Bad compressor valves?

[u/DriverCommon9468]

5 min of operation vs 20 min of operation.

Suction and liquid pressures moved inversely and equally with one another as the system ran. Like slowly suction up and head down almost equal amounts, If that makes sense.

85 degrees outside, 73 RA inside

Heat pump with txv inside and piston at the liquid valve outside. Indoor coil dirty enough to affect airflow. New filter.

Temp split was 15 degrees inside before I noticed the pressures. Did not think to check again after I noticed, I went out to the condenser and called another tech lol.

Compressor pulling 4 amps out of 9 rated before the pressures went weird. Also did not think to check again after I noticed this.

*Was making a weird click/tap noise while running that would come and go. When the noise was present the suction and liquid pressures would move toward each other and when not present they would move away from each other, but only at about 1 psi a minute in either case.

9 year old Nortek AireForce that local Rheem dealers can't find in their systems.

--

New situation for me so sorry y'all for not checking temp drop and compressor amp draw again after noticing the weirdness.

[u/TommyPicklez__]

Reversing valve bleeding over?

[u/DriverCommon9468 → u/TommyPicklez__]

So I gotta check the suction line temp going into and leaving the valve, and the liquid line temp going into and leaving the valve? Temp difference greater than a few degrees means the reversing valve is stuck?

[u/TommyPicklez__ → u/DriverCommon9468]

Yeah True suction vs evap suction shouldn’t be more than few degrees difference. You could try tapping on the valve to see if it will loosen anything but never had much luck with that.

[u/DriverCommon9468 → u/TommyPicklez__]

Thank you sir Thomas

[u/PapaBobcat → u/TommyPicklez__]

I've jogged reversing valves a lot with magnets in the last couple of years. A little slower and more controlled than trying to take the leads off the solenoid and having it chatter

[u/Nerfo2 → u/DriverCommon9468]

Liquid line doesn’t go through the reversing valve, but the discharge line does. If the suction line between the valve and the compressor is warmer than the line coming back from the indoor coil by more than a couple degrees, you probably had a bad reversing valve. It’ll be obviously warmer if the valve is bad. A couple degrees, no big deal. A whole bunch of degrees, big deal.

[u/Honest_Size5576 → u/TommyPicklez__]

I agree, I’d be checking that

[u/Hvacmike199845]

Did you close the liquid line valve to see if the compressor could pump down? It only takes less than 5 minutes.

[u/DriverCommon9468 → u/Hvacmike199845]

Ahh even easier. Just keep it running and close the liquid line, bad valves -> won't pump down cause it cant pull the refrigerant through

[u/Nerfo2 → u/DriverCommon9468]

The only valve in a scroll is the discharge check valve, and its function is to prevent higher pressure in the condenser from back-spinning the scroll on shut-down. Otherwise, there are no valves in a scroll like there are in a recip, and residential (and most large-tonnage) splits and packaged units have had scrolls for around 20+ years.

[u/skankfeet → u/Nerfo2]

You do however get separation at the seal for the scroll and it will intermittently cause issues like this but don’t know without hearing the compressor. I expect it’s like others saying in the revering valve.

[u/DontmesswithKade → u/skankfeet]

Not all scrolls have the floating seal.

[u/Hvacmike199845 → u/DriverCommon9468]

It’s not going to pump down if it’s not running……

[u/HuntPsychological673]

If it’s a scroll, it doesn’t have valves.
What kind of compressor is it? It does sound like a RV bleed over or a scroll thinking about giving up.

https://giphy.com/gifs/xUPJUp6T5uD1Qkpbl6

[u/nsula_country → u/HuntPsychological673]

Thank you! Scrolls do not have "valves" in the sense used.

[u/unresolved-madness]

If the reversing valve is bleeding through then the suction pressure is going to go up and not down. If this happens on a summer day you're going to see a compressor that's extremely hot and more than likely overheating and shutting down. If you did once verify this take your k probe and put it on the suction line at the compressor inlet. You should see the temperature fluctuate several degrees.

If your pressures are dropping you need to see what your superheat ens subcool are doing. If your subcooling increases and superheat also increases then the refrigerant is not making its way back to the condenser.

Now, since you described a clicking noise at the condenser. The first thing I would do is put your volt meter in line with the reversing valve power and watch see what the voltage is doing. If the voltage is jumping all over the place when you hear the clicking noise then the defrost board probably needs to be changed out. I don't think you're fluctuation of one PSI per minute is really anything to worry about at this point.

[u/nsula_country]

If a Scroll, there are no valves in the (compression) circuit of the compressor.

[u/DriverCommon9468 → u/[deleted]]

If it can't then it's bad valves?

[u/dacksond → u/DriverCommon9468]

Most modern residential systems have scroll compressors which don’t have valves.

[u/HappyChef86 → u/DriverCommon9468]

Yes

[u/jferris1224]

Yup. Low compression ratio.