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Heatpump Making strange oscillations

3K views 21 replies 4 participants last post by  Rollie 
#1 ·
My heat pump this morning was sounding like it was laboring..


Please see this video:
http://www.youtube.com/watch?v=ep7n6uhJopA

Any idea what this means? It was also putting out no heat..

This video was in defrost cycle, but only in backup heat mode of the defrost cycle was it putting out any heat (because the furnace is running..)

It's done this before, if I let it sit it tends to recover and go back to quiet operation..
 
#4 ·
The problem is!

I'm sorry for not watching the video before posting the previous reply. The problem you have is a sticking reversing valve. You can prove this by finding something to tap on the reversing valve while it is in defrost mode. Note: don't try this during normal heating as you would have to disable the outside condenser fan. (evaporator in heating mode). Let me know if this clears up the modulating sound. If it does I will tell what I did to fix mine without replacing the valve. It may work for you.
 
#6 ·
No. I checked my unit and it was charged properly. From the video I'm assuming you have a R410a system. Goodman purchased some faulty Dunan brand valves made in china. They have a service bulletin for the valve in question SR-036 (see the link below). Its possible a subpar lineset installation may have introduced some particles into the system also. If you have this valve, which I believe you do, you only have two choices 1) Have a service technician install a new one. This will certainly fix the problem and you will probably get the part under warranty, but the labor will be hundreds of dollars unless you purchased an extended labor warranty or 2) You can DIY or have a sercive tech inject an 4oz can of "Zerol Ice" in liquid form which is a compatable additive. After injecting the additive you must exercise the valve. To do this you need to force or wait until the unit goes into a defrost cycle and then remove the valve coil control wire from the defrost board and touch it back to the connector. This will remove and provide the 24 volt power to the valve. Please wait until the valve completly shifts. Do this a few times to ensure proper operation of the valve. It may take a few days and you may have to repeat the valve exercise process, but once the additive gets into the system it should lubricate the valve enough to ensure proper operation.
http://www.waroosevelt.com/dealers/service_bulletins/[COLOR=blue !important][COLOR=blue !important]index[/COLOR][/COLOR]

.html
 
#8 · (Edited)
Cool!

I figured out the link.

Is it going to hurt the heatpump to run it in this funky mode? Am I shaving months/years off the life of the unit?

Also, I got a SSZ140301A - Goodman 2.5 Ton 14 SEER Heat Pump Condensing Unit, R410A Refrigerant and it was ordered in June of 2009.

-Jeff
 
#10 ·
It shouldn't, but it has to be in that state to test the reversing valve (by tapping on it). The compressor has internal protections and the system has high and low pressure cutout switches. The Zerol Ice additive should add life to the whole system as well as the compressor.
 
#14 ·
Might be a good idea to have someone check it out. Please keep this in mind. I called a respected HVAC contractor to check my unit out at first. The technician told me he had tested the reversing valve and it was good (wrong!) and I had a bad compressor. I couldn't believe that a one and a half year old compressor was bad. That is when I decided to test it myself.
When I found out the real problem, I called and got a refund ($85). Believe me, you have a sticking reversing valve. As to the additive warranty issue, if you do have an issue at a later date, don't mention it.
 
#19 · (Edited)
Ok,

So I played with it again this morning and was able to re-create the problem.


Here is the heatpump in it's defrost cycle with no problem, notice no droning sounds:

http://www.youtube.com/watch?v=y_4I63LsUik

Everything was just fine. I stopped the video too soon, but what happened was the call for heat went away during the defrost cycle. When that happened the compressor stopped and there was a pop and some hissing. A little steam came off the unit as it was sitting, I then went inside to confirm that the call for heat had gone away..

http://www.youtube.com/watch?v=9Q3-arLlH_4


After about 5 minutes, the thermostat turned back on the heat pump, but the heatpump was still in defrost mode from being stopped half way. It powered up in the funky droning mode at this point. It would not get out of this mode.

http://www.youtube.com/watch?v=Q9sNYOHKQ5w


Then I pulled the breaker on the heat pump. This turned off the compressor, but the furnace was still running and the controller board on the heatpump was still requesting backup heat (white wire). So for about 5 minutes it was stuck in this state. I then turned off the furnace and then pulled the furnace breaker presumably to reset the heatpump controller board..

Now it powered up fine in normal heat mode..



Here is a video of another defrost cycle. No problems. All these videos are in chronological order from this morning.

http://www.youtube.com/watch?v=av-8DuBDLH4

Nothing happens until 3/4 through the video other than my talking about the previous problems..
 
#20 ·
The problem only happens when the defrost cycle is called for. When the unit turns off because the thermostat is satisfied, the 24V is turned off to the reversing valve so the valve shifts over to the heat side. When the thermostat truns the unit back on it tries to go back into defrost mode and the valve tries to shift to cooling. This is when it sticks. When it sticks, you can tap on the valve and it will shift to cooling and the defrost cycle will complete normally. Then it will shift back to heat mode with no problem. This will prove the problem is the valve.
 
#22 ·
I bought a hand pump, turned the unit off, waited about fifteen minutes and pumped it into the liquid side. I turned the unit back on and exercised the valve. The valve only stuck one more time the next day and hasn't stuck since. Its been a week now. Good Luck!
 
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