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honeywell smart thermo!!

jerryb
jerryb Member Posts: 113
Bill at honeywell,Sent you an e-mail fri,must have mixed it up.The question is?The stat i have keeps falling back in default to 1pm,made sure R term has power at all time.Thermo powers a honeywell 8043 zone valve,any problem with this? Do you have to isolate the valve thru a switching relay? Thanks in advance..Jerry

Comments

  • BillW@honeywell
    BillW@honeywell Member Posts: 1,099
    T8600...

    That's a power stealing model, that uses a "trickle" of electricity from the heating circuit to operate the thermostat. If the stat is wired so that it powers the zone valve on a call for heat, there shouldn't be any problem, and you don't need a relay. Usually, a system like this powers the zone valve, which drives open, makes the end switch on the zone valve, which causes a relay to pull in on a control panel, or a relay to start the circ pump. If it defaults, or comes up blank, something is completely shutting down the system. Check at the following website http;//hbctechlit.honeywell.com and download a wiring diagram, or consider changing the stat to a T8602 battery powered model. I actually prefer using the battery-powered stats with steam & hydronic systems, since they often operate a bit differently than forced air. I hope this answered your question. Good luck!
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