No Power to HVAC

derekaj · 07-20-2020, 06:33 PM

Newbie here. Took delivery of a new 2019 Cougar 29RDBWE three weeks ago. Haven't had it out yet as I've been waiting for my Anderson hitch. I've been familiarizing myself with the coach in the meantime and have encountered an issue with power to the HVAC system. I've got it connected to a 20 amp circuit from my home. Everything's worked fine until a couple days ago when the HVAC wouldn't power on whether in Fan, Cool, or Heat mode. I disconnected from power, disconnected the battery, and hit the reset button on the BCM, none of which corrected the problem. I let it sit for the night, came back the next morning and everything powered on fine. Now, a day later I have the same issue. No power in any mode. I went through the same disconnect and reset exercise mentioned above, again with no luck. So at the moment HVAC is completely dead again. I should mention I tested all circuits, microwave, and refrigerator and all are working fine.

Looking for advice on a possible solution or more in depth troubleshooting measures I could take. Thanks in advance!

**flybouy** · 07-20-2020, 06:51 PM

Are you sure it's a 20 amp? One of the three blades has a sideways slot as well as the vertical? You can not run the a/c on a 15 Amp house outlet.

derekaj · 07-20-2020, 07:16 PM

Hey flybouy thanks for your input. Well I was mistaken...it is attached to a 15 amp circuit, not 20. I previously had my parent's motor home stored in my driveway and we had no issue running it's AC off that circuit, so I didn't think that would be the problem. I also ran my new Cougar's AC several times on the circuit with no issue, until now of course. I guess the first thing I should do is hook it up to my generator's 30 amp circuit to see if the issue resolves.

I'm skeptical that's the problem though because I'm also not getting power when selecting Fan or Heat mode.

bobbecky · 07-20-2020, 08:09 PM

You’ve tripped a breaker somewhere, most likely in the house. If that 15 amp outlet was outside, you may have tripped the GFI to that outlet. You also could check the breaker in the trailer panel. Any breaker to the trailer or A/C that is tripped will not allow it to work. Don’t risk damage to your A/C by running it on too small a circuit.

derekaj · 07-20-2020, 08:18 PM

Thanks for your help bobbecky. The house breaker's fine because I've still got power to everything else in the trailer. I did check the A/C breaker in the trailer and it's OK too.

Good advice on not running the A/C on the 15 amp circuit. Even though I've done it in the past doesn't mean it's a good idea. Thanks!

travelin texans · 07-20-2020, 09:43 PM

If you're not getting heat when switching at the tstat then check your batteries, the furnace only operates on 12 volt & battery power is needed to power the tstat. Check the factory battery disconnect, if it's disconnected your batteries will not charge while plugged in. Also if tripping the shore power breaker your batteries may be weak even if the disconnect is connected.

**flybouy** · 07-21-2020, 05:35 AM

What btu is the a/c in this new camper? There are several variables why it "did work" and why it won't work now. Bottom line, it's not a good idea to run an a/c unit on a 15 Amp circuit.

Many years ago BIN bought a 30' Jayco. 30 Amp and he plugged into a garage 15 Amp outlet that was located under the main breaker panel in his garage. He used one of those $3 "hockey puck" adapters (he's cheap).

He cooled down the fridge on electric (did I mention he's cheap?) and when hid DW started to load it turned on the a/c. Breaker tripped. He reset it several times. Fridge stopped working. Back to dealer new control board on the fridge. Next weekend repeat and again new board under warranty. Third weekend and dealer said no warranty, you owe us money. He ended up paying for board #3.

He called me complaining and I explained again, yes, I told him the first time that he caused the issue, and he finally got it. He asked to install a 30 Amp in the garage. When I did I pulled out that 15 Amp receptacle and #14 wire and both were heat damaged. Builder didn't use screw on wire terminal outlets but the cheaper "push in". I explained to him that if that panel had been farther away his fire insure may have been paying for the repairs.

The point of this story is to convey that doing this can lead to issues and when someone with knowledge and training gives you advice you may want to consider it and think that you can "get by" by taking a "cheaper" route.

Customer1 · 07-21-2020, 04:28 PM

The furnace operates on 12vdc and propane.

The A/C operates on 12vdc and 120vac

What they have in common is the thermostat and 12vdc so the problem is likely one of those two things. The 12vdc is easy to verify.

derekaj · 07-22-2020, 05:34 PM

Finally got the generator setup today and hooked it up to the RV. Tested all HVAC functions several times throughout the day and everything worked flawlessly. Apparently it didn't like the 15 amp circuit I had it on, but the fact that it worked previously (although intermittently) threw me off. Thanks to all who provided guidance on this issue.

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