replacing rooftop air conditioner gasket...Does ac need remain upright?

[DavidH]

I've a '95 Class C with a Coleman rooftop ac.  Will soon remove the ac to replace the gasket.   Browsing the web I see some will keep it upright (blocking up on 5gal buckets for example) to clean the old gasket.  And some just turn it on its side.  Curious what folks here do. 

Putting it on its side makes it easier for a one-person job but I noticed one rver saying it's a no no, as the ac may then need be upright for a day to allow fluids to resettle before restarting the ac.  Thank you for any advice.  Rather do it once and do it right.

Edited July 24, 2021 by DavidH

[ARGO]

I have always been told that the oil drains out of the compressor if not upright in refrigerators. If on it's side, just wait 24 hrs after back upright to run it.

[Kirk W]

I think that you might be wise to get advice from an experienced RV tech as few of us have done what you are about to do. I did help a friend do that job on an RV with a Dometic a/c and we set his on some wood cribbing rather than on the side. I have always gone to the more conservative side when in doubt. My recommendation would be to keep it right side up, just to be sure you don't make some new problem. That unit is now 26 years old so why take extra risk of creating a new problem, if you can avoid it?

[Ed ke6bnl]

1 hour ago, ARGO said:

I have always been told that the oil drains out of the compressor if not upright in refrigerators. If on it's side, just wait 24 hrs after back upright to run it.

when I worked on air cond. and refrigerators it was not so much the oil draining BUT that it would some times clog up in a line when set on its side and then would not work. BUT then again I have move hundreds of refrigerators on their side and let stand for a couple of hours or best over night and I have never had the problem they talk about.

[TXiceman]

I always roll the A/C on the side to replace a gasket.  Have not hurt one yet.  When I do get the unit reinstalled, I let it set for an hour to give the oil time to drain back.  On the A/C units, there is always a little oil moving through the system during  operation.

Ken

[Kirk W]

10 minutes ago, TXiceman said:

I always roll the A/C on the side to replace a gasket.  Have not hurt one yet. 

Since I have only ever done 1 and didn't roll it, how many have you done and what brands and age? Just wondering for my own learning?

[oldjohnt]

Ive changed a couple, never had a problem, BUT I KEPT THEM UPRIGHT.......I was afraid to lay them on their side but I cant say how good or bad or if it doesnt matter ?????

 John T

  

[DavidH]

Thank you all, much appreciate the shared experience and wisdom here!

[Kirk W]

Please let us know what you do and how the project works out, if you would.

[DavidH]

I will Kirk, already clear best choice as you and others note is to keep upright.  So clarifies and settles my thoughts reading the helpful comments, and education, as want to understand the Why's behind the choices. 

 

 

[durangodon]

My anecdotal story.  When they replaced my roof, they hung both a/c units on a ceiling beam with a hook.  Both were like that for three days, basically with the front up and rear down.  They re-installed them and I was using both within a couple of hours after install.  They're still working fine years later.

[oldjohnt]

I'm sure you already plan to do this, but a thorough removal of any old sealant or gasket/tape and crud etc then drying is essential. Off topic a bit, but on flat roof RV's the weight of the AC can cause a roof sag and I have been known to use creative methods of raising and bracing the roof just a tad in that area to prevent water accumulation near the AC...Such may appear a bit jury rigged but it works lol

 Let us know how things work out

  John T

 

 

[D&J]

Being yours is a older unit that still has a strong base plate I would just roll it up on its side replace the gasket clean the roof area and set it back down. The newer ones I've replaced the last one being a Coleman had a very weak base plate and would never take being rolled one it's side. The low profile units have the compressor laying down or almost down so a few minutes it would be on it's side will hot hurt it.

Denny

[Ray,IN]

Just thinking out loud; if the oil in a compressor will drain to an unwanted place, how pray tell do those folks replacing their MH refrigerator do so  without laying it down?

Edited July 25, 2021 by Ray,IN

[Pat & Pete]

1 hour ago, Ray,IN said:

Just thinking out loud; if the oil in a compressor will drain to an unwanted place, how pray tell do those folks replacing their MH refrigerator do so  without laying it down?

We laid the old fridge down to dismantle it . The new fridge came in the door hole without much of a tilt and even less when put in it's new home . 

[TXiceman]

On 7/24/2021 at 8:56 AM, Kirk W said:

Since I have only ever done 1 and didn't roll it, how many have you done and what brands and age? Just wondering for my own learning?

Dometic and Coleman and my new Coleman Mach 8 Plus when installing.

Ken

[RV_]

I kept mine upright when I replaced it on my last full-time rig. I had a friend come up and help pick it up level and help me put it down on a piece of plywood to protect it, but as well to not cut the EPDM membrane. Or damage whatever material the roof is made from. It was pretty easy for two guys to pick up and move over to the plywood, which was just a bit larger than the A/C base plate.

It is not just about the oil in the compressor to me. As well, if you mishandle the high pressure line and break it the oil will leak out over the roof, which is what happened to mine. IT dribbled out with the condensate and my roof was damaged, eaten away, such that I had to patch it, about three square feet with an EPDM kit.

[DavidH]

On 7/23/2021 at 8:40 PM, DavidH said:

I've a '95 Class C with a Coleman rooftop ac.  Will soon remove the ac to replace the gasket.   Browsing the web I see some will keep it upright (blocking up on 5gal buckets for example) to clean the old gasket.  And some just turn it on its side.  Curious what folks here do. 

Putting it on its side makes it easier for a one-person job but I noticed one rver saying it's a no no, as the ac may then need be upright for a day to allow fluids to resettle before restarting the ac.  Thank you for any advice.  Rather do it once and do it right.

 

Edited July 27, 2021 by DavidH

[Ray,IN]

On 7/25/2021 at 4:59 PM, Pat & Pete said:

We laid the old fridge down to dismantle it . The new fridge came in the door hole without much of a tilt and even less when put in it's new home . 

So you were able to keep the residential refrigerator upright while getting it into the RV? What I'm saying is, most with residential fridges say operating out of level is not a concern. I take this to mean laying it down should not also be a concern.

A rooftop air conditioner uses the same basic type sealed compressor as a residential fridge.

[DavidH]

I've a mobile tech due in two days, his way is to put it on its side, but thanks to everyone's comments we'll at least do it early in morning so time to let it sit if need be before heat of the day comes on. After two mobile techs did not even return my calls was more motivated to go with the first presumably competent one I could find. Local state park ranger spoke highly of him.

 

New question I did not think to ask before.... while the ac works as well as last year, a difference this summer is after an hour or so running, the airflow rate is sometimes significantly less---sometimes, not always, like an old soul that occasionally runs out of oomph, that is, just barely maintaining temperature at that point, not cooling down anymore. Shut it off for a couple of hours and then it cools with full airflow force again. My guess is the coils may be clogged/quite dirty, appreciate hearing anyone's thoughts. The more understanding I have the more apt I am to appreciate the tech's know-how level and how thorough they are. Thank you.

[Pat & Pete]

4 hours ago, Ray,IN said:

So you were able to keep the residential refrigerator upright while getting it into the RV? What I'm saying is, most with residential fridges say operating out of level is not a concern. I take this to mean laying it down should not also be a concern.

A rooftop air conditioner uses the same basic type sealed compressor as a residential fridge.

We were able to keep the new fridge at , I'm guessing , about a 20ish degree angle while bring it up the stairs , through the door hole and onto the MH floor . Once inside , it was kept fully upright . 

We also left it in it's new home for about an hour before plugging it in , just to be safe . We had other things to do , anyway .

That angle wasn't too far off what the fridge went through when unloading from the pickup used to transport it . I had unpacked the fridge , moved it to a spot under the awning and plugged it in . It was chilled within half an hour and ready for use , while we removed the old Norcold . So I wasn't real concerned about ill effects after moving it into the MH . 

This particular fridge had instructions that included it could be laid on one side ONLY and no other sides without any harm or having to wait any time before use . 

I think it was the left , but I've forgotten for sure which . 

[RV_]

It sounds like you have lost some refrigerant. That causes them to freeze up the inside A frame coils the air goes through. Melt the ice then the full airflow can go through.

[TXiceman]

Freeze ups do not necessarily mean low on Freon.  9 times out of 10 it is a low or restricted air flow for the evaporator.  Check the air filters, check that the evaporator coil is clean and make sure you are not bypassing air in the inlet of the unit.  Also, if freezing is a problem in certain conditions, run the unit on high fan, not low fan.

Ken

[Ray,IN]

16 hours ago, TXiceman said:

Freeze ups do not necessarily mean low on Freon.  9 times out of 10 it is a low or restricted air flow for the evaporator.  Check the air filters, check that the evaporator coil is clean and make sure you are not bypassing air in the inlet of the unit.  Also, if freezing is a problem in certain conditions, run the unit on high fan, not low fan.

Ken

Yup, there's a thread on a different forum concerning lack of cooling. I explained what happens when only the green mesh "filters" are used. He could reach his basement unit's evaporator coil and said it felt like a shag rug. He removed the unit, cleaned and serviced everything, then reported performance was greatly improved.

He included pictures of before and after cleaning, saying most of the "rug"  was cat hair.

[RV_]

Ken I agree.

But the condenser coil can screw up the system too and increase operating temps in the compressor, and/or cause it to fail prematurely.

If anyone has not at least annually done a full cleaning/inspection of your A/C from above and below here is a video that does it exactly as I did and as the professionals do it:

I also cleaned it more often whenever we stayed in extremely dusty conditions when operating it. Just road dust is fine with annual cleaning.