On May 8, 12:57 pm, Freud wrote:
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,
Freud

Wouldn't it be simpler to just have a qualified serviceman disconnect
the heat pump's electric heat. Then just set your heat pump to
whatever temp you like and your furnace to 3 or 4 degrees cooler so it
will kick on when the heat pump can't handle it.

As for your question. Could you wire the heat pump's control to turn
on the furnace instead of the electric heat? No. Could a qualified
electrician do it? Yes. Would he? Probably not. Would it be
legal? Maybe.

The problem is that would probably need a control box with a relay to
interconnect the systems. That's a bit unusual and you would need to
talk the electrician into doing something like that because it's a bit
strange. Disconnecting the electric heat, OTOH, is just a few wire
nuts or screws.