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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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To you. I have a Trane XE1000 heat pump system. The reversing

Customer Question

Hello To you. I have a Trane XE1000 heat pump system. The reversing valve is working
ok and it whistles when it switches. The gages read 65 on the low side, but only about
80 on the high side when running. That is on the gage scales for R-22. Why is the high pressure side so low. My unit was installed in 1998 so it is quite old. Is it possible that the compressor is so worn out that it can't hold the high pressure?
Thank you for your help. Doug
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Welcome! Your question will be answered in detail. UP to 48 hours step by step coaching on diagnosis & repairs $38 additional.
The valves in the compressor are bad as you suspect (90% chance of that)...or you are operating your test gauges so that hot gas flows from the the high pressure connection to to the suction pressure connection... and.. at the same time the system is about 50% low on refrigerant. (10% chance of that.
To this close the hand wheel on the red gauge connected to the high pressure side, if the suction pressure (low side) changes you were testing with the service manifold set to bypass hot gas to the low side.
Let me know about that in particular without any other assumptions.
The reversing valve could be bypassing high pressure gas to the low pressure side due to leaking internal seals or the valve not switching positions completely.
Diagnosing that is a bit more difficult.
With the compressor running for 10 minutes or so, put your hand on the largest copper tube connected to the compressor, then shut the unit down, If you hear a gushing sound and the suction line warms up quickly then either the discharge valves inside the compressor is bad, or the reversing valve is bad.
If the suction line connected to the outside unit gets suddenly warm but the suction line AT the compressor does not get warm then the 4 way valve is bad.
These are complex instructions, read them over a few times, then conduct these tests a few times until all starts making sense to you... we can go from there.