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Topic: New a/c quit (Read 563 times) previous topic - next topic

New a/c quit

Yesterday I noticed that the new rear a/c would quit, then restart immediately. The first time it happened I asked Jo Ann if the front electrics quit, then restarted. She said they didn't. Some time later it happened again. The third time the a/c just stopped working. Hmmm. Breaker okay, thermostat showing that it is on. Oh well, brand new unit, still under warranty so just have to find someone to lay hands on it.

Today I wondered if maybe one of the 110V lines had somehow gotten loose. That might cause such symptoms. I took the covers off and found the 110 line in. Pulled the cover off of that box and poked at the connections. All tight. Yes, the breaker was off. While I was doing that Jo Ann saw a sticker that said something about a thermal breaker. Hmmm.

Buttoned everything up and turned on the breaker. Lots of fan and pretty soon cool air. Working fine now, but I'll keep an eye on it tonight.

Re: New a/c quit

Reply #1 –
When you checked the connections did you hold the wire nuts and pull on the wire for the AC unit to verify it was tight?  The wire nut could be tight but the stranded wire for the AC unit could have missed being caught by the wire nut.  Next check the breaker in the breaker box to verify the wire is tight on the breaker.  Verify that the insulation is not caught by the breaker screw.  Last thing to check is pull the breaker off the buss bar and check the bar and breaker to  make sure they both look in good shape.

There may be a plug where the wire go to the junction box on the AC unit.  Make sure that plug is pressed in all the way.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: New a/c quit

Reply #2 –
Turned out to be a very simple thing. In fact, it was so simple I didn't even think of it. When the air temperature is close to what you want, but it is very humid, an air conditioner will freeze up. Older (dumb) air conditioners kept trying to work, but new ones (smart ones) don't. I probably would have had cooling much earlier if I had thought of that.

Re: New a/c quit

Reply #3 –
Higher fan speed and clean filter help reduce condenser icing.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: New a/c quit

Reply #4 –
Quote from: kb0zke –
Turned out to be a very simple thing. In fact, it was so simple I didn't even think of it. When the air temperature is close to what you want, but it is very humid, an air conditioner will freeze up. Older (dumb) air conditioners kept trying to work, but new ones (smart ones) don't. I probably would have had cooling much earlier if I had thought of that.
And here is a primer on the AC expansion valve: Air Conditioning - Expansion Valve

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)