Our heat pump will run and heat fine for days, then without warning will seem to stop heating. The room temp may be 70 degrees, and the thermostatt set at 70 degrees, but it will run non stop, actually cooling down the house. We finally shut it down when it gets down to 66 degrees in the house. It is like the system has reversed and it is cooling. The air is noticeably cooler coming out. Unless we turn up the thermostatt to kick-in the heat strips, the unit does not heat the house. The outside temp is 45 - 55 degrees, so it is not like it is that cold outside. Is the unit freezing up or is it something like a valve reversing? Help!

I have a bad Low pressure switch on a Jantirol Heat pump.Does anyone know the replacement procedure?Does it solder in or screw in. Do you lose freon and have to recharge?