We have an Amana furnace, model guc115c5oc, which does not stay lit. The unit will ignite, and then you hear several clicks ( which seem to be caused by the flame sensor for the rollback feature), and then the flame will turn off. It will try this about three times, and then the flame will shut off - and the unit blows cold air. We have replaced the rollback sensor, the flame sensor, an internal temperature sensor, and the unit has been cleaned. Any ideas? We are wondering about the gas pressure going into the unit, as it is not just a blue flame, but has quite a bit of yellow that shows up.

Checl and set gas pressure using the proper tool to the listing on the furnace label.

Thanks HVAC - we will try this!

I hope that is your problem since it is a simple cure.