Reversing Valve

[ApplianceDoctor]

How can you tell if a reversing valve on a heat pump is stuck in mid position allowing gas to bypass from discharge side to suction side causing pressures to equalize?

 

Thank You

 

ApplianceDoctor

[jumptrout]

If you believe the RV is stuck...set the system for COOL and run it.

While running...make and break the orange t-stat wire several times.(at the condenser)

You should hear the RV click.

Doing this several times can often unstick a stuck valve.-+

Watch your pressures as you do this.

If you see achange in pressure you know the valve has activated.

[ApplianceDoctor]

I have found that the reversing valve is energized on the cooling cycle, but also even if thermostat is set to off position valve is still energized. If I cut breaker of to unit you can hear valve coil click as it is de-energizing, or if you put unit in heating cycle you can hear valve click as it is de-energizing. I have tried switching from heat to cool several times and it doesn't seem to make a difference. How can you tell for sure if valve is stuck in mid position or the compressor is inefficient?

[jumptrout]

You are correct.

The valve is energized in the COOL setting.

What I described above will open and close the solenoid to possibly break loose a stuck valve.

Overall,your description is a bad compressor,running and not pumping.

[ApplianceDoctor]

I tapped reversing valve with hammer and valve switched and started working correctly. Thanks for all your help.

 

ApplianceDoctor

[jb8103]

 I have tried switching from heat to cool several times and it doesn't seem to make a difference.

Just by the way, you were likely up against an anti-short-cycling device. The system, if so equipped, will ignore any change of setting made within two minutes of a previous change of setting.

Edited May 25, 2013 by jb8103

[HVAC TECH]

It sounds like you got it running and that's great but from my experience if it happened once it will happen again. The reversing valve should not get stuck in the middle of the valve during normal operation. This is one of the leading causes of compressor failure on heatpumps. If the compressor was damaged while the system was running with the reversing valve stuck in the middle of the valve make sure that a new reversing valve is installed with the new compressor.