Community Forums

rvfoo · 08-18-2016, 11:17 AM

Our 10 year old Dometic Duo-Therm 13.5K A/C unit just started to give up the ghost. When running fan-only, it's quiet and fine. As soon as I turn on the A/C ("cool"), it starts banging and carrying on as well as the my electrical meter drops from 120v to near 0v. A shop nearby said that the compressor is going or shot and that replacing the unit is the only option.

I've heard good things about the Coleman Mach 15 and understand that it should be a drop-in to the same 14x14 opening. I then saw threads that the thermostat would need to be changed. Some threads talked about changing the board or something for the rear A/C unit. In our coach, each A/C has its own thermostat so I should be safe to just replace the one, right?

Is there any other reason that I would want to stay with Dometic?
Are the Coleman's really better than the Dometics or is it a wash?

Thanks

RV Wizard · 08-18-2016, 03:41 PM

Hello and

We are glad to have you join us here and we look forward to reading of your adventures and experiences. I am sure you will enjoy our website and forums. Good luck, stay safe and keep us posted.

Today I think the comparison between the two is a wash and you will only have to replace the one. If you stay with Dometic, you will only have to replace the top unit on the roof. Reuse the ceiling assembly, control box and thermostat is all are working properly.

Old Scout · 08-18-2016, 03:56 PM

Just my opinion but suspect you will get a whole new set of issues with a Colman--not better, not worse, just different. If your other unit is also 10 years old, then 2 things: 1--its probably on its last leg too; and 2--even though they are both Dometic, comm protocols and motherboard designs have changed over the years so your 10-year old unit probably wont talk to the new unit without a motherbrd swap-out. PPL RV sales and parts in Houston is a good place to research all this--pretty good prices too. Just get the serial numbers off the two old units, then they can tell you whether the new unit will be compatible.

TQ60 · 08-18-2016, 08:54 PM

Thermostat may be married to the unit or generic.

If a dometic thermostat with the phone wire connection and either 4 or 5 button it will not work on the Coleman.
Also check the wiring before doing anything else.

The compressor does not like low voltage and a poor connection will result in low voltage condition.

Check voltage at pedestal when running then if low fire up genny as the pedestal may be bad.

rvfoo · 08-19-2016, 05:28 AM

I neglected to mention in my original post that the front and rear A/C units have their own thermostats. The link below is the same thermostat(s) that I have. Would I be correct in assuming that I could change one without impacting the other. I am looking more closely at the Dometic replacements now. It seems that the Brisk Air II is the new model.

https://www.amazon.com/Dometic-31069.../dp/B004MXN71U

TQ60 · 08-19-2016, 07:43 AM

Please contact dometic via their Web page as they seem (in the past) to be very helpfull.

Having the full model numbers allows them to confirm exactly what yiu have to better provide replacements.

There also has been a few not so good posts regarding the brisk units as not being domestic and maybe quality concerns.

The penguins also may have some issues so as always confirm the details.

Another note is newer units have much better operating performance resulting in lesser energy demands.

The newer 15 KBTU units often draw less power than the older 13.5 KBTU units and given it is not that much more cooling every little bit helps.

Consider that option as well.

After you decide the specific units you want post here as many have been down same road and could give their opinion as well....Just in case