10 year old Carrier oil furnace. It is vented through a power side vent
through the side wall of the house (Tjurlund is the mfg of the venting
system). When the tstat calls for heat, the vent comes on. the primary
control never requests the burner to start. when I short out the T
terminals on the primary control, everything fires off perfectly (I do
annual nozzle and filter changes on all 4 oil appliances at my house). I
do not understand the wiring from the tstat to the furnace adequately. I
assume the tstat is working and assume that the problem is in the board.
the tstat goes into a board and the output of the board goes into the oil
primary control. dont know how to test to see if this is the case. I can
take photos of everything and email to anyone who understands this
Forced air? hot water? Zone valves with 'valve open' contacts?
In some situations (all?) with a forced draft, there is a mechanism to
make sure the draft is really there. On my gas hot water heater, it
used an overheat sensor, your unit may have something that checks for
the draft before allowing the unit to fire.
If you're into abuse, you can post this on alt.hvac, but there's a 90%
chance you'll only receive abuse.
Probably a bad sensor in the power vent unit that confirms the draft is
there before letting the burner run. Possibly a sail switch or a vacuum
switch and sensing tube. Try to find a manual for the power vent unit
online and it should show what it has for this safety sensor.
On Wed, 29 Nov 2006 06:18:00 -0600, " firstname.lastname@example.org"
I don't know much about this, especially for a furnace only 10 years
You know there is more to furnace cleaning than just that, right?
You may have to adjust the ignition electrodes, or at least verify
that their spacing is correct; or clean a second filter in the pump,
and you may well have to clean out the flue, and this fall, I
definitely had to clean out the tubes between the fire chamber and the
There were rocks in there, some almost as big as golf balls, made out
of heating oil. They looked like steel slag, or lava with steam holes
in the middle, but I could break them by squeezing. Still, they
clogged my exhaust and made lots of smoke come out.
I also tried to vacuum inside the fire chamber, with a hose attached
to my shop-vac with the soot proof filter bag, but I was not very
successful. I don't how important this is.
Plus the tech would throw a smoke-stick in there as the last step, but
I didn't have any smoke-sticks. I never got sure what they did.
Plus, there may be things that the tech did that I've forgotten to do.
Plus things he should have done but didn't. For example, only the
first guy ever used gauges. Those who came for the next 21 years just
looked at the flame and decided if they were happy or not. (Well,
they always were happy, I guess, because they never did any
adjustments.) I don't have gauges.
The first rebalanced the swinging damper using a guage, a later guy
taped the whole thing closed, a later one untaped it when I asked
about it being taped.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.