Inaccurate indoor temperature reading

[azloafer]

We have the Coleman-Mach True Air Central Heating and Air Conditioning unit that comes with all the Winnebago/Itasca Coaches. The room temperature reading is off by at least 5 degrees. When it says that the room is 77 it is really 72 verified by a separate thermometer. We can also feel the difference. I took the cover off of the control unit and it appears to be a circuit board with no adjustment. Am I missing something? Is there an adjustment that I can make? Anyone else have this problem? Maybe I'll have to replace the board? Joe

[Flagelpater]

FWIW Some units have a remotely located temperature sensor. On my unit it is a small white piece of plastic, about the size of a half walnut shell, with slots in it. Make sure the sensor does not have an accumulation of dust or other obstruction to airflow either within the shell or outside. I have seen a relatively small amount of dust make a substantial difference.

[roboniko]

I have the same problem with mine. Different model. Mine is zoned and 1 out of 3 readings are wrong and about 5degrees off. My sensors are mounted on the roof nearvthe intakes. In shop now to fix.

[smlranger]

My RVP indoor thermostat does the same thing. I actually replaced it with a new one a few years ago and it is consistently inaccurate compared to other digital T stats placed nearby.

My theory is that there is heat created by the other electronic gizmos in the One Place panel which affects the reading. Mine is mounted above the panel for the inverter and I am sure some heat rises from the electronics in that panel.

[powerboatr]

Originally Posted by roboniko

I have the same problem with mine. Different model. Mine is zoned and 1 out of 3 readings are wrong and about 5degrees off. My sensors are mounted on the roof nearvthe intakes. In shop now to fix.

i have to agree
my sensors are on the ceiling in the unit.
my TV;s heat flows up tot he ceiling and tricks the a/c into thinking its 77, so by the time it cools off the coach its nearer 70, so we just run the thermostat setting up a degree to compensate

[azloafer]

It sounds like it is something that we can just live with. At least we know that others have the same type of problem so we don't have to waste money on a new circuit board. Thanks, Joe

[Doug Sage]

My display is also several degrees above actual room temperature. I have had the entire thermostat unit replaced for another reason and the reading is still off about the same amount. It is frustrating but we have just learned to adjust.

[AFChap]

You might try pointing a ceiling air duct at OR away from the thermostat, depending on which way you want to adjust the "actual" reading....

[azloafer]

Originally Posted by AFChap

You might try pointing a ceiling air duct at OR away from the thermostat, depending on which way you want to adjust the "actual" reading....

That's a good thought, I didn't think about it and there is an air duct nearby. Thanks, Joe

[vbugles]

Originally Posted by Flagelpater

FWIW Some units have a remotely located temperature sensor. On my unit it is a small white piece of plastic, about the size of a half walnut shell, with slots in it. Make sure the sensor does not have an accumulation of dust or other obstruction to airflow either within the shell or outside. I have seen a relatively small amount of dust make a substantial difference.

Is the sensor (walnut shell) placed in the unit or somewhere in the coach?

VBUGLES

[Flagelpater]

One of my sensors is mounted under the front TV Cabinet the other is in the beadroom under a wall cabinet. They try to mount them about chest high, out of the sun.

[Alan Hills]

I have a 38 T Itasca 2007. My thermostat has been driving me crazy. It will sometimes read 95 degrees when the room temperature is 78. The A/C will come on and stay on for hours once it has reached the set temperature.
I am constantly re setting the set temperature to get the room temperature to a comfortable setting. Basically there is no relationship between what the actual room temperature is and what the thermostat reads.
I finally found a reply that mentioned that the actual sensor for the room temperature is on the back of the thermostat housing. My thermostat is mounted on an outside wall of the coach to a metal control panel. When I removed the housing I found a 2" Diam. hole in the wall that the wires go thru. Now things are getting interesting. The temperature sensor is actually measuring the temperature inside the outside wall.
The cure...... Took some duct tape and sealed off most of the hole in the wall allowing just enough room to carefully feed the wires thru. Next, picked up a couple screws 1/4" longer than the two original ones that I removed. Next put two 1'/4" thick 3/8" nuts over the screws on the backside of the panel creating a spacer that held the thermostat away from the wall. It now works so much better. The temperature still reads slightly higher than the actual temperature but I don't get the wild swings in temperature reading every time the sun comes out and heats up the outside wall. I have set
a comfortable temperature in the coach and it has been coming on and off perfectly and maintaining the set temperature within One degree. Hope this works for other people. Total cost 48 cents.

[Wyatt]

We sell homes, and I have yet to see one with a thermostat mounted anywhere but on an inside wall, for this very reason.