What a time for the Basement A/C to go out!

[Duner]

I'm hoping that some of the A/C techs can help diagnose the problem before I get to the shop this week.

Ater 4.5 years of flawless operation, our basement a/c decided it didn't like running off the generator with the heat at the FMCA Eastern Area Rally at Richmond Raceway. The very first hour we got there it started going out. Parked on blacktop, near record temps around 100 & with that humidity, what a killer! A strong breeze was blowing the generator heat in the direction of the basement unit and parked on blacktop it was cook'n out there. It didn't make any sense to move to electric area & pay $145 if the a/c was going to quit any minute.

It started out as a not too loud scraping/rubbing type of sound. After two hours we came back it had become quite loud squealing/screeching sound. To me it sounded like a bearing going out in the #1 compressor. With the fan blower only running all was quite. We shut it down, called the local roving RV techs to come take a look, asked the neighbors to keep our dog in their coach, and we ran off to the nice-n-cool exhibit hall.

When the RV tech showed up a few hours later he got under the unit with a flashlight. It was off for a few hours. I turned it on & it was making the scraping/rubbing sound. He didn't think it was a bearing, maybe the squirrel cage touching. He said to continue using it until we could have it serviced in the shop. So we used it all day Thur, Fri, Sat with a continuous loud squealing/screeching and temps around 100 deg everyday. But at least it was cooling off inside like there was no problem.

On Sunday we get to the rv park, it's cooler here @ only 91 deg. Plug in the 30 amp service and the A/C fires up and runs for 5 hrs as if nothing ever was wrong. Today when we turned on for the first time it got the scraping/rubbing for an hour. So I shut it down to cool off for an hour. Now when it came on, got scraping/rubbing for about 90 seconds until it paused while the 2nd compressor fires up, then nice and quite. Now it's been quite for at least 2 hours.

I'd like to get a good idea of the probable cause since my extended warranty does not pay for diagnostic time, but will pay for parts & labor for repairs.

Thanks in advance for your advise.

[FrontRangeRVer]

Is your squirel cage rubbing?

[Duner]

Originally posted by FrontRangeRVer:
Is your squirel cage rubbing?

No I don't think so. From the ground looking up, you can see the squirel cage and it does have a little wobble, but I'm pretty sure it's not rubbing.

[AFChap]

I would place big money on the cause being a bad blower motor. Both of my blower motors have been replaced in two different years. BOTH TIMES the first place I took it to mis-diagnosed the problem, so failed to repair it.

The first time the noise wasn't quite as severe, more an extended chirp on start & shut down. A Winnie dealer said the blower bearings just needed to be lubed. Their cure cost me $300 labor and lasted 3 mo, at which point an independent RVP certified service shop charged me $300 labor again to pull the unit and replace a blower motor.

The second time the noise was more like you describe. Another dealer said the blower motor runout and/or squirrel cage runout needed adjusted. They pulled the unit out (with a LOT of MY help!!) and tinkered with it, $300+ labor. Two months later the noise returned and got worse & worse pretty much exactly as you describe. A second dealership pulled the unit and replaced the other blower motor. Problem cured.

I ABSOLUTELY WOULD NOT ACCEPT a diagnosis of "it just needs adjusted & lubed." All that will do is cost you another labor charge to resolve the real problem a few months down the road. Labor is always $300 plus, blower motor is $150 or so, maybe plus shipping.

If you go to the RVP website, you can get a list of certified service techs wherever you are. Those are the only people who I let work on mine now. RVP is at http://www.rvcomfort.com/rvp/product.../HP_2tonHE.php

[John_Canfield]

Oh my goodness Bill !!

We are in the desert in Gila Bend, Arizona and it is supposed to be 105 today (don't worry, it's a dry heat )

Our coach is nice and comfy and actually should stay that way.

Paul certainly has the right idea about going to an RVP-certified tech. Best luck in getting it repaired. Be sure and let us know how the story ends.

[Mike in Florida]

I had a similar sounding "intermitent" issue, and it was the squirrel cage. The certified HVAC guy looked at it, and supposedly fixed it with a new blower motor.

I finally got tired of the squeal, and pulled the basement air myself. I removed the squirrel cage, plugged it in to 120v, and found a slight wobble, but enough to emit a high pitched squeal at speed. Took the squirrel cage back to the certified tech who said hmmm. He bought me a new cage, and it solved the problem completely.

In my case, the aluminum fins were flexing ever so slightly which was causing the scraping and squealing sound.

[CaptChet]

Hey Duner, I booted up nthis morning, Wednesday, fully expecting a post from you about yesterdays in and out of your A/C.
I don't know if you noticed or not, when I came by you my main slide had come lose or not locked itself or something that caused it to creep out. That is for another post.

Sure hope you nailed your problem.

Good Luck....
and nice to meet you. Look forward to seeing you again, out on the Trail.

[Duner]

Well, as Captain Chet mentioned, I decided to get up early while it was still slightly cool and pull the unit out to diagnose the problem. I figured that if I could confirm the bad components, would try to get the RV service to order the parts and have them ready to install when I arrive. Leaving the rig for 4-7 days at a repair center w/o a/c is not a good situation when fulltiming.

AFChap, you were right on! The outdoor blower bearings were bad – both the external pillow mount brass bushing and the motor bearings too. I swapped the identical indoor blower bearing to try on the outdoor bearing. It was quieter, but still rattled. With the external bearing removed, you could feel too much play on the motor shaft.

Mike in Florida, you were right too. The squirrel cage does have a wobble. Tried to tighten the ¼ in set screw and it was already very tight. Closer inspection and there it was .... a 2 ½ in crack in the hub of the squirrel cage. To help extend the life, I put 2-part paste epoxy over the crack.

I ran around yesterday trying to locate the ½ pillow mount brass bearing at the local auto parts, rv repair, and heating & ac out here in the rural East Virginia. No luck. The best I could find was 5/8 in bore bearing – darn, close but no cigar. I decided to swap the indoor & outdoor bearings to at least get me by thru the week.

Today it was about 12-14 deg cooler and the a/c unit performed well, noisy but not too loud. I located Winnie dealer on my route north & they will order the parts after the Extended Warranty folks approve the repair estimate cost. That should happen tomorrow. I also ordered 2 brass bearings from Graingers to be air freighted here at the campground tomorrow. One is to replace the bearing on the indoor blower which will be ruined running on that bad outdoor motor. The other one is a spare - at $10.32 good insurance.

Having messed with the duct work that goes up the back to the roof, I can see why RV service centers refuse to touch the basement units. As soon as you move that stuff, it starts to fall apart. I spent at least 1 ½ hours taping the duct up again so it wouldn't leak. If you got 4ft long arms it would be easier – mine aren't. The aluminum tape adhesive dries out and a good deal of it is loose. I have a partial roll of Venture Tape left from a new furnace project I did. That stuff works great – expensive but designed not to loose its grip up in hot attics. Soon I will be buying some foil insulation and adding it around the lower duct work. The factory insulation allows a good deal of cold to leak thru. In So Cal, I never felt any moisture there and thought the insulation was adequate. In this humidity, it was dripping wet so a lot of btu's are wasted.

Meet a couple at the campground clubhouse yesterday. They had their dog with them in a carrier – that doesn't look good! They have an Adventurer and they have been without a/c for a week waiting on parts. Another guy came by today & his front a/c roof unit went out. Tries to start but won't run. I suggested he swap motor capacitors with the rear – he could repair himself for about $10 or $20 for a capacitor. At the FMCA rally the rv techs were replacing a lot of starting capacitors on the roof mounted Dometics.

I guess all this is the results you see when a sudden, 1st of the year heat wave hits. All those marginal worn out a/c parts decide to take a dump at the same time. As "AF Chap"� pointed out, I can see how my problem could have easily been only partially or temporarily fixed. If they didn't see, or look for, the crack in the squirrel cage, that would of fell apart in the August heat wave.

With the help of you guys & some luck, I hope to have all this behind me next week.

[Duner]

I've posted the link to the removal/replacement procedure in a new topic here.

There are so many topics on basement A/C problems right now on the forum, I decided a new topic on just how to remove and replace the basement unit was appropriate.