We had a Carrier Performance 93 furnace (Model 58M__) installed with new AC in May of 2008. Furnace worked fine last winter. This year, the furnace would occasionally not kick on when temperature was below thermostat setting. I then reset the thermostat a degree or two and it would work. Never called for service.
After a 3 day Christmas trip, we returned to a house at 43*. Resetting the thermostat did not result in a working furnace. I could hear what sounded like a fan moving inside the furnace (not the blower). but the burner never ignited. When I turned the breaker off and then on, the burner fired. Called for service after that.
First service tech was (incorrectly) told by his dispatch that the breaker was tripping. He replaced pinched wires between the gas valve and burner enclosure. I came in the house as he was finishing and explained the actual problem. He said to call back when the problem reappeared.
Which happened today - 5 days later. The second service tech diagnosed a dirty flame sensor. He polished it and put it back in. The furnace seems to be working fine. The tech said that flame sensors get dirty and prevent firing, and that sometimes the sensors need polished as often as once or even twice a year. He said the same furnace can operate for years in one home without trouble, but in another the sensor can get dirty enough to block ignition on a yearly basis. He said that cleaning the sensor is part of a yearly maintenance routine sold by his company.
Could he possibly be right? Is Carrier actually marketing a product that will not last a year between service calls? The furnace has a five year warranty, but what good is that warranty to me if it doesn't apply when the furnace quits working? This seems to be more of a design defect than a maintenance issue. Or, could installation have been faulty, somehow allowing a dirty burn?
I live in central Ohio in a 25 year old development. All my neighbors and I get the same Columbia natural gas. 2 others on my block have the same Carrier furnace, and have not had this problem. Last winter was mild.
The tech charged me triple figures for his time, which I'll take up with the company. I know I did not pay for a service contract, but I did pay thousands for this system 19 months ago, and I don't think its unreasonable to expect it to work for more than one season before it needs repair. (Is polishing a dirty flame sensor "maintenance" or repair?)
Are high efficiency furnaces really this unreliable? Am I stuck with a lemon that will need service calls every year?