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Replacement Thermostat for \"TS 86A\"

I need to find a replacement thermostat for a "TS 86A", which is spec'd on the boiler. This is for a gas fired steam boiler (1 pipe steam).

I suspect this is a "millivolt" thermostat. The currently replacement is a Honeywell that is not a "millivolt" and I'm having heating problems (i.e. the heat is not consistently being regulated).

Any help appreciated.

/harry

Comments

  • The TS86 is a mercury

    bulb thermostat and has probably been discontinued by Honeywell, I know as of last Oct 1 they stopped production on the T87F mercury bulb 24 volt thermostat.

    There are still "millivolt" (750 Millivolt) thermostats available. they are TS822A-1039, TS810B-1007 Heating & cooling, TS812 heating only.
  • Harry Collins
    Harry Collins Member Posts: 2
    found a replacement

    I ended up going with a "Home Depot" digital thermostat that claimed millivolt support. Things seem to be working fine.

    There was a T87F on it, and that wasn't working. I replaced it with a newer T87F, and that didn't work. I finally figured out it was the "millivolt" issue and now I've replaced it properly.

    /harry
This discussion has been closed.