Hi, I live in Montreal, Quebec, Canada, and here people who has an heat pump and oil backup can get a better eletricity price, above -12 celsius. Below that point, electricity cost a LOT more.
I have 2 wires coming from that system, normally closed (above -12 celsius), and open (below -12 celsius). I use them to control my "Y" heat pump wire. It works great. My heat pump will never work below -12.
The problem is that, below -12, my thermostat (Carrier TSTATCCSAC01) will energize the "Y" wire for heat (has no effect, open circuit) , wait 15 minutes, then energize the "W" (oil backup). During these 15 minutes, it's getting cold in the house ! I must manually set the the thermostat to "Emergency heat" to counter this behavior.
How can I tell the thermostat to go directly in oil backup when below -12 ?