Diagnosing the stuck HVAC reversing valve

I show the symptoms of a stuck reversing valve. This one is stuck partway and is bypassing from high side to low side.
If you are a homeowner looking to repair your own appliance, understand that the voltages can be lethal, the fuels are highly flammable and high pressures are used. Know your limits.

[grayfurnaceman]

The troubleshoot of the RV give a lot of us techs fits, especially when the compressor has failed. As for replacing the RV with the compressor, I blow hot and cold on that one. Many locked rotor failures have no damage to the valve but when you have to tell a customer you have to do most of it all over, you kind of wish you had recommended replacement! Great comments.
GFM

[michaelmace]

I just want to take a moment to thank you for doing what you do. I can't even imagine how many people you have helped. The real world knowledge that you give out for free is priceless. I've been in the field for 25 years but was a little weak with heat pumps. We don't really see many of them in Philly. Well, over the past 10 years they've been getting more popular with all of the condos being built. It's cheaper for them to drop heat pumps in than to run gas lines to each unit & set up the gas meters. I think they might be a little lazy too. It used to mostly be people who ran the gas bill up crazy high. But anyway, thanks man. You've helped me out a lot. This video is awesome. I used to feel overwhelmed when on a heat pump service call & hoped the unit was old enough to justify replacement. I can't say I love changing out a 4 way valve, but it's not as bad when you understand them more. It's actually simple now that I'm confident with them. I cut them out & use some couplings, 90s, & Stay Brite though. I've been using Stay Brite a lot since TX valves have become almost standard. I'm lazy & don't feel like doing a nitrogen purge. Thanks Bud 👍😉

[ParabellumX]

Modern college textbooks teach you to that, whenever a four-way reversing valve is suspected of leaking internally, place your temperature clamps across the low-side line (the indoor coil in the summer or the outdoor coil in the winter) and the permanent suction line between the reversing valve and the compressor.
There shouldn't be more than a 3°F difference between them.
Also, be sure to take the temperature readings at least 5" away from the valve body, in order to keep the valve body's temperature from affecting your readings. To prevent ambient temperature from affecting your temperature readings, insulate your leads for better accuracy.
We love Grayfurnaceman! 🥰🥰🥰
Whoosh! Whoosh! 😆

[classic-hbvs]

thanks. I had the same thing and everyone told me it was not the reversing valve and you told me I was right by watching your video. I love it when I can say I told you so lol

[tedj]

Enjoyed your vid sir, I'll forward to young contractor friends in the field. Very simple explanation. Beginning my 50th yr in TX. Blessings!

[TandNServices]

Worse part about a bad compressor on a heatpump once you replace it you may have something like this happening.

[jules]

Thank you! Just went outside & hit mine with a stick! It's blowing cold air now!

[hg.]

Must have solid grasp of the mechanics of reversing valves on this. Luckily GFM has provided a whole playlist on heat pumps. Thanks!

[grayfurnaceman]

I will be doing a vid on the sman. I used them and the testo as a teacher and I actually liked both of them with some reservations. It can be almost impossible to tell the difference between bad valves or a stuck part way valve in some cases. This one was easy because of the position of the slide.
GFM

[vernroach]

Always the best videos...Great refreshers and even greater teaching tools...Easy to understand without all the theory that sometimes, is simply, confusing....Is that an oxy moron?...Anyway, I love this mans videos and learn something every time I watch them....Thanks again to the Grayfurnaceman

[dembonesTV]

Great video! I have found many a bad RV with the temperature differential method! Simple but effective! Thank you for sharing!

[Hunter-cmpt]

You are 💯 right same thing happen to me last week after that I realize that valve is bad…

[jessemendez]

El jefe at it again - great video demonstration boss.

[dembonesTV]

You're right! That's why I always recommend the customer pay for a new RV, too.

[joselopez]

Wow! Thank you so much. Am new to the tech field and this is gonna help me a lot when I do a diagnosed on this type of units.

[grayfurnaceman]

It sounds like the valve actuator is leaking by. Check the power to the solenoid. If it is stable and the valve keeps moving, the valve has failed. I would use a clamp meter to be sure there is no problem with the solenoid. Hope this helps.
GFM

[grayfurnaceman]

Its a 1980s York Champion. The unit is used as a mule to test and do vids, so for now, it has been repiped as an air conditioner
GFM

[kosworkshop]

Will The reversing valve still operate/shift even if you are low on charge?

[grayfurnaceman]

Yes, they are great for accuracy, but still keep the analog ones for the dirty jobs!
GFM

[bbal]

at 2:08 the pressure for the discharge line is 20.4 while for the suction line it shows 257.3