Mine is still active and it is currently 20 degrees. I think I have the heat pump locked out at 10 but I might raise it to 15. If it is above 20 the strips mainly only run on defrost which is very seldom with demand defrost unless it is snowing.

I do have a pellet stove that puts out between 8k and 38,000 btu in the basement. I have the pellet stove mainly for back up heat for an extended outage or when it gets really nasty and in the teens or below to supplement the heat pump. I am considering going to a 20 degree setback and running the stove on high any time it is below 20 and watching how many kwh we use per day.

I am on nat gas. it's a balmy 20 degrees this morning in the South with a winter storm on the way. felt sorry for the outside cat and let her come in with the dogs last night. those with straight HPs and electric backup are making the electric companies smile today...

We went through a cold snap down in the 20s a couple weeks agho and expect some more of the same a little later this week. I run mine down to 20 and have natural gas backup. I admit the unit struggles somewhat to get to the set temp during recovery. Setbacks are three degrees, but am going to adjust to two degrees when it fals into the 20s.

I sometimes use the fireplaces to help achieve set temp. However, once there, the HP maintains temp very nicely. When it goes under 20, it's all natural gas. I'm in Olympia, Washington.

Our 2001 Carrier heat pump gently blows warm air at body temp down to 0 degrees F or colder. The aux elec strip heat rarely comes on, but when it does it seems to be right after defrost mode. We keep it at 70 day and 68 night during the winter and use the fan in "always on" position with heating. Our 2200 sf home is standard frame bi-level, circa 1982, and is well insulated and has new windows. Our highest total electric bill is around $180 in January with elec rates at $.12/kwh. Our lowest bill is in Sept/Oct and runs around $70 with minimal heating/cooling. The system runs quiet and has Aprilaire filtration. Other than our elec rates being the highest in IN, we are very happy with our reliable and economical heat pump.

My cooperative isn't going to be smiling in the next day or so when it heads possibly below zero Tiger. They put a rebate program in place for dual fuel units only to attempt to get people away from strips. Heat pump 15 seer or higher with demand defrost and gas back up is now worth a 750.00 rebate. When the peaks hit in the winter and the strips all start coming on it costs the utility way more than they make.

I will be burning pellets in the basement to supplement so I don't have to pay them so much for these cold spells.

I am going to supplement with a pellet stove in the basement