Seen a good number of RVs stuck in the middle, and no real pressure change while the compressor is running. Sometimes might get a 5 PSIG change on the high side. Which is what the OP is describing.
Anyone remember when Goodman was using those grossly over sized RVs, and they wouldn't switch all the way over.
If the screen of an accumulator on a heat pump is plugging up. Then the RV has gunk in it also. Which will prevent it from moving.
There has been a time or 2, that I condemn as compressor as not pumping with the OP's same symptoms. And after installing a new compressor, same thing. Change out the RV, and everything worked.
Perhaps this will assist me , inlet to the accumulator is "open" both to the "J"tube and the cylinder at the top of the accumulator than only open to the "outlet" of the accumulator via the outlet or the port/screen at the bottom of the "J" tube and finally out to the compressor?
Thanks for the unit info. If I am understanding what you are saying in this post then look at my post 122 and tell me how that does not apply. If it applies then that rules out the accumulator except for maybe gunk from being oil slugged which brings us done to either a compressor or RV and the compressor has been changed. I was going to ask if there was a filterdrier between the accumulator and compressor that could get plugged but then you would have a port.
On the only accumulator I have cut open, the outlet tube looped to the bottom of the shell and then extended almost to the top of the accumulator shell and was an open tube at the top of the shell to allow the shell to fill up with liquid and the outlet tube still be in the gas area of the shell unless the accumulator was full. The end of the tube was open with no screen on it.
At the bottom of the loop was a screen covering a small hole that allowed liquid refrigerant or oil that accumulated to slowly bleed back to the compressor. The purpose of this screen was to keep the small hole from plugging up.
If the screen was plugged it would stop the return of liquid and oil to the compressor, but the suction gas would still be open to flow from the open tube at the top of the shell.
It is a "Payne" PH15NBO3600GBAAA, APROX 5 YRS OLD.
Thank you !
Unfortunately being a Payne I found limited information on the piping and refrigerant circuit.
So I ran some numbers thru Carrier and was able to come up with this image.
Possibly rundawg has more information on your heat pump.
Does this match your set-up ?
The inlet screen I'm referring was at the inlet of the accumulator, not the oil return port. I doubt this newer accumulator has the inlet screen. It's probably a stuck RV.
What happens if you open your gauges connecting dedicated suction and vapor line ? Between dedicated suction and liquid line ? Just speculating here but if a blockage after rv wouldn’t you start drawing in refrigerant ? When you charged the system did you only put in on the liquid port? How long before pressure came up on low side ?
To answer the original question: YES a stuck reversing valve can cause your symptoms.
New questions: What caused the RV to stick? Could this compressor be from the 2014 era, where the oil additive caused a lot of TXVs to gum up?
To answer the original question: YES a stuck reversing valve can cause your symptoms.
New questions: What caused the RV to stick? Could this compressor be from the 2014 era, where the oil additive caused a lot of TXVs to gum up?
Often times the pilot tubes wifey oil logged, sounds familiar, like the accumulator maybe. When this happens the valve usually won’t shift but if it starts it could stop anywhere in between.
I agree, will a strong nitro purge be able to clear oil logged tubes?
Originally Posted by BNME8EZ
Often times the pilot tubes wifey oil logged, sounds familiar, like the accumulator maybe. When this happens the valve usually won’t shift but if it starts it could stop anywhere in between.
I agree, will a strong nitro purge be able to clear oil logged tubes?
Not that I know of but I have used a propane torch to heat them up while working the valve which thins the oil and gets it to move out. Then push the tubes back as tight against the body as you can and tape them there with Al tape, then cover with armaflex to keep them warm. That works if the valve is stuck in heat or cool but in the middle you don't have the pressure difference to get it to move.
First , trying to post a new question/statement has been most difficult on this site. maybe someone can give me a quick way to do this, Second, I have resolved my problem re heat pump , compressor runs but no pressure change. If I can find an easy way to make comments on this site , I would be happy to post my results and get some feed back as well. HELP on posting please.
First , trying to post a new question/statement has been most difficult on this site. maybe someone can give me a quick way to do this, Second, I have resolved my problem re heat pump , compressor runs but no pressure change. If I can find an easy way to make comments on this site , I would be happy to post my results and get some feed back as well. HELP on posting please.
Just reply on this thread like you just did that's how we do it here we don't need a new thread just comment your findings
Heat pump 3 Ton scroll, 240 v single phase , compressor runs (6 amps) correct direction, seeing "almost" no change at ; Ll, suc. , and/or "true suction" access ports on my gauges . I have the answer now but still would like feed back as to the "least expensive way" to diagnose the issue. I considered these two possibilities , 1 , accumulator filled with oil and not allowing any return to compressor , 2- failed reversing valve, but I could just not rationalize how the Reversing valve could fail in such away as to create these symptoms, thinking that it would have to be stuck (mid way perhaps) allowing almost a complete bypass. That was not the case, it seems, after dissection of the rev. valve that the plastic/neoprene glide on the bottom of the "shifter" inside the rev. valve warped , allowing a bypass through discharge to all three ports exiting the rev. valve. Anyone else ever seen this ? Again, what is the easiest/cheapest way to diagnose ?
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God Speed, Jim. We'll miss you - 2-26-23
Originally Posted by townsend
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