Air Conditioner Reversing Valve Issue

May 28, 2015
275
Catalina 385 Long Branch, NJ
I have a common problem … my air conditioner cools okay but does not heat. I am now out of warranty. The unit is a Pompanette 16K unit and Pompanette's customer service and technical staff were great in talking me through the issues and how to check them. That said, the leading candidate is a stuck reversing valve. I've already tried the "bang on it" test to no avail. I was advised that the "screwdriver test" on the solenoid may not be conclusive because the solenoid's magnet field is internal to the solenoid (I'm hoping its a bum solenoid). I've posted a picture of the unit after its run for 30-45 minutes on heat (the exact same freeze up happens on cool). The unit is only about 30 months old and replacement of the reversing valve is going to be a huge labor bill. This may sound silly, but are there any old school solutions to unstick a reversing valve? For instance, is there any way to get some form of lubricant injected that would free it up? Too, how hard would it be to test/replace the solenoid?

Open for suggestions … (and I'm resolved to be expert on this system by the end of the season).

IMG_2199.JPG
 
Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
I have a similar but different problem with my Marine Air 16K A/C. When I switch to heat mode I think the solenoid doesn't operate fully and after 3-5 minutes the unit trips the breaker. Different unit and different problem than you but still related to the solenoid valve.
You might be able to get a good answer from Richard at http://www.kollmann-marine.com/.
He has been helpful to me with personal answers for my refrigeration issues over the years. I don't know if he is knowledgeable about A/C units.
 

capta

.
Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
I have a similar but different problem with my Marine Air 16K A/C. When I switch to heat mode I think the solenoid doesn't operate fully and after 3-5 minutes the unit trips the breaker. Different unit and different problem than you but still related to the solenoid valve.
You might be able to get a good answer from Richard at http://www.kollmann-marine.com/.
He has been helpful to me with personal answers for my refrigeration issues over the years. I don't know if he is knowledgeable about A/C units.
Have you checked the water flow on heat? Perhaps as you shift from cool to heat the water pump shuts down. I've not seen this before, and though a remote possibility, it is pretty easy to check.
 
Nov 6, 2006
9,885
Hunter 34 Mandeville Louisiana
You can test the solenoid coil with an ohmmeter. Power off the unit and unplug shore power and turn off any inverter.. Unplug the solenoid coil and check across the two leads.. might be as little as around 70 ohms but could be much higher (around 1Kohm) depending on the control circuit voltage.. also check each lead to the AC chassis to see if the coil has grounded.. an open circuit ..infinite resistance between the two coil leads would indicate an open coil and the solenoid would not work.. replacement coils are typically available..
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Sometimes it's the reversing valve, sometimes there isn't enough "gas" in the system (if you have the ability to recharge it).

We have one of our (now) 19 year old Lunaire units which has a "sticky" valve occasionally -- especially if it's been in cooling mode without have to switch for a while. Turning the unit on- and off- and cycling it from "no heat" to heat has always cleared it.
 
Jun 15, 2012
694
BAVARIA C57 Greenport, NY
I once read in a air conditioner handbook, "80 percent of AC issues are electrical". After making sure that the electro-magnet is working, I would try to free the shaft which is probably stuck. I can't tell from the pictures, if you can remove the electro-magnet from the solenoid (power off, of course). If it can be removed, I would then try to push or pull the shaft and maybe spray some WD-40 on it. I think it's pretty common for the reversing valve to stick from non use.
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
I would try to free the shaft which is probably stuck. I can't tell from the pictures, if you can remove the electro-magnet from the solenoid (power off, of course). If it can be removed,

Isn't the system sealed and no so readily just accessed:


These aren't for marine units, but you get the idea....
 
May 28, 2015
275
Catalina 385 Long Branch, NJ
Everyone's comments are fantastic … thank you … perhaps this photo will provide more clarity on the reversing valve and solenoid:
IMG_2191.JPG
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
The picture tells me the unit is "no virgin". It's been sweated over a few times;^))).

Maybe, it's time again or, maybe it doesn't owe you anything.
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
We should have fun and enjoy ourselves here, not at anyone else's expense.
 
Dec 25, 2000
5,703
Hunter Passage 42 Shelter Bay, WA
the exact same freeze up happens on cool
Different brand here (MarineAir), but soon after taking possession of our 1991 boat in 2002, I turned the forward heat pump on to get heat, but after awhile no heat. I later learned that the seawater pump (relay breaker) needed to be on. When I checked the unit, it looked just like yours; frozen. After that little episode, whenever I turn either system on, I check to make sure seawater is flowing from the discharge through hulls. Not sure what you mean by "the water is rock solid".
 
May 28, 2015
275
Catalina 385 Long Branch, NJ
Ooops, "rock solid" and "water flow" are probably not suited together well. What I meant was that the pump is working fine and the water flow is strong and consistent in both settings (heat and cool).
 
Dec 25, 2000
5,703
Hunter Passage 42 Shelter Bay, WA
AftHeatPump2.JPG
AftHeatPump2.JPG
water flow is strong and consistent in both settings (heat and cool)
Thanks for the clarification. Unfamiliar with the symptoms of a stuck/broken solenoid valve. It would seem that as long as water is flowing through system, whether heating or cooling, that it would not freeze up like that shown in the picture. Unless the solenoid valve is diverting water flow, bypassing what appears to be the condenser (not sure from the picture)?

A picture of ours shows the condenser (white pipes that frost over in the absence of water flow), compressor in the center of the pipes and the evaporator to the upper left that is connected to the fan.
 
Last edited:
Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
Actually Terry, my Marine Air 16K unit will freeze up in cooling mode on a hot and humid day. The freeze up comes from the high humidity and is a normal occurrence. The fix is to shut down until it melts or switch to heat mode for a couple minutes to defrost. Then the system is good to go - until it frosts up again! A no flow or low flow of exchange water will cause the compressor to overheat and then go into shutdown mode.
 
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May 28, 2015
275
Catalina 385 Long Branch, NJ
As I mentioned in the original post, I'm resolved to be an expert in this system by the end of this season. I feel like I'm entering my sophomoric period (otherwise known as "a little knowledge is a dangerous thing"). Having done my share of internet/YouTube research I am anxious to get some pressure gauges on the unit this weekend for a variety of reasons. First, I've seen references (in this thread and outside of this thread) to reversing valves sticking due to a lack of refrigerant. Second, I've seen references to freeze ups due to a lack of refrigerant.

However, my initial temperature readings had return air at 77 degrees and the vents blowing at between 59 degrees to 64 degrees. The manufacturer expects a 15 degree drop and indicated that a 15 degree drop suggests the refrigerant is fine. The manufacturer also said they didn't think refrigerant would affect the sticking reversing valve.

My hunch (and its only a hunch) is that I have a dead solenoid and low refrigerant (maybe this is wishful thinking because this would be the least intrusive and least expensive repair).

I also looked much more closely at my own pictures just now and realized the freeze-up is limited to the center pipe of the three pipes connected to the reversing valve. I'm not sure if this is significant or not but I'm going to do some more homework on how refrigerant flows in one of these systems to see if this is another clue.

Finally, Rich Stidger, I was able to connect with Dick and he gave me a couple of great suggestions (use a compass for the solenoid and a way to test the electricity). Thanks so much for the reference.

Among the dumb questions for everyone … if I want to test resistance across my solenoid … is the solenoid the gray cube with the ridges or is it inside that component? Do you think I need to take things apart to get the resistance tested (there goes that sophomore/little knowledge thing again) …
 
May 28, 2015
275
Catalina 385 Long Branch, NJ
Actually Terry, my Marine Air 16K unit will freeze up in cooling mode on a hot and humid day. The freeze up comes from the high humidity and is a normal occurrence. The fix is to shut down until it melts or switch to heat mode for a couple minutes to defrost. Then the system is good to go - until it frosts up again! A no flow or low flow of exchange water will cause the compressor to overheat and then go into shutdown mode.
And therein lies why I need my heat working in humid NJ in June/July/August …
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
will freeze up in cooling mode
A guess...
You may have a fouled condenser, or you are in the Labrador Current in Rhode Island.;)
_____
Whenever I have a Landlubber shuttle valve, heat pump problem, the Tech gently taps on the valve, then runs it on Cool for 10 minutes, the stops the unit completely, taps it again, Starts it on Heat for a few minutes.
Packs up his tools and charges me $100.:(
Jim...
 
Dec 25, 2000
5,703
Hunter Passage 42 Shelter Bay, WA
Actually Terry, my Marine Air 16K unit will freeze up in cooling mode on a hot and humid day.
Hi Rich, a puzzle. With the relay pump off on ours, the static sea water in the condenser pipes will freeze because of no flow through the system. It seems odd that yours would freeze up in cooling mode with water flowing through the system. Seems normal that frost would accumulate on the outside of the evaporator pipes.