DIYbanter - Trane Heat Pump Problems

Last spring I had a new Trane Gas Furnce with AC/Heat Pump installed.
It worked great until it was time to turn the heat on in the fall. The
heat pump would come on, however the air wasn't warm. I called the
installer and he came out and thought there was a defective valve in
the outside unit. He replaced that and the air still was not warm. So
after some looking around he said there was a valve in the unit above
the furnace that was incorrectly installed at the factory and he
replaced it. He said that the freon would circulate in one direction
for cooling and the other for heating. He said the valve allowed for
cooling and not for heating. He said it was set-up for an AC unit
outside but it should have been swapped with another type valve when
used with a heat pump. So he replaced that valve and everything seems
to work OK. My question is did running the unit for heat and having the
incorrect vavle not allowing the freon to move in the proper direction
hurt the unit?

Today it is 60 degrees and whenever I turn the heat up only the gas
furnace comes on and not the heat pump. So I have to call the installer
again. Having spent 15 years with a Carrier lemon it seems I'm headed
down the path again of a troublesome heating system.

Thanx for any insight!
jocobe