I am installing an Omnistat 2 thermostat in an older conventional single stage HVAC system with no ground from the thermostat to the furnace circuit board. The system worked fine with a regular programmable thermostat. I am pretty sure that the wiring is OK. The Omnistat will engage the system, i.e., it will operate the fan and tries to operate the system. The burner fan will come on but it will not ignite. The cooling condenser will try to start but will not come fully on. It looks like we do not have enough power (measured at 24VAC) from the furnace circuit board to both operate the Omnistat and trip the relays to start the system. I have a separate 24VAC power supply available and attached that to the Omnistat, but did was not sure how to attach the second side of the power circuit to the furnace board. The power supply is not the one recommended by HAI but does produce 24VAC. Will purchase the HAI supply if it will solve the problem. Would appreciate any help with solving this problem. Thanks.
Omnistat Install in older furnace
- Thread starter alpalmer
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