"Freud" wrote in message
...
Hi:
We have a 1930s Cape Cod in MD. It has a natural gas boiler for
radiators, and a heat pump/central AC system. The two systems are
controlled by two separate thermostats. My question is, can I get a
single thermostat which will allow me to control the two systems so I
can be as energy-efficient as possible? Around here it gets cold enough
so that the heat pump will doubtless fall back to its aux heat, which is
quite inefficient. What I'd like is to use the heat pump when it's not
too cold out, then switch over to the radiators as the aux heat. Can I
maybe wire the heat pump thermostat so that it kicks on the gas rather
than the resistance heat? Any ideas would be appreciated.
Thanks,

I'm sure it could be done. You would probably want it set up so the
heat pump would still use the resistance heat during the defrost cycle
to avoid cold drafts. Basically, you'd want the auxillary heat signal
from the thermostat to go to the boiler rather then the heat pump,
perhaps with a relay to isolate the systems. If you are handy with
electricity, you might handle it fine yourself. You could call any local
heating/AC contractor and ask them what they'd charge to do it.

Bob