New Dometic A/C unit

[cptngym]

Just finished up changing out my 15 year old A/C unit did the board conversion on the ground to use the original CCC thermostat. Wiring went well, but when it came to lining up the holes and bolting it down....nothing lined up. What a pain. We got it bolted down, and sealed up. But took much more time than I thought it should have. All the old holes are sealed up and gasket is pulled down as per instruction's. To bad the holes could not have matched up. But the bright side is we have a nice new unit and it is quite.

[1dutchstar]

Jim you did well.

[bruceisla]

Originally Posted by cptngym

Just finished up changing out my 15 year old A/C unit did the board conversion on the ground to use the original CCC thermostat. Wiring went well, but when it came to lining up the holes and bolting it down....nothing lined up. What a pain. We got it bolted down, and sealed up. But took much more time than I thought it should have. All the old holes are sealed up and gasket is pulled down as per instruction's. To bad the holes could not have matched up. But the bright side is we have a nice new unit and it is quite.

Way to go !!

BTW, I found the gasket compression routine didn't work well for Newmar top mounting. Torque specs don't really apply since they were calculated for a conventional bottom mount airbox rather than lag bolts. I also found the "compress the gasket by half" to be too much and caused vibration. I wound up with "compress the gasket evenly (a little at a time at each corner) until the rear rubber blocks just touch the roof and remain touching when you slightly lift the unit at each corner". Basically, the big gasket is compressed about 1/4" - 3/8". In other words, don't overtighten or you'll twist the frame. I've replaced 3 units with this technique. This assumes use of genuine Dometic gaskets ... which are denser than generic (Camco) gaskets.

[owr]

Yes I just changed both of mine and went with 15k heat pumps...and all but 1 old bolt were off...so sealed all but one in front and installed them anyway ...everything else went well and they work wonderfully !
I changed the t-Stat as well to the new one works fine and pretty much dropped in !

Great job just more work than expected !

Enjoy !

[cruzbill]

Our MH is in the shop now having the AC replaced. (2005 penguin ii heat pump, 15k). What should I tell the mechanic?

[bruceisla]

Originally Posted by cruzbill

Our MH is in the shop now having the AC replaced. (2005 penguin ii heat pump, 15k). What should I tell the mechanic?

Should be routine on a Beaver .... the top mount bolts are only on a Newmar.

[bruceisla]

Originally Posted by owr

Yes I just changed both of mine and went with 15k heat pumps...and all but 1 old bolt were off...so sealed all but one in front and installed them anyway ...everything else went well and they work wonderfully !
I changed the t-Stat as well to the new one works fine and pretty much dropped in !

Great job just more work than expected !



Enjoy !

Same here ... 3 out of 4 new holes. Luv the new thermostat with the feature to check the temp at each room sensor.

[cptngym]

If he has changed them before he already knows the original holes don't line up. My back one had been changed and who ever did it "made" some studs with a backing plate of some sort. Pushed them up from the bottom, I guess they could access it threw the 14 inch hole. They used that to bolt down the unit.

[bruceisla]

Originally Posted by cptngym

If he has changed them before he already knows the original holes don't line up. My back one had been changed and who ever did it "made" some studs with a backing plate of some sort. Pushed them up from the bottom, I guess they could access it threw the 14 inch hole. They used that to bolt down the unit.

The 14" hole "should" be surrounded by a frame that is attached to the roof crossmembers. The A/C is lagged thru the roof skin and into this frame. It is not normally attached to the roof skin.

[cruzbill]

Bruce, Thanks-ahhhh! (sigh of relief!)