I have a heat pump with electric heat strip auxiliary heat. The heat strips are located downstream of the coil. My thermostat can be configured to allow the heat pump and heat strips to run simultaneously, or to turn off the heat pump when the heat strips are running. My question is, which is the better approach? I ask because when the heat pump and heat strips are on at the same time, I can smell the heat strips (it's not a burning smell, just a "hot metal" smell); this doesn't happen when only the heat strips are running. The heat generated by the heat strips themselves is more than sufficient to meet the heating demand even in the coldest weather. I'm concerned that with the heat pump running, the already-heated air reaching the heat strips might shorten their life (i.e. cause them to burn out from overheating).
Am I just worrying for nothing?