It could also be insufficient draft, but this is usually accompanied by the odor in the room when combustion occurs which you didnt mention, and with a three story flue isnt likely.The cleaning and thermocouple replacement is simple.

Sometimes the failure has nothing to do with any components within the heating system itself; I had a failure caused by an empty plastic grocery bag getting sucked into the opening on the air intake on a furnace on a windy day - no air for combustion causes unit to not fire up.

The internal combustion engine is old technology that needs to be replaced with high performance electric - not wimpy electric as they're trying to sell us now.

My parents live in Lake Havasu......and I think I have actually witnessed a couple of people spontaneously combust, or it was just an hallucination from heat exhaustion.....either way, it is hot in the summertime!!!

I'm concerned about my properties flooding, my tenants wiping feces on the wall, my tenants losing their job, my properties spontaneously combusting...but not that.

I’m a project manager for a global combustion and emissions controls company.

If all of this wasn’t bad enough, my job was outsourced to India just prior to the “dot-com” bust leaving me and thousands of others unemployed.

Because of electricity generation and transmission losses, electric heat is often more expensive than heat produced in homes or businesses that use combustion appliances, such as natural gas, propane, and oil furnaces.If electricity is the only choice, heat pumps are preferable in most climates, as they easily cut electricity use by 50% when compared with electric resistance heating.

Martin Looks like it is correlated and or circumstantial to local dot com bust and GFC.

Real scam - carbon monoxide is a by product of the combustion process.