Front AC in RW390 Short Cycling

[Heathcote4]

The AC in the front of our camper (master bedroom) is kicking back on after only about 30 seconds of shutting of. Any idea if this is normal?

Josh


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[Subdrv]

The AC in the front of our camper (master bedroom) is kicking back on after only about 30 seconds of shutting of. Any idea if this is normal?

Josh


Sent from my iPhone using Tapatalk

Josh

I had the problem with my cyclone, if you remove the filter there is a metal and foam piece that separates the supply and return side. When we close the bottom to force the air to the ducts the piece is pushed loose and lets cold air go back in the return side. I used gorilla tape to seal around the edge and problem stopped

 

[Rickhansen]

Josh,
Unfortunately it's not unusual. It is, however, very hard on the A/C. You really want the unit to run for several minutes and be off for several minutes, at a minimum.

It is caused by the discharge air from the A/C blowing on the thermostat tricking it into thinking that the room has cooled down. It shuts off and immediately "feels" that the room is too warm and re-starts. The first thing to do is re-direct the vents away from the thermostat as much as you can.

As you know, there is a ton of air blowing around in a pretty small room. The problem will improve slightly when the temperatures outside and sun heat loads go up.

Depending on if your thermostat has this setting, you should make sure the differential is set to a higher number. This is the difference between the temperature where the A/C comes on (Setpoint) and shuts off (setpoint - Differential). Some thermostats also incorporate a re-cycle timer, like a minimum off time, but this is pretty rare.

I have replaced mine with Hunter Digital thermostats and run the bedroom with at least a 2 degree differential, but still have to be mindful of vent opening and direction. It also helps when I keep the bathroom pass through door open to the bedroom.

 

[drsasser]

Josh,
Unfortunately it's not unusual. It is, however, very hard on the A/C. You really want the unit to run for several minutes and be off for several minutes, at a minimum.

It is caused by the discharge air from the A/C blowing on the thermostat tricking it into thinking that the room has cooled down. It shuts off and immediately "feels" that the room is too warm and re-starts. The first thing to do is re-direct the vents away from the thermostat as much as you can.

As you know, there is a ton of air blowing around in a pretty small room. The problem will improve slightly when the temperatures outside and sun heat loads go up.

Depending on if your thermostat has this setting, you should make sure the differential is set to a higher number. This is the difference between the temperature where the A/C comes on (Setpoint) and shuts off (setpoint - Differential). Some thermostats also incorporate a re-cycle timer, like a minimum off time, but this is pretty rare.

I have replaced mine with Hunter Digital thermostats and run the bedroom with at least a 2 degree differential, but still have to be mindful of vent opening and direction. It also helps when I keep the bathroom pass through door open to the bedroom.

I have a dometic digital thermostat and I'm thinking about changing it, Will the hunter digital work on my A/C??
Also does someone make a thermostat that has adjustable thresholds o I could change the kick on kick off temperatures ??

Thanks

 

[Rickhansen]

You can change to the battery operated Hunter Stat, but it does require you replace the Dometic "Digital" relay box to an "Analog" relay box. You can probably find it on E-Bay fairly cheap. You'll also have to replace the pre-made flat cable to the Thermostat with suitable wire, like 6C #18. A search of the Forums will find you several excellent posts with the details.

The Hunters are good because you can set the differential setting as low as +/-1 degree. I think +/-3 degrees is max.