Hi All,
I am hoping someone can help me with a nest 3 thermostat. I am a heating and ac contractor and I have the following issue.
I have a two transformer application.
I have a central ac hooked up to
Y1, Rc, C
the thermostat recognizes the three connections and the ac works proper. I only had three wires traveling to the air handler so at the air handler G and Y are wired together.
I have another three conductor cable traveling to the boiler and I’m using RH and W1 connected to the nest. The third conductor is a spare.
The RH is coming straight from the heating transformer to the Nest. The W1 travels back to a Honeywell 24vac zone valve. The other side of the zone valve goes to the common on the heating transformer.
if I measure Rh and W1 disconnected from the thermostat I read 24 vac.
if I connect these wires together my zone valve opens and the operation is proper.
if I wire the Rh and W1 to the nest, the cooling still works proper, there are no wiring errors when looking at the ‘equipment’ setting,
But When I turn on heat, the display is red, asking for heat, but no call for heat in the boiler room. Seems the contacts are hot allowing power to,pass from Rh to W1. I neglected to check in the boiler room if I’m still reading 24 V between Rh and W1 Which would indicate the contacts had not closed on the thermostat. I’ll have to go back to the job site to check that, but am hoping someone has some insight.
any thoughts would be greatly appreciated.
I am unfamiliar with any other troubleshooting measures using the nest setttings. So anybody that could help let me know where to look for any support within the thermostat would be great.
thank you
jon
