Community Forums

Tahoejeep · 07-28-2017, 09:51 AM

My rear AC/heat pump unit has failed. I know that these are throw-away units. The compressor does not run and as far as I can tell, the start capacitor is OK. The fan motor runs. I called and got what I think is a good price for a new unit from PPL Motorhomes out of Texas. To replace one unit I need a conversion kit to adopt the new unit to the old 5 button thermostat.

What do you think? Should I go ahead and replace both units at the same time and get a new thermostat, too, or just replace the one failed unit? I am thinking I would save myself $200 each by not getting the heat pump which I rarely use. I'm not made of money. By any chance are the new units quieter than my 2003 model?

How easy are these units to replace yourself? I am mechanically and electrically inclined.

Thanks! Joel

Sunny1 · 07-28-2017, 11:07 AM

Joe,
I'm in the process of replacing both of my Coleman A/C units. One would just blow ambient air, and I even replaced the capacitors and that didn't fix it, so being that they are the original 19 year old units I decided to replace both because I didn't want to be camping somewhere and have the old one fail. I replaced the first one, and it was actually fairly easy. The most difficult part was getting the new AC up on the roof. I used a Bobcat to lift it up, and that made things much easier. The most time consuming part was sealing off the inflow/outflow air from each other. I took my time and used foil tape. I still have to do the other unit, and I'm thinking that's going to get done next week since I have the week off. I also think since I now know what I'm doing it will probably take me less than 2 hours to replace the second one.

I don't know if your units are Coleman, but mine are, and I went on the Airexcel website and plugged in my old model numbers and it told me the replacement model since my old AC units models had changed. I also needed to replace the ceiling assembly since the old ceiling assembly 4 holes wouldn't match the new unit. I called Airexcel and confirmed that it would really be as simple as removing my old unit and putting in the new one, and they said yes, that the new unit would be compatible with my existing thermostat (I have a ducted system), and it was, all I had to do was unplug the old AC wiring from the control unit and plug in the new AC wiring. Finished the install and it worked like a champ when I turned it in. I Loved hearing the sound of that compressor turning on!

I was going to order from PPL as well, but called two local RV dealers parts depts and asked about the pricing for the models I needed, and one of them was competitive with PPL, and they gave me a 15% military veteran discount. It may be worth your while to check with any local dealers who are close to you and ask if they'll match PPL's price.

Anyways, This ended up being a bit long winded. I'd replace both, do it yourself and save $$$, and call some local dealers to get quotes.

Kiawah · 07-28-2017, 11:13 AM

Quote:

Originally Posted by Tahoejeep

My rear AC/heat pump unit has failed. I know that these are throw-away units. The compressor does not run and as far as I can tell, the start capacitor is OK. The fan motor runs. I called and got what I think is a good price for a new unit from PPL Motorhomes out of Texas. To replace one unit I need a conversion kit to adopt the new unit to the old 5 button thermostat.

What do you think? Should I go ahead and replace both units at the same time and get a new thermostat, too, or just replace the one failed unit? I am thinking I would save myself $200 each by not getting the heat pump which I rarely use. I'm not made of money. By any chance are the new units quieter than my 2003 model?

How easy are these units to replace yourself? I am mechanically and electrically inclined.

Thanks! Joel

First, I'd swap the thermostats to be sure that it's the AC unit, and not a bad thermostat.

Assuming it is indeed the AC unit, then personally I'd replace both, given that they are both already 15 years old. You're going to need to get help to lift the new one up and get the old ones down, so might as well do both at the same time and be done with it. The 2nd one will be substantially easier once you figure out everything needed for the first one.

Whether you choose heatpump or not is a personal decision. I have heatpumps on mine, but only occasionally use them, given that the fireplace and small heat cube are substantially quieter (plus I'm saving wear and tear on the heatpump compressor and fans). If I were paying for electricity, then that may be a different story.

I don't know what incremental resale value would be on having heatpumps vs non-heatpumps.

OLYLEN · 07-28-2017, 11:33 AM

Sounds like $$$ is the key so only you can make the decision. Three options and a forth heat pump option. One unit and conversion for the thermostat. Both units and conversion for thermostat. Both units and a new modern thermostat. And another factor, how long will you keep the RV. Not a hard job replacing just need two men for lifting. Get a new gasket for the A/C. Good luck.

LEN

vsheetz · 07-28-2017, 11:53 AM

At that age, I'd probably replace both. New thermostat. Leave out the heat pump if rarely used (we seldom use ours).

The worst part of swapping them out is getting the new units to the roof. Sliding / pulling them up a extension ladder is one way.

I'd get a price from a couple places to do the swap. Maybe a mobile tech with you helping. Then decide if to DIY or hire it out.

bruceisla · 07-28-2017, 12:19 PM

I did this last year on our Newmar with 3 Dometic units. I pulled all 3 up an extension ladder. 1 each day ... I am 72, 240 LB., 6'3" tall, decent shape. Not much fun but can be done. My old units were running but probably near end of life. I chose to replace all 3 and install the new thermostat. I am happy with my decision !!!

As for the removal/install, although it only takes an hour or so, allow an extra hour for cleaning the roof surface and for proper re-taping of the airbox and associated ductwork. You'll need about 3 rolls of Reflectix metal tape (HomeDepot /Lowes) for 2 units.

Reflectix 2 in. x 30 ft. Reflective Foil Tape-FT210 - The Home Depot

BTW, if you have a HydroHot, it may have a Dometic controller that will need to match the new thermostat (an extra $100).

My parts list included:
3 - Ducted 15K Dometic Brisk II w/heatpumps and controllers;
1 - CCC2 Thermostat;
1 - Dometic standalone controller to match thermostat (HydroHot);
8 - Rolls of Reflectix tape;
1 - Acetone (to clean roof).

Tahoejeep · 07-28-2017, 09:16 PM

Thanks for the replies. I'm leaning towards two new units w/o heat pump. I forgot that a little cube heater would work fine in place of the heat pumps and be much quieter! I would need to verify a new thermostat will run the existing gas furnace, which we have used quite a bit when dry camping. I have a son-in-law with an ASV so getting the units on the roof should go fine. Time to hit Youtube for the finer points to replacing the ACs.

Joel

bruceisla · 07-29-2017, 03:01 AM

Quote:

Originally Posted by Tahoejeep

Thanks for the replies. I'm leaning towards two new units w/o heat pump. I forgot that a little cube heater would work fine in place of the heat pumps and be much quieter! I would need to verify a new thermostat will run the existing gas furnace, which we have used quite a bit when dry camping. I have a son-in-law with an ASV so getting the units on the roof should go fine. Time to hit Youtube for the finer points to replacing the ACs.

Joel

The new CCC2 thermostat will control your furnace just like the 5-button.

Assuming your rooftop units are mounted with long bolts from the bottom, when you replace the units the torque spec is listed in the install spec (it's something like 50 INCH lbs). If you don't have a torque wrench, 50 INCH lbs. is about what an average person can generate with one hand on a screwdriver/nut driver. Don't overtighten.

BTW, the average A/C unit lasts about 9 years.

veraken · 07-29-2017, 05:13 AM

Here are 2 videos from the vintage RV forum on replacing AC units. It may give you some ideas.

https://youtu.be/mT2Doa43XEQ

https://youtu.be/ejbW8oSZV_w

I didn't replace my AC units, but I did replace my thermostat with the CCC2. My thermostat was on the outside wall and when the heat from the wall met the cool inside air, I had moisture build up behind the thermostat which shorted out the PC board in the thermostat. To solve this, I sprayed low expansion foam into the wiring cavity behind the thermostat and placed a small piece of foam between the PC board and the wall.

hypoxia · 07-29-2017, 05:16 AM

[QUOTE=Tahoejeep;3723028]The compressor does not run and as far as I can tell, the start capacitor is OK. /QUOTE]

I'm going to swim upstream from the advice given.

I would make sure it is not the capacator, PTCR or something simple.

IMHO, Most of these units are replaced due to frustration when the problem is a simple repair.

A meter to check voltage, capacitance, amps, etc. is not expensive.

cruzbill · 07-29-2017, 09:38 AM

Bruce, Can you tell me more about the control box you had to add so your Hydro Hot would work? Our Beaver is in the shop (1 month now) for a rear AC replacement.
Our old 5 button tstat had 2 zones (zone 2 &3). Had to replace the 5-button with the new CCC2 tstat.

Zone 3 did not show up when I went to pick up the MH. Zone 2 furnace (Aqua Hot) worked fine.

Shop called back and said to get zone 3 to work I need a new 'board' and 2 hrs labor. This is getting a bit ridiculous. They first tried to rewire the AC to work with the old tstat, then said we need the CCC2, now this 'separate' 'board'. Ours has an Aqua-Hot. 2 rooftop AC/heat pumps. 3 zones, two tstats.

How much more complicated can this get?

bruceisla · 07-29-2017, 03:13 PM

Quote:

Originally Posted by cruzbill

Bruce, Can you tell me more about the control box you had to add so your Hydro Hot would work? Our Beaver is in the shop (1 month now) for a rear AC replacement.
Our old 5 button tstat had 2 zones (zone 2 &3). Had to replace the 5-button with the new CCC2 tstat.

Zone 3 did not show up when I went to pick up the MH. Zone 2 furnace (Aqua Hot) worked fine.

Shop called back and said to get zone 3 to work I need a new 'board' and 2 hrs labor. This is getting a bit ridiculous. They first tried to rewire the AC to work with the old tstat, then said we need the CCC2, now this 'separate' 'board'. Ours has an Aqua-Hot. 2 rooftop AC/heat pumps. 3 zones, two tstats.

How much more complicated can this get?

It is a bit complicated.

I have 3 top units and a HydroHot. The HydroHot is controlled by a Dometic Control Unit that would ordinarily control an A/C. It is in the daisy chain along with the A/C units. Mine are Zone 1 (A/C Front), Zone 2 (A/C Mid), Zone 3 (HydroHot), Zone 4 (Bedroom A/C). I also have 4 remote wall sensors. The hall bath sensor is for the HydroHot ... the Dometic controller is under the bathroom sink on the wall.

The old 5-button thermostat and the new CCC2 "see" the controller as Zone 3 (assuming bit switches are correct). If you have a CCC2, you need a matching controller.

Below is a match for the CCC2 .... basically, it is a Penguin II board in a metal box. P/N 3312020. If I remember correctly, the freeze sensor (included with box) MUST be plugged in (just coil it up).
Dometic CCC2 Multi-Zone Comfort Control Center II Board Kit - Circuit Boards - RV Appliances

If yours works like mine, the trick is finding the controller. Mine was on the wall behind the sink drain pipe .... not obvious. The room sensor is up under the mirrored cabinet above the sink.

UPDATE: Upon rereading your question, I'm not sure which of your A/Cs were replaced and what model/part number was used.

The problem is:
* New Dometic top units require a CCC2 or they need a conversion board to work with a 5- button.

cruzbill · 07-30-2017, 08:59 AM

Our Beaver, two AC, two 5 button tstats, aquahot. Rear AC failed. Shop replaced w/new and replaced rear 5 button w/CCC2. Front AC still has 5 button tstat. I tested rear AC and all works fine, except that there is no 'zone 3' on the ccc2 tstat. I thought shop just had to flip DIP switch on rear AC to enable zone 3. I guess I was wrong, they said they needed to order a 'board' to make it work. I'm hoping that's the 'board kit' you mention. Shop said the board was not located in the roof AC. Zone 2 runs rear AC and vanity aqua hot. Zone 3 runs bedroom aqua hot. Frustrated, am calling Dometic Mon AM.

Thanks for the help!

litlgeezer · 07-30-2017, 09:24 AM

I just had a local shop replace one of two Carrier units about a week ago. It was not very difficult for three techs and took them about 45 minutes. We were away from home (and tools) and in 110F heat index days, so I pretty much had to use the local shop. However, they knew what to do and were very courteous.

I think that I would have preferred replacing with a new Carrier. My other Carrier is still working great-why bother with something not broke? If it breaks down and I am home, I may do it myself. I have the know-how, finding a couple of young strong backs to help me would be my problem.