Lennox Whitfield Optima 3 does not stay running frustration! Anyone see this?

Hello
This 20 year old Optima 3 Insert pellet stove was in very good shape and fairly clean. We did go thru it and like it says in the manual, cleaned all the parts stated below. Since the photo eye was suspect and a little skanky, I did the eye bypass with the ceramic low limit snap disc for good measure and ease of future maintenance. However after it fired, the pellets did stop feeding and it shut down with the stove having a big lazy flame!
It is very interesting that the very 1st troubleshooting measure is exactly that issue! I did notice that under the top baffle plate in the fire box had very little room for the air to flow coming up from the hot fire in the burn pot and getting in back of the wall behind the fire brick to continue on to the exhaust blower??
I finally put the meter on the vacuum switch and found the exhaust blower which was good and running well was not tripping the vacuum switch so the normally closed vac switch working on positive pressure never opened the contacts? I then put the manometer on the nipple (which was cleaned out very well) going to the vac switch and found the pressure to be extremely low 0.03 In-Wg. I also tried a new vacuum switch and that did not trip either. I know the Whitfields during the startup cycle bypass the safety switches so I also checked and replaced the Hi Limit snap disc for good measure. Still it did not run long after startup!
So we wheeled in the compressor and blasted every little crevice at the top of the firebox and tested the stove one last time. Even though the pressure at the nipple did not come up alot it was enough to trip the vac switch and now the stove runs well with a nice crisp flame!

Has anyone else seen this on a Lennox Whitfield Optima 3 or Profile 30 pellet stove?


from Owners manual page 30
ROUTINE MAINTENANCE
Pull Scraper Rod out & in several times
REMOVABLE BAFFLE PLATES (All Models)
At least once a year, the baffle plates (located in the
firebox below exchange tubes) should be removed
for cleaning (vacuum out, then reinstall baffle plates)
Removing Baffle Plates
The baffle plates contain keyhole slots allowing the
screws to remain in place while removing the baffle. Lift
each plate up and forward until screws release through
the keyhole slots. Remove baffle plates diagonally
through door opening

from Owners manual page 31
EXHAUST PASSAGES AND VENT PIPE (All Models)
Inspect frequently and clean when necessary. Fly ash will
accumulate at all bends in the exhaust system.

ASH CLEAN-OUT PORTS
Make sure stove is cold. Ash clean-out ports must be
cleaned as part of routine maintenance

REMOVE COVERS AND
VACUUM OUT FLYASH -
Loosen screws (1 per
clean-out) and lift each
plate out. Use an ap-
proved ash vacuum or
brush
to
remove
ash.
After
cleaning,
replace
clean-out
plates
and
tighten screws

From the Owners Manual Page 39
Unplug Appliance Before Performing Any Troubleshooting or Maintenance

TROUBLESHOOTING
Unplug Appliance Before Performing Any Troubleshooting or Maintenance
PROBLEM
CAUSE(S)
1. Fire burns with a
There is insufficient combustion air.
lazy orange flame.
Pellets build up in
the grate and there
is excessive glass
soot that is difficult to
remove
(Ash
and
soot are a product of
combustion with any
wood products, so
some build-up on the
glass is normally)

CAUSE(S)
1. Fire burns with a
There is insufficient combustion air.

SOLUTIONS
Lack of maintenance (clean Ultragrate, clean-out ports, exhaust
flow passages, venting system, exhaust blower intake, etc.
Remove any clinkers or ash from the bottom of the Ultragrate
that might be obstructing the primary air holes.
Check that the heat exchange tubes are not coated with ash.
Clean internal exhaust ducts.
Check gasket seal around the door. Use a thin strip of paper, 1
in. wide. Open the door and close it on the paper strip. A slight
friction should be felt when the paper strip is pulled. Repeat this
process at various locations around the door gasket. Replace
the door gasket if necessary.
Check gasket around ashpan.
Check for blockage in the air inlet tube or exhaust pipe. Clean
as Necessary.
Inspect glass seal to ensure that it is in good condition and is
properly seated to the door.
Fuel trim may need to be adjusted down for faster feeding fuels.
Change to a better grade of fuel if necessary.
Check that the damper has been opened enough for the amount of
fuel fed.
Have Your Authorized Lennox Hearth Products dealer check your
exhaust blower for proper operation.
The venting system design is too restrictive (call your authorized
Lennox Hearth Products Technician to evaluate how the installation
can be corrected to satisfy the exhaust flow requirements of the
appliance).
Refill hopper.
See (Pellets will not feed) this page.
Allow stove to cool for 1 hour and re-light. If the stove has been
operating at a medium to high burn rate and the room air blower has
been turned down low then the fan should be turned up higher. If
this problem persists (particularly at lower burn rates) then the high
limit disc should be replaced by your authorized dealer.
Adjust the damper to reduce combustion air flow.
Refill hopper.
Check to be sure that there is no blockage in the pressure tap or
hose. Have your authorized Lennox Hearth Products dealer diag-
nose the problem and clean or replace any necessary parts.
If new installation check for excessive 90˚ bends, long horizontal
runs or excessive vertical run of 3" pipe. Possibly change to 4" pipe.
If older installation check for excessive ash accumulation in pipe or
other obstructions. Clean out pipe.
Check to see if thermostat is set to low or if sun is shining directly
on thermostat.
Re-install wires.
Allow stove to cool. Increase room air blower setting.
Gently tap the auger motor.