Thermostat is too far off.

[paul42]

I have decided that my thermostat is running on the high side.

I have a lab grade digital hygrometer/thermometer. I bought it used and the last time it was calibrated was about 5 years ago, but it seems to be pretty accurate. Outdoors, it matches the readings at the local airport within the specified tolerance - within one degree and one percent humidity. Most of my other temperature and humidity measuring devices match it fairly close.

The one that is the farthest off, is the Robert Shaw thermostat for the Trane. And it is not a consistent error either.

At 72.5 degrees actual, the thermostat says 75. At 68 degrees, the thermostat says 72. So it is running from 2 to 4 degrees on the high side.

The thermostat is on an empty interior wall near the center of the house. No heat producing devices of any kind anywhere near it.

I have no idea what kind of reputation that brand has, but it hasn't left me with any warm fuzzies.

If I have the contractor replace it with the same model, would I have any expectation that a replacement would be any better?

Is there a replacement brand I should ask for instead?

[Shophound]

Since you are planning on adding a whole house dehumidifier to your place, I'd be looking at a Honeywell VisionPro IAQ system...a thermostat with good accuracy AND can control your dehumidifier.

[hvaclover]

White rodgers 1F95 391

[Jay 41]

Since you are planning on adding a whole house dehumidifier to your place, I'd be looking at a Honeywell VisionPro IAQ system...a thermostat with good accuracy AND can control your dehumidifier.

I agree, nice t-stat, you won't be disappointed.

[hvaclover]

White Rodgers 1F95 391 puts vision pro to shame.

[jrbenny]

I have decided that my thermostat is running on the high side.

I have a lab grade digital hygrometer/thermometer. I bought it used and the last time it was calibrated was about 5 years ago, but it seems to be pretty accurate. Outdoors, it matches the readings at the local airport within the specified tolerance - within one degree and one percent humidity. Most of my other temperature and humidity measuring devices match it fairly close.

The one that is the farthest off, is the Robert Shaw thermostat for the Trane. And it is not a consistent error either.

At 72.5 degrees actual, the thermostat says 75. At 68 degrees, the thermostat says 72. So it is running from 2 to 4 degrees on the high side.

The thermostat is on an empty interior wall near the center of the house. No heat producing devices of any kind anywhere near it.

I have no idea what kind of reputation that brand has, but it hasn't left me with any warm fuzzies.

If I have the contractor replace it with the same model, would I have any expectation that a replacement would be any better?

Is there a replacement brand I should ask for instead?

What is the setpoint when it's displaying the listed values?

[paul42]

What is the setpoint when it's displaying the listed values?

That adds another layer of confusion to the mix.

Last night, when it was reading about 2 degrees off, the set point was 74, it was reading 75, calling for cooling, and the actual temperature was 72.5

This morning, when it was reading about 4 degrees high, the set point was 70, it was reading 72, calling for cooling, and the actual temperature was 68.

Right now, the set point is 74, it is reading 71, not calling for cooling, and the actual temperature is 69.

[mark beiser]

Is the hole in the wall behind the thermostat plugged?

[paul42]

Is the hole in the wall behind the thermostat plugged?

I pulled it off the wall and checked - The hole behind it is plugged with the duct sealant I used to seal all the electrical boxes.