Community Forums

curtismb · 06-11-2019, 02:38 PM

Unit is one of two on Comfort Control 2-Zone Thermostat. Both are 13500 btu ac/heat pump Dometic mdl 630515.331. One unit works great in all settings while this one last Friday put out heat when turned on to Cool. I have run it alone and it responds to all settings as it should except for Cool where it is putting out true Heat.
I doubt if it can be Thermostat because thermostat responds to all functions for both units except for the fact that this unit only puts out Heat in Cool setting.

Anyone experience similar situation?

Outbound · 06-11-2019, 04:18 PM

If I remember correctly I think there is a reversing solenoid that reverses refrigerant flow when going into heat mode, might set stat on cool and tap on solenoid to see if it is sticking.

Ivylog · 06-11-2019, 05:51 PM

The default on older units is heat and you can buy just the reversing valve coil which is usually what causes this...could be the board but less likely.

jacwjames · 06-11-2019, 06:12 PM

Same thing happened to me, one day it quit cooling and just blew hot air.

I suspected the reversing valve so went on the roof and removed the shroud. Found the wires going to the reversing valve had come loose and dropped down touching the copper tubing of the compressor, melted the insulation and shorted out.

I fixed the wires and reattached them to the housing out of the way. Fixed the problem.

CJScepter · 06-11-2019, 10:40 PM

I replaced my reversing solenoid when the rear unit was putting out heat, cost about $35.00 I think. Mine would start off cooling just fine and then would drop out, go to heat and sometimes switch back to cool. It made a heck of a racket when it switched back and forth!

veraken · 06-13-2019, 08:50 AM

With the cost, and problems (especially the reversing valve), would you be better off just buying a Penguin A/C without heat pump and just use your furnace when needed?

vito.a · 06-13-2019, 11:00 AM

We also had a Dometic heat pump reversing valve fail. Some folks say you can apply a strong magnet to the reversing valve and get it to work, but it didn't work for me.

I emailed Dometic customer service and they gave me the part number for my unit.
I purchased a new reversing valve on eBay for $34.49. It takes about 15 min to install.
Dometic | 3310714005 | Penguin Reversing Valve Solenoid

As a side note, the older Dometic heat pumps were set up to operate normally in the heat mode and used the reversing valve to operate in cool mode, but the new systems are set up to operate normally in the cooling mode.

curtismb · 06-26-2019, 12:45 PM

Will be attempting to replace 6/27/19 after receiving ebay buy item today. Is there any special advice as to the installation. I will ensure all power is turned OFF and it looks like it will be difficult to pull the (white or clear) wire that connects to the absolute bottom of the circuit board. I plan to splice new wire to existing for that one but can easily get to the red connector on board.

vito.a · 06-26-2019, 06:52 PM

Just splice the new solenoid to the old wires. Use some good quality insulating splices. I use the ones with glue inside that are heat activated. Seals the splice completely.

jacwjames · 06-26-2019, 07:03 PM

While you have the AC shroud off take time to clean everything, use a compressor and air nozzle to blow everything out.

Also, the shroud over time becomes brittle. On mine the areas around the screws was cracked and eventually the shroud would have blown off eventually. I took the time to put 4-6 more screws around to help secure it.

curtismb · 06-27-2019, 11:17 AM

It worked! Thanks very much for everyone’s input-most appreciated.

hypoxia · 06-28-2019, 03:56 AM

Quote:

Originally Posted by vito.a

Some folks say you can apply a strong magnet to the reversing valve and get it to work, but it didn't work for me.

Vito, the magnet I use is a Kwikee step switch magnet. I removed the magnet from the housing, it is perhaps 5/16" Diameter and an inch or so long. It works with my heat pumps.