We have radiant baseboard heaters, which has to be the oddest sounding way to heat a house. Instead of the cozy sound of a crackling fire or the logical sound of rushing air, it makes an assortment of gurgles, knocks and bangs like malfunctioning pipes.
The weirdest one is the one in our bedroom which, after careful contemplation, I have finally determined sounds like the drums in the deep in Moria. At least I think that noise is the heater.
I guess if orcs break into our room one night, we can't say we weren't warned.