Heat Pumps and Electric Heating - Heat pump and high pressure control problems

I am a homeowner, not a pro, and need some advice.

I bought a 3 yr old home this spring and soon found out our heat pump outdoor unit fan was not working. Service tech found the high pressure control had been wired around and replaced it and recharged the refrigerant. Seemed fine all summer and elec bills reasonably low.

I have noticed lately that the heat pump seems to be constantly running to keep the house at 68 (temps have been in the teens and 20s). Two days ago, the fan outside stopped running again. I hit the reset button and it tripped again. That morning it was only 6 degrees and the power went out about every 8 minutes for several hours. (Fun morning!!!)

The service tech now says that it may be a restriction in the refrigerant line and will install a line filter and replace the refrigerant to the tune of $800. He said that may not solve the problem - there is a chance it is the TXV valve, which is hard to troubleshoot, he says. He recommended replacing the outside unit instead of going through all of the repairs which may or may not fix the problem.

I'm getting a second opinion - another tech is coming out next week and thinks it could be the refrigerant is overcharged.

Has anyone had heard of this before? I could really use some advice so I don't get taken for a ride! I have never had a heat pump until now so I don't know anything about them.

Switch the system to emergency heat and get the second opinion. It could be overcharged, it could be restricted. There could be other problems as well, but it's hard to say without being there. Try to find a tech with lots of heat pump experience (easier said than done).

Heat pumps tend to run all the time especially when temperatures are in the twenties.

Rheem? its a common problem usaly trips when comming out of defrost, recovering some of the charge will fix the problem untill summer when they will add some refrigerant, check air filters change if dirty, duct work? hard to tell without seeing it.

The only reason to replace the refigerant is if its contaminated. As it does seem to be overcharged or there is a restriction at the air handler, it is doubtful that is has been contaminated. The system is sealed and unless it leaks out nothing can leak in. Beware.