I have a Carrier Weathermaker 8000 furnace. It has given me a few problems over the years but for the most part has run really well. I have it cleaned, and in emergencies when it is not working I clean the sensor thing.

The problem I have now (it just started last week) is my thermostat has started blinking the time and occasionally goes blank. It is a digital thermostat. I would supply the name of it but I can't find it. I removed the front off the wall to see if it needed batteries or if I could find the make/model number but I couldn't see a battery anywhere nor could I find a make/model number.

Does anyone out there have a nameless digital thermostat that they have had this happen to? If so, is there any way to fix it or is it toast and I need to buy a new one? The furnace isn't working quite as it should and I think this is why. It comes on, but only for short 5 minute intervals and takes a few cycles to reach the heat I set it to.

Thanks in advance.

Post picture of Tstat.

Thanks for getting back to me. I gave up on my thermostat and got a new one. I'd set the time and it would hold it for about an hour or so and then the whole screen would go blank, then it would come back and blink... too frustrating. I installed the new one tonight, cleaned the filter and everything works like a charm so far.