Roof Air Conditoner Doesn't Work: Replacement suggestions?

aaron7 · July 15, 2013, 07:51 AM

AC unit on our 84 Mallard is original and only the fan works; won't kick on when set to AC so I'm guessing she's toast.

Called many places and was told the old R22 can't be refilled without a lot of trouble (welding in a fill) and it would cost as much as a new unit.

Our RV is under 30' (embarassing that I haven't measured it yet!) and the stock unit is a Duo-Therm Rotary XL either 558 or 578 series. I have the manual but haven't found the number on the unit itself yet.

Anyways, what is a good new replacement?

I was eyeing this one: http://www.rvupgradestore.com/Advent-Air-Conditioner-p/77-9114.htm

Thoughts?

pvoth1111 · July 15, 2013, 08:14 AM

Try Ebay...

M & J · July 15, 2013, 09:32 AM

And from the ad, it appears that price is for the rooftop unit only. The ceiling Assembly is an additional $76 for the non-ducted version.

pvoth1111 · July 15, 2013, 09:48 AM

I would confirm the old one is dead...if the fan works and it don't cool...start with the T-stat does the compressor run??? take the cover off....maybe there is a burnt wire.....don't get shocked....is there oil on any of then lines....no oil no leaks....could be a capacitor....even the compressor can be changed out...find a refrigeration guy instead of a a/c guy....ask you favorite food place who works on their coolers
these a/c's are super simple can always be repaired.....every part is available...and there is only like ten wires max

or buy the ebay thing and reuse your inside vent....or build one out of something... with duct work and lots of adjustable vents

HandyDan · July 15, 2013, 10:48 AM

Before you junk it, try this website: http://2manytoyz.com/air.html Although it talks about a Coleman A/C, they are all pretty much the same.
Dan

Madathlon · July 15, 2013, 11:48 AM

If you need to replace it, you might want to consider a heat pump unit that cool and heats in one unit, this will save you propane on those cold morning and keep you comfortable on those hot summer days.

Myself have just order this unit.

http://www.adventurerv.net/coleman-hp2-heat-pump-15000-btu-roof-air-conditioner-complete-p-1380.html

Have a great day

DaveVA78Chieftain · July 15, 2013, 12:09 PM

Just a thought. Had to replace the start and run capacitors on my coleman due to age. You might want to look and see if they have started to bulge out of their cases. Simple fix less than $35 total.

Dave

M & J · July 15, 2013, 01:50 PM

I think that's what Handy Dan was referring to in his post and link. We have a PTAC unit in our sun room home addition and it began to hum loudly several times before kicking in. I replaced the starter capacitor for the compressor and it was better, but would still have a hard time starting. I then added a "booster" or "jump start" capacitor in addition to the regular one and the problem was taken care of.

The interesting thing about the original post is that he doesn't say it just hums or tries to start. It simply doesn't run. So I was thinking about a contactor or relay being defective. But these starter caps are cheap and very easy to install as a first step instead of spending hundreds on a new unit.

aaron7 · July 19, 2013, 06:35 AM

Thanks for all the repair ideas! Had written this one off. I'll definitely look into the capacitors as they're 30 years old and I know all about replacing them in old electronics!

If that doesn't fix it however, what brands or models have people had the best luck with? That's more what I meant by the first post I suppose!

aaron7 · July 22, 2013, 07:53 AM

Inside the cover there were three capacitors; one black Mallory brand (tested on spec), one oval tall metal one (tested perfectly), and one round tall metal one (TOTALLY DEAD!!!)

My dad has one on order for $14 shipped.

Here's hoping!!

Oz · July 22, 2013, 07:38 PM

Well... wouldn't that be awesome to have a perfectly working roof AC for a $14 part!

JDxeper · July 22, 2013, 08:14 PM

Can you come and fix my AC on the 45 year old F-17 the 68 winne? Hope it works for you .

DaveVA78Chieftain · July 22, 2013, 08:22 PM

Will not suprise me if it fixes it. I had the same thing happen to me too.

aaron7 · July 23, 2013, 06:19 AM

Makes total sense! Same as any 20+ year old electronics, oil-filled capacitors leak out and go out or tolerance. That's why so many of those old 70's stereos sound so bad when you crank em! Now add on to the fact that these have been outside on the roof the whole time? Doesn't surprise me!

Later this week we'll know!

mrmuse · July 23, 2013, 12:55 PM

My 1976 Coleman was completely dead, not even a hum. Removed the cover, cleaned, checked all connections (clean or replace) WD40 on BOTH sides of blower shaft. Applied power & lo and behold, hum. After a few times hand turning fan, she caught and ran, AND cold too.
Piggy backed a Supco cap to original, some heavier oil, and she starts every time. Total cost was $12.50 and one buddy helping using less than 1/2 hour...37 years old and runs great. (AC not me)......

mrmuse

aaron7 · July 26, 2013, 06:49 AM

Replaced the totally dead cap and... no change. Just a fan; compressor never kicks on.

I'm guessing it lay dead too long and the freon made a hole and found its way out.

Was worth a shot!

Now back to my original question; what's a good brand AC unit to buy?

ClydesdaleKevin · July 26, 2013, 08:01 AM

I've had very good luck with Coleman Mach units. Heck, the original one from 1989 still works in the back of our rig...replaced the front with a new Coleman and it works great, although I'm not crazy about the way the vents are set up. I LOVED the Carrier Air V units, especially the way the vents were so adjustable, you could even close them and lock them shut, and they had a really neat "air shower" feature. They stopped making them, which sucks, but you might be able to find a new one that hasn't been sold yet. Plus they were the lightest ones you could get, at just under 99 lbs. Parts and support are still available from Carrier, they just got out of the RV business. Duotherm is another great brand. Whichever one you buy, check out eBay first...its the cheapest place I've found to get any of them (make sure you calculate the shipping price in the total), and RV dealers will charge you a bloody fortune! Just an example: I needed a new AC for our rig right away and couldn't wait for shipping...we were in the middle of a show in Texas, it was 90+ degrees out and humid, our campsite was in the sun, and I the AC crapped out. We HAVE to have AC for the dogs while we are at work, so we had no choice but to call a mobile RV guy. He proclaimed our original AC dead (the liar...probably just a capacitor), and installed a new Coleman Mach. I almost choked when he handed me the bill for 1200.00!!! I could have gotten the exact same unit on eBay for 500.00 delivered!

Kev