Roof top AC

Update on MY A/C... One of my rooftop units has been tripping its 20 amp branch breaker... I put a meter on the wire and confirmed,, IT IS THE A/C not the breaker.. So this AM I got the ladder down, went topside with ye old screwdriver and ye old air shooter, pulled the covers and blasted the unk to .. somewhere else... About 2/3 of the condenser was covered with fibrous stuff that builds up on those things.. It's all clear now.

Came back down and turned it back on and ... no click of darkness on that line all day, still working as I type 11 hours later.

These things are very easy to replace. The hardest part is wrestling them around. Over the years I have replaced a few of them. The last time I bought a 13,500 from the scratch -n- dent section at PPL motorhomes. It's a Dometic and works like a champ. The frame on it has a good ding to it like the box was dropped. But, I saved a hunk of change so, who cares. Anyway, the physical size and weight of a 13,500 and a 15,000 is the same. I think they weigh about 80 pounds or so. Everyone I have done I did by myself but, the older I get the harder it gets. The last one was a challenge to get it up there without damaging anything. The wiring is super simple. The new seals are easy to set etc.. Just be sure to have a good surface to mount it too. That's all there is too it.

Vt Rv wrote:
My rooftop Coleman AC blows cool but not cold air. I'm told its a closed system that can't be recharged.

Headed out west this summer and will need AC.

RV repair is suggesting I replace my current unit with a Dometic Brisk Air 1500 BTU AC.

The unit sells for $857. Is this a good idea or are there other options?

You didn't mention if this unit is on your Harley, trailer or class A.... no matter what, your RV's are over 10 yrs. old. I think I would spring for the new one at the best price that you can find. I wouldn't want to try and repair an old unit.

Safe travels,
MM.

Altern wrote:

crasster wrote:
You can add a port if you are comfortable using solder and a torch, but I prefer mapp gas and brazing it with a copper rod. Once you have a port, you can get a vacuum tool to create vac pressure in the line and recharge it yourself. (works for autos too).

IMHO there are so many things about this post that contains poor or mis-information one hardly knows where to start.

You dont solder ref. lines you can clean it that helps get up there with a garden hose and take the cover off and wash out the coil. IF you Need to add some R-22 You can have about any HVAC person do it. We did ours last year. You dont have to go to an RV dealer anyone can do it.

Vt Rv wrote:
It is a ducted unit. I've cleaned the inside filter but haven't gotten up and removed shroud. What would I be cleaning? Is it a matter of blowing out the fins?

You should remove the outer cover (Shroud) then there are two inner covers, one covers the condenser and one the evap..

Before you go "Topside" remove the indoor intake filters and examine the evaporator coils if you can from below using a small flashlight to illuminate the coils.. IF they are clean, then up on the roof you can leave that cover alone.. IF NOT, you will have to figure out how to pull it, instrucitons vary.

Now remove the needed screws etc to remove the CONDENSER cover (The otside coils) and look into the area where the fan lives to get a good view of the real problem.

YOu may need to remove the fan,, THIS may involve removeing the other cover.. Or you may be able to loosen the lock bolt or clamp and move it up or down, or remove it, Or you may not need to remove it, all depends on many things.

Using a brush, clean as much as you can off those coils.

NOW hose them out.

Restore fan if needed

Clean everything else that can stand it that is up there.

I have never seen lubrication ports.. but if you got 'em, use 'em.

IF NEEDED.... Comb out the fins on the coils (Hopefully not needed)

And finally restore all covers.

Should work better now.

How are they going to interface the RVP controls to the Dometic???? Kind of hard to do. Stick with the RVP replacement. Doug

crasster wrote:
You can add a port if you are comfortable using solder and a torch, but I prefer mapp gas and brazing it with a copper rod. Once you have a port, you can get a vacuum tool to create vac pressure in the line and recharge it yourself. (works for autos too).

IMHO there are so many things about this post that contains poor or mis-information one hardly knows where to start.

Here is how I fixed mine.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26175172.cfm

Up top you would cleanthe coil.

Just did my home units last week with foam ac cleaner from home depot.

You can add a port if you are comfortable using solder and a torch, but I prefer mapp gas and brazing it with a copper rod. Once you have a port, you can get a vacuum tool to create vac pressure in the line and recharge it yourself. (works for autos too).