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Thermostat/Solar Controller


I'll be installing a Drainback-Solar Radiant-Floor Heating System that will work along with my Boiler. The system will use the floor mass as the heat storage medium. I want to set the system up so that even if the zone thermostats are not calling for heat, the zone valves will still open if the solar controller starts the solar loop. However, I still want the thermostats to be able to call for heat and open the valves (and fire the boiler) when the solar loop cannot provide adequate heat. I've got a very vague idea of how to wire this up, but I would appreciate any input or leads. By the way, I've read the entire Tom Lane book as well as the Bob Ramlow book, but I didn't pick up anything specific about this type of control issue.

Many Thanks,

Martin Romero


  • hot_rod
    hot_rod Member Posts: 21,790
    an unusual request?

    somehow you would need lockouts to prevent boiler power from going up to the solar when zones call. And how and where would you monitor solar input to the system?

    Do you have enough panel square footage to contribute to multi zones during winter months?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Dan S
    Dan S Member Posts: 1

    I have been trying to figure out the same thing. It seems that you need a differential control and a zone control box with normally open and normally closed terminals. Somehow it all ties together nicely there.
  • Derheatmeister
    Derheatmeister Member Posts: 1,514
    Why not an tank?

    Is this on a retrofit or on a new system? be careful on a solar direct system! why no storage tank?
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