Need help diagnosing roof A/C

[2_many_2]

On Edit: Problem successfully diagnosed, last post here.

My roof air Conditioner / Heat Pump does not cool or heat. It is a three year old TT with a Dometic low profile Penguin II High Output 15K BTU with heat pump. Model number 651816C851J0. The thermostat is the CCC II digital.

The fan and compressor start and run, both start and run capacitors for the compressor both test within spec. The sticker on the compressor reads, RLA cool 13.4 and RLA 12.2 heat.

The compressor pulls 10.5 amps per my clamp over meter on both cooling and heat pump after running 30 minutes on each. My supply voltage maintains 115 or more.

There are slight oil stains on some of the solder joints of the Freon tubing, but not much, (normal?)

Manufacturing stickers on the AC frame under the cover state the manufacture date is 2012. Also there are several stickers that say “Made in China” 😞

Seems like a short service life as compared to the other American made AC units I have had.

From my research, it looks like I have lost the Freon charge? Is there anything else I should try before I replace the unit?

Thank you

[jerryjay11]

Your compressor is running and not cooling and with the oil at the solder joint it tells me you have a refrigerant leak. The oil is refrigerant oil. Take it from me as a retired HVAC technician who has repaired many AC units. An RV AC/Heat pump is built the same as many window units I've worked on.

Amperage does't matter since you know the compressor is running. If it's running it should cool if it has refrigerant, period.

A leak repair cost would depend on who does it, but at least $300.00 and could be up to $600.00.

[2_many_2]

Doug,

No offence taken, that made me laugh because you are right, I know just enough to be dangerous. Thank you for taking the time to offer your expert guidance and diagnosis.

Thank you to everyone that responded, I learned a little bit from each post that either will help me now or in the future.

Also, my unit is out of warranty, I did contact Dometic support and they said my unit was not one of the ones in the bad batch a few years ago.

I am very disappointed that Dometic went to China for this AC, I have had two before (Carrier and Dometic) that were still working after 10 and 20 years. The cost of a new unit is about $1200, I don't mind the cost so much, I just did not want to replace it because of some issue I was not aware of and later find out it was a ten dollar fix :B

I wanted to bring closure to this thread as so many OP’s ask for help and then disappear.
Thanks again and happy camping.........

PS: Problem solved in one day, you can't beat that! :B

[dougrainer]

2 many 2 wrote:
The output temp of the air is within one degree of ambient on both cool and heat.

BUT, This time I did all the testing over again using shore power, last time I used my generator just to exercise it.

On shore power the compressor only had a draw of 7.2 on cool and heat! After check and re-check I went back to generator power and got the original readings of 10.5 :@

I also used two different meters just to be sure. My volts on shore power held 115 and the ambient temp was 60 degrees, amp draw only 7.2, should have been almost 10.

My guess is that testing on the generator was not the best idea due to variances in voltage. And that the shore power reading is the correct one. So is 7.2 amp compressor draw low enough to indicate a Freon leak?

Thank you

I have NEVER seen a variance due to Gen versus shore Power. Yes, 7.2 would indicate NO coolant. No offense, but you really do not know what you are doing. You have just enough knowledge to get almost the complete picture. But, you got there. You have a BAD leaking unit. Replace it. Doug

[wa8yxm]

Well my first thought would be loss of refrigerant but you eliminated that (you said 10.5 amps) if that were the case you'd be seeing more like 5 or less. Though. 10.5 is a bit lower (What does the sticker say the current draw should be) Partial refrigerant loss may be an issue. This takes professional help to fix.

Have you inspected the Condenser/evaporator on the OUTSIDE?

Short but true story, I have A/C only, not heat pump so that coil is the condenser always on mine.. Well the A/C started tripping the breaker.

I checked and current was in excess of 20 amps when CLICK

Went up on the roof and the dang thing was clogged with cottonwood seeds.

Removed same, and 13.5 Amps solid.. Just like the sticker says.

[2_many_2]

The output temp of the air is within one degree of ambient on both cool and heat.

BUT, This time I did all the testing over again using shore power, last time I used my generator just to exercise it.

On shore power the compressor only had a draw of 7.2 on cool and heat! After check and re-check I went back to generator power and got the original readings of 10.5 :@

I also used two different meters just to be sure. My volts on shore power held 115 and the ambient temp was 60 degrees, amp draw only 7.2, should have been almost 10.

My guess is that testing on the generator was not the best idea due to variances in voltage. And that the shore power reading is the correct one. So is 7.2 amp compressor draw low enough to indicate a Freon leak?

Thank you

[dougrainer]

The amp draw shows FULL 410 coolant. You do NOT have a low charge. The unit should be cooling. What is the Output temp of the air? Doug

[dkreuzen]

Did you try calling Dometic support?
I have a friend that has had two of these replaced on a 2015 model.

[2_many_2]

I am reading the amp draw at the compressor, 10.5 at 70 degrees ambient temp.
The fan draws 2.6 amps on “High” speed.
For a total of 13.1 amps.
The Dometic specifications sticker reads "FAN FLA 2.6"

Thank you to everyone for the replies, still scratching my head :h

[dougrainer]

1. There is no recall on Dometic AC/HP units
2. The AMP draw is temp corrected. That means that the 13.4 Cooling draw is based on 95 degree ambient. You subtract 1 amp for each 10 degree drop in Ambient to get the correct amp draw. IE, It is 75 degrees ambient, your compressor amp draw should be 11.4 amps.
3. Are you reading the Compressor AT the compressor? Where are you taking your amp draw? Because on the wrong wire you will read both Fan and Compressor. Doug

[newman_fulltime]

There is a recall I believe on those units from the freon leaking out

[ScottG]

A slight oily residue at the solder joints may just be left over flux from the original build.
If the compressor is running then the caps are good.
Probably time to get it looked at by a pro. I would not use a RV shop, they'll probably just automatically tell you to replace it.

[Mandalay_Parr]

I would have an AC service guy look at it.
They can troubleshoot and add ports and freon if necessary.
Might also get some help from Dometic.

[DancinCampers]

Oil at the solder joints is not good.

When the unit is running, touch the hi side copper tube leaving the compressor. It should be hot.

[Old-Biscuit]

Fan runs
Compressor runs

Air flows out of ducts?

Air is not cool when on AC or hot when on Heat pump?

Then you have a leak and all freon is gone.

Cheaper to replace unit then it would be to have tech locate leak, fix leak, add service valves, add freon