Hello, it looks like some people have posted similar issues in the past but head to different results or reasons?

My problem consists basically of:

Set the temperature
Heater kicks
House heats to desired temp
Heater kicks off
House cools
Heater never kicks on again


The easiest way for me to get the heater on again is simply turning off and on the heat switch at the thermostat again, it detects its cold again and sends the signal to heat. This works no problem. It seems as if the thermostat is not detecting that it needs to send the signal again during the cool down. The variance is set at 3 degrees. It just started doing this out of nowhere.

The thermostat is a RiteTemp Digial programmable LCD from HomeDepot about 4 years old. Can the sensor in the thermostat go bad?

I don't want it to be anything with the actual heater itself. :eek:

Thanks in advance!

It sounds like the furnace is locking out. Next time it does this look for a diagnostic light to blink a code.

Ok, where are these diagnostic lights usually located? Right inside the panel of the furnace?

What brand and age furnace?

What brand and age furnace?

Sorry for the long delay, it seemed like it was working again, it's a hit/miss deal.

It is a York and I believe original in the house, so that makes it around 13-15 yrs old.

I did see the LED and its flashing once which indicated by the diagram that it is indeed a Lockout on the Furnace.

Ok, so time to research why a lockout is occurring and potential fix?

Thanks for the help.

All it says is 1 hour lockout? Or does it say something else. Furnaces will lock-out if the pressure switch sticks closed or doesn't close, if it doesn't sense a flame because the gas valve didn't open or weak current through the flame sensor, or the main limit opens 3 times in a row.

All it says is
1 Flash = Lockout - Check Furnace
2 Flashes = Pressure Switch Stuck Closed
3 Flashes = Pressure Switch Stuck Open
4 Flashes = Open Limit
5 Flashes = Rollout Open
6 Flashes = Flame No Call for Heat..


Since its not flashing 2 or 3 or 4 times I can assume it is not the pressure switch or limit issue?