A/C operation question...not cooling

[Garypowell]

We have the typical (circa 2012) 15,000 BTU Dometic unit in the main room of the rig. It has worked well for our ownership since late 2012. So at least the 2 year Dometic warranty is up. But before I go with the extended warranty I want to see what the experts might think is wrong with the unit. It has the following characteristics:

1. Does not seem to cool....very little water coming off from it on the roof.

2. removed bonnet on roof and compressor is hotter than blazes....burned two of my fingers when I touched it to see if it is running.

3. The compressor is running.....well for the .5 seconds I could touch it I could feel the vibration.

4. All fans are running and moving air.

5. No heat is coming off of the unit on the roof....I had mentioned very little water. The front A/C puts out a moderate amount of heat which I think is normal.

6. Coils are clean and there is no frost on the inside coils. I did move the freeze sensor.

I know car and house units have sensors that shut the units off if there is no refrigerant pressure. Maybe because these units are sealed they don't have these.....but it would seem the compressor should not be running if they do have these sensors.....

so that is one of my questions.....will these units compressor run even though no refrigerant? maybe this is why it is so blazing hot!

And, of course, any suggestions for anything else I could check/do. I guess I was hoping the starting capacitor was blown....that I can handle myself.

Thanks all for what comments you can provide.

 

[Bob&Patty]

Gary, if the freon charge is OK then the low side (larger pipe) should be cold. The high side pipe (smaller one) should be hot. The evaporator coils should be cold to the touch. I don't know if these units have low pressure cut off switch/sensor or not. The system might have just enough freon to run the compressor but not cool. Short answer, it's probably low on freon and needs to be replaced.

 

[Garypowell]

Thanks Bob. Everything is the same "outside" temperature to the touch except for the compressor....which as I said burned my fingers when I touched it. I have turned it off and opened up the ductwork from back to front so at least the bedroom air can circulate around.

I had blocked the duckwork back to front so the bedroom air would only cool the bedroom and the living room unit would only work in the living room. It was a great solution, as it let each unit turn off and on as needed in its area, but also easy to remove the block in times like this.

I do have an extended warranty but I know it will be a battle. Just need to start the process next week.

Certainly if others have some wisdom please chime in.

Thanks,

 

[etcmss]

where is the block installed to separate the LR and bedroom flow?
Gary

 

[Garypowell]

I have dual duct system so I put one in the duct after the bath vent on the living room side. This way the bedroom a/c handles the bathroom. The other is on the other duct as it goes down to the living room.

Just drop rip the grating down (I have also put in adjustable vent grates) and I use 1/2 of a noodle to do most of the blocking and finish it with silver tape.

I also blocked the the end of each duct since it is my belief they are open.

 

[justafordguy]

The compressor will run even if all the freon leaks out. Mine did that a few months back and Domestic replaced it under warranty.

 

[Garypowell]

Thanks.....I thought that might be the case but nice to have confirmation. I'm going to call dometic this afternoon or tomorrow morning after the weekend Rush is over. The bedroom a/c is keeping us cool so no emergency.

That call will confirm the problem and make sure their new unit is a direct replacement. I know I am past the two warranty but sometimes with a nice conversation a miracle can happen.

Once I see what Dometic will do I'll get out my 5 year warranty and see what their provisions are. We bought the policy when we bought the rig and were a whisker away from bankruptcy (it was a fall back option if we lost the house) and could not afford to fix anything so it was a nice safety net. God has blessed and we are back on our feet again and have been talking about dropping the policy and getting the prorated cost back. Since a new a/c is in the $700 range with shipping we can us the refund to pay for it rather than be denied payment and waste several months in the process.

Or or it could be once I talk to the warranty people it is a straight forward process and we go that way.

I'll report back on how this works out.