Your furnace is not one of those appliances that uses water for its primary function. Water leaking out of your water heater, for example, is a problem, but not an unexpected one since it heats water as its main function. Water leaking out of your furnace, however, seems like a very big problem since it does not use water in its primary function. If you have come home to a puddle under your furnace, what is going wrong?
Improperly Sized Flue Pipe
If your furnace is a newer installation or the flue pipe was recently replaced, it may be the wrong size. Typically, when this happens, it will create condensation that will then run back into your furnace and leak out of it. Your furnace will always create some condensation, but usually only in more extreme temperatures and not so much inside of the actual flue pipe.
Any condensation that a furnace does give off should be safely ferried away to a floor drain. However, if this has been blocked by various debris – which can be common – it will not drain away and may result in a worrying puddle around your appliance. This debris can build and block the drain for a long time, but you will likely only notice puddling on very cold or hot days in with the warm air meeting the cold air creating a large amount of condensation that cannot quickly evaporate.
If you have a whole home humidifier installed, your first suspect when you see water is that the humidifier is damaged and leaking into your furnace. Obviously any time your furnace is exposed to water, it is a serious problem. You will want to shut it off right away and contact our team. One of our experienced HVAC technicians can make sure that it is repaired before water exposure can do any serious damage to the internal parts.