Dog House Flue

Do you live in a Split Level Ranch that was built in the late 1950’s through early 1960’s? If so, take a look at the picture above to see if it the flue termination for your furnace looks like the one shown. If it does, you need to go on the roof and into your attic to make sure that there isn’t any water damage to the wood or that the flue pipe itself isn’t rusted away.

The main concern with this type of flue is that the pipe terminates at the roof line in the attic. The exhaust gases then just draft into this dog house style of box which allows condensation to collect and as a result can damage the wood and can be a source of mold. If you or a previous owner updated the original furnace with an 80% efficient one, the condensation problem will be considerably worse than it was originally, if the flue termination wasn’t updated at the same time. Another problem with type of flue is that depending on the weather conditions, the flue gases might not totally escape the confines of the attic, which could possibly expose you to carbon monoxide.

It is fairly inexpensive to make the necessary updates to this style of flue to bring it up to today’s building codes, as long as there is no wood rot to deal with. To protect the integrity of your roof and the safety of your family, it’s good to know exactly how the flue gases are expelled from your furnace and hot water tank. If you need any help determining if yours is working properly, we would be glad to check it out for you.