wrote:
A little help here.. I have a gas furnace about 13 yrs old, and it
runs most of the time. the times it doesnt it seems that the pressure
switch is not working. i would take the little hose off it for a
second and then it turns on. i replaced the switch with another one,
not exactly the same it was .30 vs .35 plumbing store said it was
close enough, but that didnt make it go on. what else could be the
problem? is it bad to keep the hose off so it works everytime?
the furnace guy tried to charge me over 1000 total, 100 for
diagnostic, 470 for ignitor, (which works) and pressure switch another
470, which i purchased for 40. some garbage huh?
thanks

What I have seen happen is the metal tube
where the hose slips on the draft inducer
will get clogged. A stiff wire like #12
copper or sometimes a piece of coat hanger
can be used to clear the metal tube. You
can pull the tube from the switch and listen
for air flow when the draft inducer turns on.
Some pressure switches work on a drop in
pressure rather than an increase in pressure
and you will have to get the correct switch
or one that has a double throw micro switch.
I'm assuming that your furnace is similar to
the one on this site:

http://tinyurl.com/7mzmap

The prices given to you by the repairman
are insane. Even the most crooked companies
around here aren't that brazen. Me and my
friends would charge under $200.00 for a
repair like that.

TDD