On Thu, 18 Oct 2007 18:48:29 -0700, wrote:

Then I checked the electric box and as Edwin Pawlowski said in this
thread, voltage is low. It's not enough, only 14volts... why?
I've no clue, because I don't have much knowledge of the topic.


I had the same problem for a week now, pilot light on but no flame.
Then after some heroic fiddling around I have flame but have to turn
it off by hand, that is turn the regulator control from gas ON to
PILOT to shut off the main burners. As luck would have it the fall
weather turned really nice after an early near freeze. Therefore I
was no longer under the gun to fix it immediately. If I needed heat I
just turn it on long enough to warm up. I'm mostly at home all day
and night so there's no problem of anything (water pipes) freezing up.

I'll go straight to the things you can check out. In my case the
final problem was that the insulation for 24Vac wire leads to the
upstairs thermostat had baked hard and cracked. 25 years next to the
hot burner section of the furnace does that. It shorted taking out
the old style mercury switch thermostat. I'll have to replace that.
These are no longer available, mercury is a harzardous material under
current regulations I shall get a non programmable electronic
thermostat. I hate the programmable type as I can never remember how
to reset them for daylight saving time for example.

1. Go check all your wires and replace any that seem less than prime
condition Check that the 24Vac transormer and measure the voltages to
ensure they are all there. Measure the voltage output yourself. The
14V reported by your service guy doesn't sound right. The label on
your regulator should specify this (24Vac). If so replace with a 24
volt unit.

2. In case your thermostat is shot go to the furnace regulator and
disconnect one of the two thermostat wires on the regulator terminal
assigned to the thermostat. Then jumper the disconnected terminal to
the transformer (ie close the circuit without passing through the
thermostat.) If the burners fire up you have a bad thermostat.
Replace.

Correction. Do this jumper test first as this is easy to do.

3. Give the gas regulator a good thump with a rubber mallet. This
may loosen a stuck valve if that is the cause of your problem. That's
what the service technician did. It didn't solve my problem but
that's something you can do yourself and check it out.

4. Call your gas company emergency service to check out your furnace.
I was so freaked out by the horror servicemen from hell stories (eg
yours) that I resisted calling one. My gas company ATCO Gas of Canada
has a wonderful 24 hour emergency service. They came for all my three
calls (long story) within 3 hours.

4:1 The first call was when I lost my hot water heater flame too after
having shut off the gas supply to work on the furnace. The darn heat
regulator switch wouldn't turn far enough for me to reset ON the
safety shut off. All it required was to pop off the swich cover and
turn the switch stem by hand. He had too many calls and wouldn't work
on my furnace. No charge.

4:2 I couldn't for the life of me budge the gas regulator with a big
wrench to unscrew and replace it. I dared not use more force as the
burner manifold was already starting to twist and I dreaded breaking
anything. So I made another service call. Voltage checks OK. Good
thump didn't loosen stuck valve. Said I would have to replace the
regulator. I was too muddled to take up his offer to do the job then
and there. (I found out in 4:3 that it would have cost me only around
$5 more than I paid for a new regulator) I told him my problem with
uninstalling the regulator. He did it for me. I'll buy the new unit
and install it myself. No charge.

4.3 Bought a new regulator $183 incl tax and installed it. No main
burner flame. Voltages checked out OK. I had already spent enough
effort and time to have lost track of my trouble shooting steps and
options. Called ATCO Emergency Service. Guy came. Spotted crappy
thermostat wires. Did the jumper thingy. Saw burn marks on
thermostat dial. Problem solved. 30 minutes. No charge.

No high pressure sales from any of the three service guys to buy
unasked for equipment.

=================================================
From your post there won't be much youcan do besides the electrical
checks and the big thump. At least you will be satisfied that if its
a regulator problem swapping in a new regulator is the only fix a HVAC
guy can legally do. Phone up your gas company's emergency service and
find out what services they provide. The three different guys I had
were the most pleasant and helpful guys I have come across. They
didn't bat an eye when I told him my attempts at repairs and my intent
to replace the regulator myself. This gave me confirmation that what I
did was not some dumbfool thing.

Their emergency service is to restore gas service and simple fixes for
home gas fueled equipment - furnaces, water heaters, fireplaces. If
your installation needed major work requiring a tradesman to correct
that's not his job and he'll advise you.
================================================

I went to the appliance parts store to get a replacement regulator
before attempting to do any fancier repairs. My gas regulator model
is found in http://www.amresupply.com/category_view/H/HK,21,3 model
identified as SKU V800A1161.

The parts supplier can only sell the complete factory assembled unit,
no sub assemblies. By law he cannot sell any unit that has been
disassembled and reassembled. Once installed (used) he cannot take it
back for a refund. The service technician says the same thing. He
can only check the voltages and connections or change a whole
regulator. He cannot open up the regulator to do repairs. He doesn't
even know how the parts inside work though like me he must have opened
up a scrapped one to self educate. I shall write this up in due
course on what's inside and decide for yourself if you want give parts
repairs a shot.

Actually its quite simple. On the bottom of the regulator are four
long screws. Undo them, the cover plate (has smaller parts) and the
bottom half assembly should come loose (jiggle it) to expose a
teeter-totter assembly. The rubber valve at one end of this assembly
covers a gas orifice. Mine was slightly stuck and popped open when I
took off the bottom assembly. Had I not been alert I would have
likely missed noticing the stickiness. Not that it matters since
loosening it is the idea. The other subassemblies of the regulator
are very simple, non moving and built like a tank. They won't wear
out. There's nothing to repair. Messing with them will likely
introduce problems that were not there originally. All parts are
keyed to prevent incorrect reassembly.

If you ever do major work like I shut off the main gas supply and the
electrical power to the furnace before working on it. Shutting the
gas off for an extended period causes the safety shutoff at the
regulator next to the gas meter to set. Very little gas flows into
the gasline. The dinnerplate sized gas regulator has a center stem
(like a mushroom stem) Unscrew the thimble shaped cap at the tip. It
will reveal a metal stem. Pull on it and it will feel like popping a
suction cup. This resets the safety and lets the gas flow into the
line again.