Rear A/C & Heat Pump unit - Onan Coolent Leak

[Old Rv'er]

Hello All,

Tried to find previous posts on these two issues, no luck. Someone told me the rear A/C unit has "dip" switches which can control how they are working, have not gotten up on the roof to see. The A/C part works fine, it just won't go into Heat Pump mode on the rear unit. The front unit works fine. Must be a loose wire, which I will have to find by taking apart the shroud in the Bedroom and check all the connections and up on the roof as well. Funny thing, the thermonstat when showing Zone 2 (rear) on electric heat selection, periodically flashes "gas" in the display like it also trying to start the hydrohot, which is may be trying to do, but I have that unit shut down. It's not life or death this work, as I use them to give the genset a load so I can run it 2 hours a month like I am supposed to. RV is in storage now.

Larger concern is the coolant leak in the Onan Genset. On the passengers side, bottom, where the rubber hose meet a plastic pipe assembly. I will check the owners manual, either the hose is cracked or the plastic part is cracked. Why would someone design in a plastic part, which will fail under vibration or heat/cooling stress, don't we make anything of quality anymore?

Otherwise won't use rig until April. Still working and have a car trip planned for March.

[Old Rv'er]

In searching for information on my problem I found this link for the shroud on the inside of the coach in case anyone needs to replace one.

http://www.rvcomfort.com/rvp/p...ries/chillgrille.php

It should be noted, they carry my thermonstat, but I now don't remember which heat pump units are on top, so I will have to wait until I bring the coach home, level it up, and put out the bedroom slides to get to the manuals.

[Wayne R]

Is the compressor coming on but just blowing cold air? If that is the case I have found that the reversing valve gets stuck. Usually I can run it on AC for a few minutes and then Heat pump, after a few tries it will start heating. The first time I got up on the roof and lightly tapped on the valve. I am not sure that helped. It usually sticks in the cool mode since that is what most of us use the most.

I just changed the antifreeze in my Onan and If you remove the top and passenger side panels you can easily get at the radiator and all connections. We have been “WRVed” on the passenger side panel. The forward lower bolt is trapped by a gusset. I used a Dremel and chisel to get the head off from there working on it is easy.

[Old Rv'er]

Thank you for the information. I cannot get on the roof now because it's in storage. When I bring it home for our pre-trip readying I will fix it then. I figured it's something easy to do. I did run the A/C yesterday, and will do so again the next time I go up to excersize the gen, but I will need to figure out what is causing the leak first. I might have to just take it cummings, since it's still in warranty.

[JimAndLorene]

Most reversing valves fail in the heating mode,but not all, that is the way they are designed. First check as the previous post, to see if the compressor is running. If the compressor is running, shut off all electric to A/C Heatpump unit. Use a ohm meter and see if reversing valve coil showes resistance.If it shows open you might be able to install a new coil. I would think the coil would be 24volts or 12volts,with care you could check to see if it is getting proper voltage.

Alpine
2005 40ft FDQS

[Wayne R]

Slightly off topic. I am sitting down here in Brownsville Texas for a couple of months and have not used the AC or Heat Pumps. Today I started the gen to exercise it. The AC's would not turn on in either mode. I climbed up on the roof and spun the squirrel cages by hand(power off). They were stiff but freed right up. Both fan motors were warm from trying to start.

I climbed down and turned them on and they both worked. Moral of the story exercise these things often. especially when in a salt water environment

[takepride]

Monty:

The dip switches (on mine) are accessible from inside the coach. However, it does sound like a different problem.

I've had the heat pumps not kick on a few times, in the past. Several re-starts seem to have fixed whatever the problem was.

Hmm, I'm going to test mine again tomorrow.

[dgerstel]

Monty,

Have you connected up with the Apex group? From what I can tell, all of the posts trying to help you are from non-Apex owners. Apex's have Coleman ACs and the rest of us have Dometic.

[Wayne R]

Dale,
Thanks for pointing the Apex issue out. I will pay more attention to the model in the future. In fact I was not aware of the switch to Coleman on the Apex.

Was this more to do with interfacing with the Silverleaf or is the Coleman a better unit?

[dgerstel]

Wayne,

To the best of my memory, it was about the Silverleaf interface.

[Old Scout]

Disclaimer--"I am not an Apex owner." Seems from observations that Apexs have either Dometic or Coleman roof units. Assuming the Dometic was still the Duo-therm heat-pump model, this would give you two heat options--if you also had a factory installed Hydro-hot. Does this also apply to the Coleman product, or was it A/C only as the Hydro-hot provides yr heat? Sorry, no help here--I was just curious.....

[takepride]

Oops!

Pardon my blunder (and ignorance). Thanks for your pointer, Dale. Since I've never been in close contact with the hoity-toity version of an Alpine, I've improperly assumed too much.

At the SoCal FMCA show, they had the APEX locked up and under armed guard, so I never was able to compare them. I think it was because they had just sold it to one of our esteemed forum members.

But alas, my ignorance is only outdone by my poverty. I suppose I'll be able to check one out when they start to become secondhand.

[dgerstel]

Wayne, Jim and Takepride,

Your information was relevant to any type of AC/heatpump and was useful knowledge about those issues. My posting about the different ACs used was for Monty and general information. I would not want anyone to stop posting, just because they don't know all of the different models. I don't know anyone who is familiar with all of the model and year changes. Even harder to tell is when any change was made, many (maybe most?) are not by year.

[Old Rv'er]

I guess I was not clear when I initially made this post.

The rear unit won't start at all when heat is selected, no fan nothing. On A/C it works just fine. I am thinking some wire is loose for the unit calling for heat. But I cannot do anything about it till we bring it home to prep for the first trip, that wont' be till April.