basement ac loud compressors

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KenA

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Joined
Jul 15, 2006
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9
I have a 2006 Winnebago with the Coleman basement ac. All functions properly, voltage, etc. (heat and cooling are not up to snuff). The compressors start correctly but when they do there is a very loud almost harmonic vibration that fades in and out. I have replaced the fan motors and bearings hoping it was the problem, no such luck. I am ready to buy a new unit from Dyers, I would just like to know if a new unit is quiter.
 
    When you were working on the fans did you check the isolators under the compressors? I have seen some on larger units that have shipping restraints on the mounts.

    If you decide to take another look, check to see if all the piping is not touching something that will transmitt the sound. Just some thoughts..good luck
 
KenA said:
..All functions properly, voltage, etc. (heat and cooling are not up to snuff). ,,
I'm confused. You say "all functions properly" and then "..are not up to snuff." Which is it? Before you replace the entire unit I would replace the start and run capacitors and see if that helps.
 
I don't notice my new unit installed last summer sounding any different from the original. Some owners are bothered by the drone of the compressors while others are not.
 
By all functioning properly I mean everything cycles and operates correctly as per my readings in this forum. The heat is warm at best and the ac is cool not cold. The compressors sound as if they are struggling to stay on
. It is a 2006 unit, could the compressors just be worn out?
 
Okay, so you have no heatpump and no cold air.  Run the generator and turn the set temperature way down in cool mode. After the blower, compressor #1 and compressor #2 cycles on you should be reading about 21-23 amps at the OnePlace power management panel. (Turn off the water heater.)
 
If you see the normal amp usage range as described above, in my experience there are two other reasons for poor cooling. 1 - low refrigerant, which is highly unlikely (it is a sealed system) unless a compressor has previously been replaced which requires addition of a charging port; or, 2- the air duct coming out of the unit and going upward behind the rear cap is separated in one or more places.  Duct leaks are very common. I have re-taped the joint at the bottom where the duct turns upward probably 3 times over the years, totally removing and re-doing it with metal tape last summer. As far as I know, I have not had a separation about half way up the cap as several others have had.  You can check for duct separation by running the unit and lying on the ground feeing for cold air behind the cap, AND by running the unit on a warm day and checking for cool spots on the outside surface of the cap.
 
Yeehah !!! A new Coleman Mach unit from Dyersonline was the only solution. I performed every test that was suggested in the forums, the compressors where loud and had a "hammering harmonic sound" . I believe they were just "NFG" This 2006 Winnebago Adventurer 35A has very low mileage (14,500) but the neglect and rust and corrosion are unbelievable, not to mention the rodent eaten wiring. I am slowly trying to restore it as best I can. My next target is the left side slide out. Does anyone have any experience with adjusing them? I should start another post.

Thanks to all for your help and knowledge, it made the job much easier.

New unit is so quiet compared to the old one, and it is actually cold in no time, money well spent over all.
 
Yeah, start a new thread about slides. I'm a a DIY guy but I won't mess with slides, they are black magic.  ;) Congratulations on the new basement air!
 
KenA said:
Yeehah !!! A new Coleman Mach unit from Dyersonline was the only solution. I performed every test that was suggested in the forums, the compressors where loud and had a "hammering harmonic sound" . I believe they were just "NFG" This 2006 Winnebago Adventurer 35A has very low mileage (14,500) but the neglect and rust and corrosion are unbelievable, not to mention the rodent eaten wiring. I am slowly trying to restore it as best I can. My next target is the left side slide out. Does anyone have any experience with adjusing them? I should start another post.

Thanks to all for your help and knowledge, it made the job much easier.

New unit is so quiet compared to the old one, and it is actually cold in no time, money well spent over all.
FYI ... I kept seeing owners saying we need to install a "hard start" kit, so figured I would check that out. Dyersonline could find no info on such a kit for my unit so I contacted "the horses mouth" at airxcel.com and they told me it basically is already installed ...nothing to add.
 
Everything you describe sounds like the unit is working properly and you're about the spend $4k (or whatever) to prove that out.

The heat pump on ours is warm, never hot, and it takes awhile to get there. Likewise, with the AC, it will never be as cold as sticking your hand in front of a rooftop unit. Ours can keep the coach in the 70's at 100 degrees external, but again, it takes awhile to get there with heat soaked walls; I doubt rooftops will fare much better. You need to do a little more detailed testing with a thermometer stuck in the vent and see what the delta is between inside and outside air, also you need to be looking at the rear ducting for leaks, something a new unit won't fix at all.

As far as the compressor "drone", yes, they do that and your new one will too. It's not the fan, it's the compressors rotor speed beating against each other.  If you REALLY can't stand it, consider installing a rooftop in the rear for sleeping, or replace the coach.
 
I had my basement AC repaired before our trip out west and it has performed very well to date....big test coming up next weekend as we will be a day in Redding CA (112 degrees) and then to Greenfield CA (101 degrees) for 2 days....
 
SCVJeff,
"New unit is so quiet compared to the old one, and it is actually cold in no time, money well spent over all."($2,300)

Also a side note, When I wired the new unit thermostat I just copied how the "Gem of a RV dealer in western Ma." had wired the thermostat. Luckily I had a refrigeration control tech take a look at it . They had forced the #2 compressor to run all the time because the #1 compressor was no good.
 
KenA said:
SCVJeff,
"New unit is so quiet compared to the old one, and it is actually cold in no time, money well spent over all."($2,300)

Also a side note, When I wired the new unit thermostat I just copied how the "Gem of a RV dealer in western Ma." had wired the thermostat. Luckily I had a refrigeration control tech take a look at it . They had forced the #2 compressor to run all the time because the #1 compressor was no good.
Sounds like your basement unit was not running correctly when you made the purchase because someone cobbled it up. Normally, if #1 compressor is not running #2 will not turn on.
 

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