[A/S] Re: furnace

["j54mark" <jmrdse@xxxxxxxxxxx>]

If the exhaust is truly hot, not just lukewarm, then there is 
combustion going on.  If, then, the ducted air is cool, there is 
cause for concern, and possibly alarm.

1). The most likely problem is a duct somewhere that has worked 
loose, allowing your heated air to blow into a cabinet or storage 
area, or possibly even outside.  A large opening (rust?) in one of 
the pans for the water tanks will have the same effect.

2). Another possibility is a very dirty burner.  This would allow 
combustion to occur, but may not permit it to burn hot enough to heat 
the heat exchanger adequately.

3). A bad gas regulator would have much the same effect as in 2) 
above.  Try lighting all stove burners simultaneously and see if they 
burn strong and blue.  I don't think this is likely, as low gas 
pressure would probably prevent it from igniting altogether.

4). You might have a cracked heat exchanger.  This one worries me the 
most as it will pump CO into the living space and kill you.

Mark