On Sun, 28 Nov 2004 15:31:28 GMT, derek wrote:

Hi Turtle
I got up in the attic and checked the air intake and it was wide open. I
could look down the pipe into the closet. I got up on the roof and
checked the exhaust and everything looked good as well. I can’t find any
kind of exhaust fan on the unit.
I posted some pictures he http://home.earthlink.net/~tig414/furnace/
What concerns me about this is why did a unit that operated for 30 years
suddenly develop a roll out problem. There have only been Three things
changed relating to the system. The thermostat, The main gas meter
outside the house, and the drive belt on the blower.

As I understand it, the rollout occurred when the gas valve shut down.
Something to check would be the pressure coming from the new gas meter
to the furnace. Excessive inlet pressure can sometimes overwhelm the
gas valve. Max inlet pressure varies with the valve model and is often
marked on the valve, but generally it should be 5-10" WC for a
residential gas valve.

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
http://www.techmethod.com