It's C-O-L-D

[96fleet]

Well cool to say the least. I have a '96 fleetwood brhm. with a heating problem, First of all i am in Canada and heat is essential. There is just a small amount of lukewarm air coming from the system, with a larger amount of cool/cold air, the heater hoses are warm/hot butstill no heat, i have changed the thermostat and still, no heat ??? Has anyone any suggestions?? Occasionally the heater works fine, but is cold most times. Seems almost like there is a fresh air door that is stuck open? Could it be? and if so, where is this door to be found?
Thanks, Hoping to get Warm.

[HotRodSaint]

Clogged heater core?

I flushed my system last year to fix this problem. It then happened again this year. I had the heater core replaced this time.

I read that clogged heater cores are a problem with the B and D body cars. The armchair engineering theory is that the 'clay tablet' used with the coolant and the design of the heater core don't like each other.

Some people just flush there system every year. Which if it works, is certainly cheaper than replacing a heater core.