My house is 9 years old. About 5 years ago the Lennox gas furnace began to go into lockout. The problem was diagnosed as a dirty flame sensor. Shortly after, the same problem occurred with the Rheem gas water heater which is near, but not next to the furnace. As a result, the flame sensors on both have to be cleaned or replaced at least twice a year.
The first time I contacted Lennox customer service they advised a reconfiguration of the furnace exhaust/air intake. After that didn't help, I sent Lennox 4 of the replaced flame sensor rods to be analyzed; I never heard back.
One service person talked about fumes from cleaning supplies, paint, even carpeting which may be contributing. Another service person said this flame sensor problem is common and I should expect to have it cleaned at least once a year.
My current plan is to replace both items because at least I'd have a functional warranty. But is this saga familiar to anyone? Thank you for your feedback.