pressure switch on gas furnace
 

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

pressure switch on gas furnace
 

wrote in message
...
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

My guess is that the blower that creates the pressure/ vacuum for that
switch to function is at fault. It's never advisable to disable safety
devices, but maybe it's time to try a new furnace tech

pressure switch on gas furnace
 

You've got a high efficiency furnace so the most of the heat has been
extracted from the exhaust. So it won't rise up the chimney--you have
to push it up.

The blower that does that is called an "inducer blower." When the
furnace gets a call for heat, it starts up the inducer to start
blowing air (either sucks it into the burners ahead of the flame or
blows it out after the flame--different mfgrs do it different ways).
Since the whole point is to create a "draft" up the chimeny (just like
using newspaper in your fireplace to combat the cold air rushing down
the chimeney, the furnace needs to know when it's accomplished that.
The pressure switch tells the controller board that there's sufficient
air movement to go ahead and fire up the ignitor and then open the gas
valve.

If your furnace has a few years under its belt, chances are the
inducer blower is weak. Technicans check that out by running an
amperage draw test on the motor. If it's using too much juice, they
replace 'em.

pressure switch on gas furnace
 

wrote in message
...
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

Just went through a furnace problem. Mine was the result of an igniter
failure. The igniter used in my furnace (silicon nitride) turned out to be
the most costly of all the ones that I looked up. The average igniter cost
anywhere between $30 to $50. Mine came along at $110 online and $134 at the
local HVAC company. those component prices seem way out of line.
MLD

pressure switch on gas furnace
 

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

pressure switch on gas furnace
 

On Tue, 13 Jan 2009 13:05:44 -0800 (PST), "
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?

Our 5-yo high efficiency gas furnace quit working recently, and the
cause was a slight sag in the exhaust PVC piping run (horizontal out
the side of the house) that apparently was not exhausting the fumes
and kept the pressure switch from activating the fuel (or something
like that). All is well now, no parts were replaced.

pressure switch on gas furnace
 

On Jan 13, 3:05*pm, "
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

This is condensing? Blockage or ice on air intake- exhaust is common,
an animal, bird can get in them if there is no screen. Get a different
pro to check the whole thing out, when is the last time it was cleaned
completly and gone over by a pro. You dont take off hoses or anything,
safteys are put in for a reason.

pressure switch on gas furnace
 

On Jan 14, 8:54*am, ransley wrote:
On Jan 13, 3:05*pm, "

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

This is condensing? Blockage or ice on air intake- exhaust is common,
an animal, bird can get in them if there is no screen. Get a different
pro to check the whole thing out, when is the last time it was cleaned
completly and gone over by a pro. You dont take off hoses or anything,
safteys are put in for a reason.

its just strange that it works fine during the day, but at night they
periodically have to turn it off and on. sucks even more since the
northeast is getting a cold spell at this time. no chimney its a
condo the vent goes outside and doesnt seem to be blocked cuz it comes
out just fine.

pressure switch on gas furnace
 

"ransley" wrote in message
...
On Jan 13, 3:05 pm, "
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

This is condensing? Blockage or ice on air intake- exhaust is common,
an animal, bird can get in them if there is no screen. Get a different
pro to check the whole thing out, when is the last time it was cleaned
completly and gone over by a pro. You dont take off hoses or anything,
safteys are put in for a reason.

If it's a condensing furnace then it might be important to know where the
condensate drain goes. If it's dumped outside and the water freezes at the
end of the drain line that could be a major reason for a furnace shutdown.
During the day it might be warm enough to prevent freezing. Just a thought.
MLD