T@b 400 Cool Cat Thermostat Replacement

BigGrover

Has anyone out there replaced their thermostat?  Just wondering how to detach it from the wall.  Ours is apparently not reading the correct temperature.  Went camping in 90+ degree weather this week.  Unit would not stop cooling.  With the Dometic thermostat set at 80 the air temp  reading on the Alde control was showing 72* and the Cool cat just kept on cooling.  Had to keep turning the unit off and on manually.  Contacted Creed at Nucamp and was told to take it to the dealership which is 4 hours away.  I figure it might just be cheaper and easier to purchase a thermostat myself and replace it.

Sharon_is_SAM

Have you calibrated the Alde temperature display against an independent thermometer?  Your Cool Cat/Dometic thermostat could be fine.

BigGrover

Yes, I have set it using the offset function

N7SHG_Ham

Probably be obvious once you get that outside cover off, as with most things, the cover trick is often the hardest Your Alde wasn't heating was it? I do notice that the Dometic and Alde inside temps often vary by a few degrees. (the Dometic display will show inside temp. if you turn it off and then push either up/down arrows) Also the placement can fool both heating and cooling especially if the sun is on the door side (assuming they are by the door in 320, they are in 400). What I usually do is when inside temp is comfortable is adjust the thermostat until the AC kicks off, it then maintains at that temp despite what both the setting is and the inside temp is indicating.

JEB

BigGrover said:

Has anyone out there replaced their thermostat?  Just wondering how to detach it from the wall.  Ours is apparently not reading the correct temperature.  Went camping in 90+ degree weather this week.  Unit would not stop cooling.  With the Dometic thermostat set at 80 the air temp  reading on the Alde control was showing 72* and the Cool cat just kept on cooling.  Had to keep turning the unit off and on manually.  Contacted Creed at Nucamp and was told to take it to the dealership which is 4 hours away.  I figure it might just be cheaper and easier to purchase a thermostat myself and replace it.

@BigGrover
Did you ever find the problem?  I had something similar happen last evening that I can describe only as a runaway AC unit.  After running fine for about three days, the AC started cooling and wouldn’t stop.  Temps inside the camper dropped to around 65 degrees according to a standalone thermometer I keep on the dinette table, at which point the AC just shut down entirely.  No air, no fan.  No popped fuses, either.  The Dometic thermostat was still showing that the unit was on and fan speed was set to low.  I turned it off for about 5-10 minutes and turned it back on again.  It ran fine for about 10 minutes and then shut down again.  I finally just turned it off completely for the night because it was close to sundown and didn’t expect to need it overnight.

I don’t think it was the thermostat itself.  I’m guessing something in the AC froze over causing it to stop responding properly to the thermostat. Usually I’d expect some kind of blockage, but the air filter was reasonably clean and that’s about the extent of my HVAC diagnostic skills. 

Did you ever resolve your problem?  Mine might be related. 

BigGrover

Jeb,
No, I haven't tried to replace it yet.  We are on another trip with it now.  It seems to be functioning normally so far, we are on day 2. If we run into problems again I will just order a new thermostat.  It would be cheaper than traveling four hours each way to the dealer.

JEB

BigGrover said:

Jeb,
No, I haven't tried to replace it yet.  We are on another trip with it now.  It seems to be functioning normally so far, we are on day 2. If we run into problems again I will just order a new thermostat.  It would be cheaper than traveling four hours each way to the dealer.

Good luck.  I don’t think my problem is the thermostat.  But if it resolves yours, I’d like to know that.