New High Efficiency Furnace Problem
Excuse my choice of words but my knowledge of furnances is limited at best.
In the Spring we purchased a new American Standard 90+ high efficiency, single stage, furnace.
Periodically, usually once a day, the furnance will attempt to come on then will make a banging noise and then shut off. It will then attempt to re-start. Sometimes this will repeat up to 4 times before the fan comes on and the furnace is operational. We noticed that it also vents a small amount of natural gas outside when it shuts down (pvc pipe).
Most times the furnace starts up without any problems.
The furnance is still under warranty so I had the installer back out to look at it. On the phone he thought it was the flame sensor but he said that in order for it to be the flame sensor this problem would need to be consistently occuring.
His assessment was that there was nothing wrong with the furnance. Unfortuneately the problem did not occur when he was testing it.
Any ideas what might be causing this.