Dometic Penguin AC issue, maybe?

[ajducote]

I have 3 Dometic Penguin a/c & heat pump systems on my roof. They all have a drian system that collects the water from the evaporator and drains it out the both sides into some pipes on my roof. It appears that my front A/C may have a leaking catch pan inside the unit. It is a plastic pan that the evaporator sits in. When water collects in the pan it is suppose to run out the side drains. But when I pour water directly into the pan, some of the water ends up inside the metal base unit of the AC. So if enough water collects there it eventually leaks into the coach. My question is, has anyone found a way short of replacing the whole AC unit, to fix this problem. It looks like it would be near impossible to remove the evaporator to get to the plastic pan. It may be possible if the whole thing was completely disassembled. The other thing to keep in mind, these units are almost 12 years old. So I wonder what the payoff would be in trying to fix 1 that old, versus just replacing it.

Comments welcomed.

[BenC]

Have you observed this problem/issue? I mean, have you actually had condensate leak into the coach interior, or is this only a concern at this time? Also, are you sure the drain lines are clear of cobb webs and debris? This is a common problem that results in excess water inside the roof unit base pan.

Something you need to be aware of about the Dometic system:
If the Dometic a/c's are original, you should have a 4-button Comfort Control Center (CCC for short) inside. Most converters used just one CCC to control all three or four rooftop units. The circuit boards inside each roof unit are specific to that CCC. These boards are no longer in production. Unless you have a separate CCC for each roof unit, changing one item in the system will require you to change the circuit board in all the other units you are not replacing, and update to a 5-button CCC for system compatibility. Also be aware, if you were to find boards that were supposed to be compatible with the 4-button CCC, there were 4 major revisions, and the clock speeds are not the same with all of the older "4-button system" units. Simply finding older components doesn't get someone out of changing all the boards. Just food for thought.

[HarborBus]

Ben, how do you clean out the drain lines? I was thinking air.

[ajducote]

Ben,

Thanks for the reply. Yes water has come into the coach. The lines are clear. I took the top of the off and poured water directly into the drip pan. Water flows easily thru both drain pipes. As I did this I watched and slowly water would seep into the metal pan. I was very careful to only get water into the drip pan. That's what makes me think the plastic drip pan might have a crack in it. And yes, all my AC units are original. The control unit only had 4 buttons.

So can I change the front AC, and the control unit, then put new circuit boards in the 2 other units? Or do I need to replace all 3 A/C's and the Control Center?
What are my options? I am leaving in 2 weeks for a 7 month, 8500 mile trip and I need to figure out what I need to do.

Thanks

[BenC]

So can I change the front AC, and the control unit, then put new circuit boards in the 2 other units? Or do I need to replace all 3 A/C's and the Control Center?
What are my options? I am leaving in 2 weeks for a 7 month, 8500 mile trip and I need to figure out what I need to do.

If you want to change the first AC, you simply need to order the CCC (Dometic PN: DC3109228001), and two of the new boards (Dometic PN: XXDC3311557000). Let me know if you have trouble getting these. If you do, I'll be happy to get some for you. The board update comes with the evaporator coil freeze protection thermistor, which the original AC did not have).

[tpr]

My last coach has three coleman airs and they worked like ice machines. The rear air would leak on high humidity days into the coach. The techs pulled up the unit to find the plastic connector from the pan to the drain line was cracked due to movement and road vibration. Replaced the fitting no more drips.

[dmatz]

My roof AC systems were leaking and I looked at the pans cleared the rain lines and all and they still leaked. I was told that the 4 bolts that hold them down can losen or the large o gasket can compress over time. Sure enough after checking them some were very loose. I tightend them up and the leaks stoped. Maybe it could be that simple.

[ajducote]

Thanks to everyone for your replies. I am sure that the leak is internal from the drip pan to the inside of the coach. I have been thinking for the last 2 years that at some point I would have to replace all 3 A/C units. So now is the time. I have had issues with the center air not working proiperly at times, and the rear air has trouble starting on occasion. So I have an appointment to get all 3 airs replaced next week. The bus will be 12 years old in May and little by little I am replacing any item that seems to be reaching the end of life. It appears that I will have this bus for a long time and I consider this a step in making it more reliable and enjoyable.

[BenC]

Sorry I missed the drain line question earlier. Yes, we normally use a shop air line with a nozzle and rubber tip on it to seat against the plastic hose most converters ran for the drains. Listening carefully, you will be able to hear when there is flow and no restriction. Be carefull not to pressurize the line to a full pressure if a bad restriction exists, as some of the fittings, which were originally intended only to prevent water leaking, not pressurization, may blow off. We have a 75 psi regulator set up for that use. Just some considerations.

[ajducote]

An update. I bit the bullet and had all 3 airs replaced with 15K BTU Dometic Penguin systems and a new 5 button controller. I had the work done at 1 of our sponsors, CoachWorx. Rick May and Ben Cummins were great. They got the work done on time and not a penny more then the quote they gave me. They had a little trouble with 1 wire and in no time figured it out. Also 1 unit was bad out of the box and they had an extra 1 on hand. SO that sure saved some time. Rick and Ben really know thier stuff. They are a great resource for us and they try real hard to make you happy. Oh yea, total cost, parts, labor and tax, just a touch over $3600.00. The new units cool great and are no where near as noisy as the old ones.