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urnmor · 08-13-2017, 12:59 PM

Our new Dometic AC is not blowing cold air. The fan works but unable to tell if the condenser is working. The unit has only been used once before in June and it worked fine. any advice is greatly appreciated

rodsterinfl · 08-13-2017, 01:13 PM

when you turn it on, listen for two distinct startup sounds- the fan (easy to tell sound) and compressor sound (might be heard easier outside). The fan is first usually.

urnmor · 08-13-2017, 01:42 PM

I believe the compressor is working but not completely sure. If the compressor is working do you have any suggestions. If it is not do you have any recommendations to troubleshootThanks

rodsterinfl · 08-13-2017, 01:44 PM

How long have you let it run? Is the thermostat on cool and a low temp? The fan is a blowing sound and the compressor is a purring sound. Usually the compressor is heard outside with blow sound. Sometimes it takes a while for the air to start cooling. Are you running it on the 30amp power?

OTRA15 · 08-13-2017, 01:47 PM

Using a digital meat thermometer, with a small metal end, test the air temp at the A/C intake, and also at the discharge. You should see a Delta temp drop of about 20 degrees F. As/if the trailer starts to cool down, the discharge air should also get colder, maintaining the same 20F Delta. Quantifying the temps will help with the diagnosis IMO.

Most hardware stores sell these thermometers for about $15 to $20. Taylor makes one. Similar to the ones used by HVAC contractors.

I would also do a hard reboot of your stat, which the manual for you new AC should describe. This may be a thermostat problem IMO.

"Dometic Stat reboot" search results:

https://www.google.com/search?q=dome...=airforums.com

Is the dealer/contractor who installed the new A/C nearby? Still under warranty? Back in June, did you run the new A/C for a while, and it worked OK? In other words, did your old stat recognize the new A/C? Do you recall if the installer had to do a hard reboot of the stat at the time?

If you have used the heat since June, did the furnace work OK (indicating that the stat was functioning correctly)?

Good luck!

Peter

urnmor · 08-13-2017, 02:33 PM

The temp coming from the AC is 84 degrees the same as the outdoors in fact outside is a few degrees cooler. Also I tried the heat pump and set it at 88 and it did not come on. The AC worked fine in June.
One more thing my surge protector turn green but when I connected the electrical code it stayed green but the red light blink

OTRA15 · 08-13-2017, 07:22 PM

Did you try the hard re-boot of the thermostat, as mentioned in my earlier comment?

Tomorrow is the start of the business week. Probably a good idea to call as many people as you can, if the unit is under warranty. Also Dometic's toll-free number.

You will have to check the surge protector's manual to figure out the colors/blinks/codes. If you post the mfg. and model number, someone here may be able to help on this.

Good luck!

Peter

**wulfraat** · 08-13-2017, 10:05 PM

Quote:

Originally Posted by urnmor

Our new Dometic AC is not blowing cold air. The fan works but unable to tell if the condenser is working. The unit has only been used once before in June and it worked fine. any advice is greatly appreciated

For what it is worth the new 15k dometic AC on my 2017 30' lasted 6 service days and then died (stopped producing cold air). It lost its freon and was replaced under warrantee.

- There were no errors on the control center
- The fan would come in and the compressor would kick in - so everything 'appeared' to be 'working'
- With an ammeter I verified that the compressor was only drawing 8amps vs 12-13 - which indicated reduced load in the cooling system - i.e. refrigerant leak!
- Obviously no cold air was produced and no warm air was produced when in heat pump mode
- no condensation water was present in the wheel well drain

Tech verified what I knew was the issue - freon leak.

Replaced with a new unit and we were back in action.

OTRA15 · 08-14-2017, 03:29 AM

Good call -- voting for a freon leak too. Seems to me other threads have reported similar in new-ish units:

https://www.google.com/search?q=freo...=airforums.com

Good luck!

urnmor · 08-14-2017, 07:15 AM

My thanks to all of you for your responses. Unfortunately it is still not working. I have done a reset and that did not work. I do not believe the condenser is working as the heat pump also does not work. So I am wondering if the connection is loose at the unit. I checked the connection at the thermostat and it was fine. I am not sure how to check it at the unit. Any suggestions on to to check it is greatly appreciated. If it is not the connection then it is either the Freon or a bad unit. I have a call to Colonial as it should still be under warranty

OTRA15 · 08-14-2017, 07:23 AM

Thanks for the update, please let us know how it all plays out.

Thanks,

Peter

**wulfraat** · 08-14-2017, 07:33 AM

Your next steps in troubleshooting is to get up on the roof. Remove the plastic AC shroud/cover there are four screws holding it down. Inspect the pan for an oily substance which would be indicative of a Freon leak.

You will not always see an oily substance if there is a leak.

The next thing to do while you are on the roof use a small ammeter and put the clamp around the Black wire going to the compressor motor. Go back down into the unit then turn on the AC and then go back up onto the roof. Measure how many amps the compressor is drawing. If it's anything less than 12 then again you likely have lost your Freon.

urnmor · 08-14-2017, 09:36 AM

fortunately it is still under warranty so I spoke to Tony at Colonial and they will look at it on Wednesday

**wulfraat** · 08-14-2017, 09:43 AM

There you go. Have someone else climb on the roof and figure it out

Glad they could get you in so quickly

zapper · 08-14-2017, 02:33 PM

Hmmm seems to be a flurry of Dometic AC failures after 6 mo .in new AS's. I too had my rear AC 1,500 BTU go bye-bye in 6 mo. it showed all of the same symptoms described above: no cool air, fan on etc, etc. It was a little difficult at first to isolate the AC problem as both AC units share all 10 ceiling ducts. At the thermostat I was able to turn off the front AC (zone 1) and then turn on the rear AC and I could immediately tell there was no cooling nor heating just fan noise. bty later on the Dometic Thermostat registered an Error code in Zone 2, I believe it was 71 but not sure looked it up Dometic Manual it said power disconnect from main board.

Took it in to the nearest AS dealer to where we were in Montana which happen to be Colorado. They confirmed the unit no workie. They also stated that the newer units used ammonia and not Freon. Hmmmm. Really? I wonder what he was smok'in? lol

It's in the LA AS Dealer shop now for replacement.

urnmor · 08-14-2017, 05:21 PM

Well my family deserted me on this camping trip. They all went home to the AC but not is all lost as I sit here sipping some really fine rum and listening to some great jazz. Just saying sometimes you can you make a silk purse out of a sow ears and don't forget life is to short not to have fun

OTRA15 · 08-14-2017, 06:18 PM

Well said!

Kyet · 08-15-2017, 05:36 AM

My rear AC unit does not come on at all. Even with the override switch. We were on a 30 amp for our testing evening and completely missed testing that unit. It's a 2018. Calling the shop today

mikesSE · 08-15-2017, 05:45 AM

Bad Dometic unit.June'17 ,I bought a new Dometic Penquin 13.5k.It ran on start-up,one month later on our trip to Maine,it would not cool.Dometic replaced the unit free of charge so you know that they knew that they had a problem with their units.Southland RV in Georgia did the remove/replace quickly,with no extra charge.I should have bought a Coleman,but freaked out about the lack of a drain kit to keep the condensate water off of the roof.Tell Dometic directly about your replacement/problem.

Biker · 08-15-2017, 06:01 AM

Quote:

Originally Posted by urnmor

fortunately it is still under warranty so I spoke to Tony at Colonial and they will look at it on Wednesday

The AC in our new 23FB failed as well. It was replaced by Colonial in July. So far so good. Took about 2 weeks for them to get the new unit in and install it.