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rfhughes
Nov 23, 2005, 08:08 AM
I recently installed Honeywell #RTH230B thermostat to replace and old Honeywell # T87F( old round non digitital type). I have oil burner with basebaord water heat. Since my olf thermostat was 2 wire only and I have no AC I pulled the jumper wire between Rh and Rc as per the instructions. Thj9is unit has not been working as to changing temps as per the programing. I just read on a borad that since I have Taco Zone valves that draw 0.9 amps I cannot use a digital thermostat. Is this tru can I use any digital= programble thermostat with Taco Zone Valves. Thank you in advance

labman
Nov 23, 2005, 08:51 AM
There are some sharp people giving great answers on the net, and some should be jailed for their advice. Don't let my Ultra expert title or 13 rep power fool you. I don't have a clue if you can use a Honeywell #RTH230B thermostat with a Taco zone valve.

I do know that somewhere in the instructions for the thermostat, it should give the maximum load it can switch. If the zone valve plus the oil pump relay, the circulating pump relay, and anything else add up to more than it can switch, you will have to do something else. Many zone valves use a relay. The thermostat only controls the coil. 0.9 amps is a big load for most thermostat systems. I am not sure even the old one would have handled the load. You may even already have a relay for the zone valve. The ones on the system I know use a double throw relay to restart the actuator to close the valve.