rheem criterion gas furnace works intermittently

[Romeo Santos]

a month ago, a technician checked my furnace when it stopped working,
he found that the door panel was not properly closed so the switch was
cutting off, (gives you an idea how much i know) since then i have
been up in the attic a few times to make sure the door is tight when
the heat won't come on

this furnace has been erratic the last couple of weeks, the digital
thermostat is programmed at its factory setting, sometimes the heat
comes on and sometimes not, but the blower always works, when the heat
is set manually like at 72 it stops at 68, then i have to reset it
again to turn on the heat

the thermostat was installed only 6 months ago so i don't think it is
bad

i phoned the technician and he said i might have a bad switch and
quoted around $150 for the job

before having him do it, i thought i would get some advice
is this a job that is easy to do?
are there any other cause for the problem?
loose connections? venting?

any suggestion is greatly appreciated

[Robert Andrade]

Save your $150 bucks. If some things works on your funace such as you say
the fan, the the door switch is ok.
sounds like unit is locking out. Have teck check circuit board and flame
sensor.
Romeo Santos wrote in message <36d3bd47....@news.earthlink.net>...

[John Mills]

> >this furnace has been erratic the last couple of weeks, the digital
> >thermostat is programmed at its factory setting, sometimes the heat
> >comes on and sometimes not, but the blower always works, when the heat
> >is set manually like at 72 it stops at 68, then i have to reset it
> >again to turn on the heat

> >any suggestion is greatly appreciated

Sounds like a dirty flame sense rod. Located above the burners to the
left. Wipe off with steel wool (no soap). These boards will retry
later so if it later comes on, proves the diagnosis.

--
HVAC Advice, Pictures, Links
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[DnRhvac]

How old is this furnace? About 5 years ago Rheem used the Ignitor as the flame
sensor also. When you had a erratic operation like that it was usually caused
by a weak microamp signal back to the control board. Rheem fixed that with a
modification kit that included a seperate flame sensor, so that the ignitor
would light the furnace, and the flame sensor would sense the flame. If you
already have a flame sensor, it may be bad or dirty, or it could be the
electronic board. Let us know how you make out!