Re:Ten year old DC90 Keeprite NTGM 125EKA manufacturer is shown as Inter-City with aircon
My temperature limit-switch kept popping (the one on the burner box) because my furnace was overheating. I tried all the reasonable things including checking the exhaust path for obstruction, checking the air filter and the registers. I also checked for a clogged exhaust fan drain - nothing worked.
Then I decided to take a look at the aircon evaporator to see if it had become clogged over ten years of use. There was no service access - I had to unbend sheet metal seams to get at it.
Looking inside I found it was heavily clogged with 'felt' (compacted dust) and it took me an hour to clean it using a vacuum line and a brush and a mirror - the stuff was pretty well stuck on.
The furnace now works better than I can remember and the overheating is finished.
My question - this looks like a sensible service job, to be done maybe every 2 years. If it isn't done the waste of gas and electricity (heating and cooling) will be major. What would a service tech do in such a case? I can't see them doing what I had to do!