strange Dometic thermostat problem.

[peaeye1]

This a strange one, at least to me, perhaps someone on here can give some insight. I will be as concise as possible.

1. Dometic ccc2 thermostat model 3314080.000

2. Inside temp has never been right since we got 5th wheel, sometimes read right,and after running unit for a few minutes would drop to 45 degrees.It is now a matter of sensor wire being exposed to cold air, in fact I could fool the sensor with a heating pad, and keep bedroom ac going.

3. Got new sensor wire, pluged into upper unit, same result as above.

4. I just unplugged the sensor wire connection, and cranked up the bedroom ac, worked fine, ran it 5 or 6 min, no shutdown, the odd part is still showed inside temp reading for bedroom 87 with wire disconnected.

5. Just have 30 amp in shed, so shut dowm bedroom , cranked up living ac ran fine, inside temps read right.

I guess my question is, do I have bad wiring, bad control board, any suggestions.

[peaeye1]

dougrainer wrote:
Where is the sensor TIP on Zone 2 located? If you plugged into the plenum and the wire is 15 foot long, where do you have the sensor hanging at? 15 minutes is NOT going to do squat for a test. What you need is a digital Thermometer NEXT to the remote Zone 2 Thermister bulb. Lay it ON the bed on a piece of cardboard next to each other and watch what each says for temp measurement. Doug

Had the remote sensor,zone 2 bedroom, laying on the bed covered with a thick cloth. I probably do not own a digital thermometer like you describe, i have a digital meat thermometer.:)

[dougrainer]

Where is the sensor TIP on Zone 2 located? If you plugged into the plenum and the wire is 15 foot long, where do you have the sensor hanging at? 15 minutes is NOT going to do squat for a test. What you need is a digital Thermometer NEXT to the remote Zone 2 Thermister bulb. Lay it ON the bed on a piece of cardboard next to each other and watch what each says for temp measurement. Doug

[peaeye1]

dougrainer wrote:
Which ZONE is the Bedroom? Zone 2?
When you replace the sensor, WHERE is it going? Is it hanging from the roof Plenum area? Are you cutting and splicing? Where is the original sensor located?
When you remove the Zone 2 sensor, the temp reading defaults to the Zone 1 sensor. The Zone 1 can either be a remote sensor like you have for the bedroom or it can be the CCC2 Tstat. Which is it? You have a Zone 1 remote sensor also?
If the bedroom sensor is anyway in contac with any duct blowing cold air on it, it will not react correctly. Doug

Replaced the sensor, the connection was in the plenum , not cuttindg and splicing,original sensor in bedroom, sensor in question is for sone 2 which is bedroom,I do not have a remote sensor for zone 1, the zone 2 sensor is not in contact with cold blowing air.

The connection for sensor wire is zone 2, when I did the initial troubleshooting, I just found the connection in the plenum and plugged the new sensor to it, I did not try and route the wire thru the ceiling and wall until I determined if that was the problem. I covered the sensor tip with a cloth to keep any cold air from interfering with its operation.The results were the same

Just now went out to trailer and cked the inside temps on both sones, both read 72, which is about right, I ran zone 2 ac 15 min with bedroom door shut with no change in inside reading for zone 2. I know it was much colder than 72.

Then ran zone 1 ac with a starting inside readind of 72 and set the temp to go down to 71, when it reached that temp it turned of as it should have.

[dougrainer]

Which ZONE is the Bedroom? Zone 2?
When you replace the sensor, WHERE is it going? Is it hanging from the roof Plenum area? Are you cutting and splicing? Where is the original sensor located?
When you remove the Zone 2 sensor, the temp reading defaults to the Zone 1 sensor. The Zone 1 can either be a remote sensor like you have for the bedroom or it can be the CCC2 Tstat. Which is it? You have a Zone 1 remote sensor also?
If the bedroom sensor is anyway in contac with any duct blowing cold air on it, it will not react correctly. Doug