Nest thermostat with dual source heat

[M619]

I’ve currently got a maxim boiler and propane hvac unit. I had 2 thermostats and one would control the fan only at a set temperature threshold. The boiler uses a heat exchanger on the intake side of the hvac ducting to provide heat to the home as long as the hvac fan is running.

the problem I’m having is now that I’ve installed the nest thermostat, it doesn’t seem to be able to control the fan based on temperature, only on time. Have any of you had luck using one of these with a boiler system and back up propane?

[Houptee]

How did you wire the nest and what was the original wiring?

[Jhonleanmel]

Hey folks, 

Thanks for lending a hand, Houptee.
M619, I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,
Mel

[Markjosephp]

Hello M619,

I wanted to see if you still needed help. Please let us know if you have any other questions or concerns.

Regards,

Mark

[Markjosephp]

Hi M619,

I'm checking in to make sure that you've seen our response. If you have any further questions or concerns, please let us know before we lock this thread in 24 hours.

Thanks,

Mark