Heat pump reversing valve

[dshogman]

I was told there is such a gizmo in the heat pumps and that if you don't get what you want (like cool) when in "Cool", to try it in "Heat Pump" for a while and then go to "Cool" again. So after cooling fine all the way from Vermont down to Texas (4 weeks on the road), the other day in Pensacola, I actually had to use the heat in the morning. Today, hot air from the "Cool" function. I did the routine mentioned above, the "Cool" then came on fine for about a minute when it started warming up. Any thoughts from the experts out there? I'll be "home" in Kerrville tomorrow where there is a very good RV tech so I can have it looked at there. Just wondering if anyone has had similar problem.
Thanks.

[RVhauler]

Sounds like a stuck reversing valve. Using a strong magnet held along side of the reversing valve slowly move the magnet along the valve body. This will sometimes free a stuck valve. Replacement is rather expensive

[OldForester]

David,

Our front heat pump has periodically stuck for the 4 1/2 years since we owned it. Usually worse when moving from summer to winter or vice versa. It has almost always reset itself after running in the opposite setting - cool when we want heat -- or heat when we want cool - for a few minutes then back to the setting we want. However, one time it did not switch to heat and stay switched when we went south for the winter. Our mobile tech in Palm Springs looked at it and moved the temp sensor that alerts the A/C from freezing up, farther away from the body of the heat pump. He said it was too close and it the probe needed to have more air space. I didn't see him move it but thought I would pass that on as another idea. Has worked fine since.

He also said the alternative was to replace the entire unit; not a cheap thing to do if you don't need to.

[Old Rv'er]

Hmmm, I had one stick as well, just went the other way, and let it run for 15 minutes or so, and then switched back, it worked fine after. It seemed to help that I used power from the genset instead of the shore power at 15A.

Since WRV is gone, and some of our rigs are starting to age, it's not an easy thing to just switch the A/C units and expect them to work like they used to. One Reason is the wiring that was used when they were new versus what is being done now days. So if you have to change out a unit, before you take the plunge, make sure whoever does it has a plan to make sure the new wiring will work with the old thermostats, etc. Also, the playing field is a lot smaller now with Carrier out of the RV market, and maybe a new AZ player in, so it's going to get interesting with the newer coaches out there.

[takepride]

When my front AC was changed, it required changing the control board for the rear AC, too.

[dshogman]

Follow up - have been trying all the suggestions. A little while ago, I started the "cool" cycle - seemed to work fine. Cold air, temp down to 56. I thought all was good - then after about 5-6 minutes it started warming up significantly. I shut it off when it hit 78. Any more thoughts based on this info?
I'll have the local tech replace the valve in a few days.

[dshogman]

Working fine now. Tech went up there, did a lot of testing and finally replaced a solenoid (he said) that was not functioning.

[JVR]

I've tried switching several times to no avail, whether on heat pump or cool the output temperature remains the same, not cool or hot. I guess I'm in for a unit replacement? The compressor run in both modes.
JVR

[Wayne R]

JVR, if you can, go up and verify the reversing solenoid is energized. I believe the solenoid is active in cooling mode. I had a capacitor go out and when I replaced it I knocked the wire off that energizes the reversing valve. Mine blew hot air in both modes I hooked up the wire and it started cooling again. I only ask you to check this because on mine the coil can be replaced on the valve . You may have to buy a new valve to get the coil but that would be a lot less expensive than replacing the whole unit. If energized it should display a strong magnetic force on the shaft securing the coil.