In alt.home.repair, you wrote:
It sounds like either a sticking reversing valve or a weak coil. It might
also be incorrect refrigerant charge.

"lp13-30" wrote in message
...
If the reversing valve is getting power during heat cycle, other than
during the defrost cycle, it is getting that power from one of three
paces: the thermostat, a short in the wiring between the tstat and air
handler or the air handler and condensing unit, or a faulty defrost
board. Anything is possible of course, but I do not recall ever seeing
this particular problem with a thermostat or defrost control. Disconnect
the orange wire from the thermostat and if the problem continues, it is
not the thermostat. Then disconnect the O wire at the condensing unit.
If the problem continues, it would indicate the defrost board. If not,
the wiring. Good luck Larry



Thanks!. This is exactly the information that I was looking for.

* I disconnected the orange wire from the thermostat and turned
on the heat pump.
* It put out good heat and the voltage at the disconnected orange
wire was 26V.
* About ten minutes later, I heard the swooshing sound of the
reversing valve and the unit began to blow cold.
The voltage at the disconnected orange wire at the thermostat
read 0V.
* The heat pump continued to blow very cold continiously
(longer than 30 minutes) and I climbed on the roof and
checked the unit. The external fan *is* running.
* I'll see if I can figure out where the oragne wire at the
condensing unit is.

Thanks,
-Ben