[Darrell85]

I just completed a residential pm on a Trane 2 stage gas furnace. After I went through everything, I turned the power back on to the furnace, went to the thermostat and the screen is blank and flashing. This is a touch screen thermostat model # TCONT624AS42DAA. Anyone else experience this issue in the past?

 

[BNME8EZ]

Did it ever come back on? I have never dealt with a 624 but have a lot of 824's out there. That is the one thing I hate about them is that they have to reboot and go through what appears as the installation of the operating system.

 

[Darrell85]

It was actually at my secretaries house, so after messing with it for a few minutes, I told her that I would take care of a couple no heat calls and stop by after. It never came back on while I was there though.

 

[BNME8EZ]

It seems like it takes several minutes for them to do their thing. But usually the 824's anyway have a circle of dots that spin and says initializing. The 624 is cheaper version so it may be blank. Like I said I have never worked on one.

The other thing to check is make sure you didn't lose a wire going to the stat in the process of servicing.

 

[Darrell85]

I actually checked to make sure that I still had common and 24v at the thermostat wall plate. It still hasn't came back on. I'm going to chalk it up to just a typical Monday.

 

[VTP99]

Is it getting it's power from the furnace ?

 

[Darrell85]

☝

 

[BNME8EZ]

Did you try cycling the power.

I changed a filter that had to go in through the blower door. Put the door back on saw the lights on the board come on and left. I got a call the next day the lady didn't have any heat the display was blank, HW 8411 stat I think. Went out, looked at the stat, blank, went down to the unit looked at the lights they were running normal. Took the door off, checked the fuse, put the door back on, the lights came on, went upstairs the stat was lit and started working normally.

 

[szw21]

Agree with trying to cycle power. If the electronics inside the thermostat is not well designed a spike in the supply as it comes up can cause the electronics to latchup. Ideally the internal power supply rails should have protection against something like that occurring.

 

[actech2]

Hate how indoor temp display is off after a power down until those stats warm up.