What could cause a flame sensor to stop working so frequently


Over a year ago after a month in our new house, we came back one evening to a cold home and after some googling, I found out that the flame sensor was dirty and the furnace was starting the flame and then quickly puffing it out. I cleaned the flame sensor and everything was normal again for two weeks. The flame sensor would fail every two weeks and every time I would clean it up and put it back in and everything would be okay.

This made me very frustrated, so I talked to a number of HVAC stores, and none had any idea what was precipitating the situation. Finally, a lady at one HVAC store told me it was the lint from the laundry drier that happens to be too close to the furnace and that there is nothing that can be done about it if the laundry machines share a room with the furnace in the basement which is in fact the case in my house. Nevertheless, I bought a brand new flame sensor and replaced my sensor.

The new sensor held up fine for a month and then failed and needed cleaning and started failing every two weeks after the first cleaning.
I am now very frustrated and concerned about what would happen if I was to go on a prolonged vacation in winter. This would specially be a problem since my spouse is not handy and she would simply have to freeze waiting for an HVAC technician if this ever happened while I am away.

Is anybody else having the same problem?

Is there an easier longer-lasting solution?

I should mention that my furnace is high-E newly installed Goodman furnace running on natural gas in mid-western Canada (3 years).

Best Answer

Have you had a gas technician go over your entire combustion system?

I strongly suspect that something is not adjusted correctly, and you have excess soot production (lint seems like a red herring, frankly) which is making the sensor "dirty." It also means you are not burning your gas as efficiently as should be possible. This is almost certainly a problem with combustion, not the sensor. The sensor fouling is a symptom, not a cause.

I don't really regard this a great area for DIY - without the right tools, which cost more than most homeowners (including me) will spend, and the right training to go with them, screwing up combustion appliances though self-service is more common than tuning them perfectly. There's also "not creating a giant loophole for your insurance company if the house burns down" as a minor factor in that thinking. Having burners professionally serviced on a yearly basis is a minor expense, comparatively.

If (as is commonly the case with high-efficency burners) the furnace has both an air intake from and an exhaust to outside, the dryer lint really can't be the problem. Some sort of blockage of that intake could, however, potentially cause the problem you are having (insufficient air supply causing a rich, sooty flame; soot fouling the sensor.)