Hi,

We have a Carrier gas furnace and a Honeywell electronic thermostat. They are both only a few years old... The furnace has an auto igniter.
Lately, we have had a recurring problem.
We have it set to raise and lower the temperature at different times of the day, it may work great for days and days... Then it suddenly gets freezing, the thermostat looks OK, but the furnace doesn't come back on... If I go down to the furnace and flick it's breaker (looks like a light switch, next to the furnace, not on the actual breaker box), it will turn back on... Then work for a few days... Until it doesn't.

I have read that a dirty filter may cause problems, so I will replace it... Any other ideas?

Please help... My next step is to pay for a service call... Which I don't want to do unless there truly is a need to fix it.

Thank You

A dirty filter can cause the problem that you mentioned. But there are other things that can do the same thing. The furnace has several safety features and if the furnace tries to light and doesn't for several times the furnace sill go into a lock out mode and the only thing that it will do is for the furnace fan to blow until the electric power is interrupted. I dirty or bad flame sensor can cause it. The vent assist fan can cause it if it is not running right.
Your's could very easily be a dirty filter but it could be that you have let the filter go so long that it has gotten the evaporator coil dirty and it may have to be cleaned.

That new of a furnace will have a fault light and a label explaining the faults get us that info for a better guestimate