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Honeywell T852A thermostat

Can anyone point me in the direction for instructions for one of these? I have a customer that loves his and wants to know more about it.

8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab


  • Robert O'Brien
    Robert O'Brien Member Posts: 3,541
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    Erin Holohan Haskell
  • TAG
    TAG Member Posts: 755
    edited February 2019
    That brings back memories -- we had one on the main zone fo a house as a kid. I believe they ran off a dedicated thermostat.

    There was a wheel under the cover to set the time for set back -- the little dot on the face was am/pm -- I think .. not sowing set back. It had a mechanical lever system that switched the mercury contact from normal to setback.

    It was heat only --