Just recently my Amana GUCA/GCCA will turn the heat on for 4 minutes or so, turn off, flash 4 times (clean filter, blocker return grill) and then will restart. I did replace the filter but did not resolve the situation. I am guessing maybe Primary or Auxiliary Limit looking at the book. I had replaced the controller board last year and have check both pressure switches and they seemed fine. The flame looks good up to the time it quits. Not sure what to do for sure before I call somebody. Any help would be great since the house in getting cold!!

4 is high limit switch, could be getting week, or you could have too much gas pressure. Doe you have any damper? Or closed registars?

I do not have any closed registars and do not have any dampers. I did play with it a little bit tonight. At around 2 minutes and 30 seconds, the flame would go out. I measure the primary limit switch and it did seem to open up with my meter. I unplugged the 2 wires and shorten them together and the funance came back up and ran past the previous shut time until the room temperature was met. I am guessing that means it is the primary switch might have gotten weak. Would that be the high limit switch you are referring to? My air flow seems to be good. It is possible to have a different problem? Do you possibly have the part number I need to purchase? Any other things I should check next? Thanks for all of your advice so far!

Chuck

Well if it is the high limit switch. Like I said sometimes the switch will just get weak. But you may have a more serious problem. If your filter is clean and you are getting good airflow. You may have to high of gas pressure. ( have you seen the gas company working anywhere near your house?) The may have messed with the gas pressure in your area. Or you could have a cracked heat exchanger causing the limit to trip. You may want to have it checked out. A good way to tell if it may be the heat exchanger is watch to see if the flames change any when the fan comes on, or go outside and sell the vent of the plastic pipe. If you have a real foul egg type smell it may be bad news. How old is the furnace?

I have not seen any gas work in my area to my knowledge. The flame seems pretty constant when looking at it. IT does have the nice blue burning flame. I haven't smelled the raw natural gas smell at all but I will need to get outside tomorrow and check it out. Would I also smell the gas in my house coming out of the registars? My gas fireplaces and water heaters have been doing fine. We had not been using the heat at all until recently and this problem creaped up so it seems like a new problem for cranking up the heat for another year. The Amana system is probably 8 years old. I don't believe the switch is that expensive. Would it be a bad idea to purchase one to see if that is the problem before I have anyone come check for a cracked exchanger?

Thanks again,
Chuck

I would say if you do not see a change in the flame. And the vent does not smell bad. Then change the limit switch. Probably about $28 take the old one with you. It will have the temp range on it. You should be able to pick one up at any hvac store

I cleaned my flame sensor with sand paper and my Amana AMV9 seems to be working fine. It was cycling on and off with NO blinking codes resulting. I plan to also purchase a new sensor to replace this one. Hope that helps...