Originally Posted by
seriph1
So many variable, but it sounds to me like the main duct has fallen off, which is what happened to ours at first..... the heat melted the crap gaffer tape they used and down she came ..... went into the roof space and it was lovely and warm ...... the heating bill that month was something to be believed! I suggest getting up in the roof and checking that first. After that, if you can verify that the fan is operational, it may be that the unit is 'cycling' but not getting to full throttle so to speak. This is what happened in our case .... we could hear it running and all that but no joy out of the ducts. I bought a replacement thermocouple and presto..... then I bought another for the next time it fails.