm not worried about blowing cold air because the water is always circulating. I guess if I can get a low temperature aquastat then having it in series with the thermostat would accomplish the same thing. can I use a low temperature aquastat manufactured by beacon morris?

    Do I need a particular type of t'stat? I see some have minimum loads requried around 2A. My kickspace heater has a max load of like .27A.
  • ZmanZman Member Posts: 6,035

    Any aquastat designed for 120 volt will work. As long as you can get good contact with a pipe. I have seen inexpensive "snap disk"stats  installed on appliances like that. You may want something adjustable like a honeywell or white rodgers strap on. At some water temp the air will feel cold coming from the heater. An adjustable stat will help you dial it in. I am unaware of an load minimum on a 120 volt t-stat..

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
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