Coleman Mach 8 AC unit blowing hot air

[philnail]

We are currently in Bangor, Maine heading south slowly and the front AC is blowing warm. Anyone have any ideas what to check and can they be recharged with Freon?

Does anyone have any recommendations who can check it out up here

[brobox]

First, try recycling the front AC circuit breaker. Push it in, turn it off, then back on. Next would be to pull the cover off of the thermostat, pull the glass fuse and leave it out for at least 10 minutes. If that does not work it will probably be at the AC unit. Hopefully just a start capacitor. Several posts on how to check those.

[philnail]

Originally Posted by brobox

First, try recycling the front AC circuit breaker. Push it in, turn it off, then back on. Next would be to pull the cover off of the thermostat, pull the glass fuse and leave it out for at least 10 minutes. If that does not work it will probably be at the AC unit. Hopefully just a start capacitor. Several posts on how to check those.

I will search for the start capacitor post. I pulled the cover off the ac and noticed the compressor was super hot

[philnail]

I have reset the breaker and pulled the fuse for 10 minutes. Reset the 12 salesman switch and still blowing hot air.

Got on the roof and removed the cover compressor was hot.

I will try to ck the start capacitor and hopefully that is all it is.

Any ideas?

[royals1212]

If you remove the shroud and then have the wife turn on the system you can observe whether the compressor kicks on or not. It sounds like it is trying to start but doesn’t. In this scenario the compressor will get hot and blow warm air. As some stated earlier it could be the start capacitor, run capacitor or associated PTCR switch all located together and all total cost around $35 to replace. If the caps are not disformed or contain bulges chances are they are good. You can look on you tube and it will tell you how to test them with a volt on meter. Another thing to check is the freeze sensor but if that is the case the compressor would not try to come on. The over or under pressure switches are in the closed loop system and cannot be worked on without evacuating the system. In this scenario it is recommended to replace the unit. Hope my ramblings help you solve your issue.

Herb

[brobox]

The easy stuff downstairs has been eliminated, now it's the upstairs fun part. Herb has already gone over the Start and Run capacitors. The are inside of a metal case, easy to get to. While the unit is cool, trace all the coolant lines and see if there is any oily substance, that would be a coolant leak. I stopped there as mine was covered with coolant, under warranty so the unit was replaced with a 400 mile detour. When trouble shooting mine I found a board test with a volt meter, that would tell what may have failed, but I don't know where on Google I found that. It might have been on Airxcel's site.
Now that everything is cool, what does the unit do looking at it with the cover off and someone turns the thermostat on downstairs? Does the compressor try to come on? Fans turning? I don't like to say this, but from what others have posted, your compressor is getting to the age where others have posted theirs came to the end of their life cycle on the newer Mach 8's I hope it is just a capacitor. If it is a capacitor they are about 1/3 the price at an A/C supply house than an RV dealer. Finding one in cool Maine could be a problem, not a lot of AC shops up there.

[Mwoodofd]

What I am going through, and replacing my rear AC. Compressor is trying to lock up. Had a tech check it, and the Amps would drop about half after about 30 seconds, and since they are a sealed system, difficult to and probably more expensive to fix.

Probably worth $150 or so to have a tech test it to see if it is something that can be fixed.

Mine needs replaced. Mach 8 15,000 BTU with Heat Pump and Condense Pump (Heat Pump is 6000 BTU) - about $1030 on line with free freight. I am going to replace myself.

[brobox]

I found the trouble shooting guide I used that had a nice step by step in section V
https://www.airxcel.com/DesktopModul...df/1976665.pdf

[philnail]

Thanks everyone for all the help as it is much appreciated

I got on the roof and had my wife hit the unit on. The compressor started and fan started fine.

Anyone have any more ideas

[brobox]

Originally Posted by philnail

Thanks everyone for all the help as it is much appreciated

I got on the roof and had my wife hit the unit on. The compressor started and fan started fine.

Anyone have any more ideas

Last block of info in section V:
Air Flow Restrictions, High Ambient Temperature, (Undersized) Too Much Heat Gain To The Vehicle, Refrigeration System, Very Little Or No RefrigerantCharge, Compressor (IF YOU HAVE NOT BEEN PROPERLY TRAINED IN REFRIGERATION SEALED SYSTEM REPAIRS, DO NOT ATTEMPT TO BREAK INTO THE SYSTEM.)


The first items are not issues, looks like the compressor might be giving up the ghost according to the manual and the experience Mark just had.

[Harleydeal]

Had a similar problem yesterday. Kitchen unit. The compressor would come on for a minute and then shut down. Vegatouch would only show fan running. For shits and giggles I turned it off on the Vegatouch and turned on the manual override and it works perfectly. Calling Firefly today. It seems we sometimes chase hardware problems that turn out to be software issues.

[brobox]

Originally Posted by Harleydeal

Had a similar problem yesterday. Kitchen unit. The compressor would come on for a minute and then shut down. Vegatouch would only show fan running. For shits and giggles I turned it off on the Vegatouch and turned on the manual override and it works perfectly. Calling Firefly today. It seems we sometimes chase hardware problems that turn out to be software issues.

Happened to my VT as well, but Phil has the nice simple Classic. Took 3 reboots of the VT to get mine working, Phil isn't that lucky.

[voltdoc]

Hey Phil, have you tried operating the unit in heat mode? If it generates heat I think that would indicate your compressor is OK and perhaps there's an issue with the reversing valve system?

[royals1212]

On my unit, it would start up and cool for about 30 minutes. Then after it cycled off and then when it was time to restart the compressor would try to start and not fully start. The compressor would start getting really warm at this point. I changed the capacitors and it did not help. Mine could be a motor starting to fail, high pressure etc. Unfortunately these issues all require the unit to be changed. NIRV is taking a look at it on Monday, most likely changing the unit out under extended warranty