49
chaPter 13
air suPPLY
Maximum draft should not exceed 0.20 inches water column, if exceeded could cause solid fuel fire to
burn out of control.
Combustion Air Blower and Flipper Assembly
Principles
The combustion air blower and flipper assembly supply air for combustion inside
the firebox. The flipper assembly keeps air out of the firebox when combustion
is not needed. These components are removable and serviceable.
Operation of the Combustion Air Blower and Flipper Assembly
• When the water temperature reaches the
high water temperature
setting, the aquastat turns the blower
off
. At this point, the hinged
flipper falls shut, preventing air from getting into the firebox.
• When the water temperature reaches the
low water temperature
setting, the aquastat turns the blower
on
. At this point, the hinged
flipper opens from the force of the blower and allows air into the
firebox.
• The hinged flipper
must
completely open and close all of the time. When it is closed, it must seal
completely. If more than a “wiff” of smoke is coming from the chimney when the blower has been off for
approximately 10 minutes, this is a strong indication the hinged flipper is not shutting properly.
Maintenance / Result
• Lubricate the blower motor regularly.
• Clean the fin blades of the squirrel cage fan.
• Ensure the flipper assembly is clean and seals completely
when closed.
Steps to Maintain your Blower / Flipper Assembly.
1) Turn off the main power supply to the furnace.
2) Loosen and remove the two thumb nuts securing the
blower / flipper assembly to the large air tube, and remove the
blower / flipper assembly.
3) Lubricate the blower motor every six months with 10 to 20 drops
of SAE 10W or 20W non-detergent oil (ML Type) or with electric
motor oil in the appropriate oil holes
. the oil holes are on the
bottom of the blower.
4) With a small brush, scrape any dust or residue that has
accumulated on the fins of the blower.
5) With a scraper or brush, remove any residue built up on the flipper
assembly.
6) Ensure the flipper is resting completely on its seat. If it is not
resting completely, perhaps there is dust or soot built up on the flipper,
or some other obstruction not allowing it to close tightly.
7) Securely fasten the blower / flipper assembly back to the large airtube
ensuring there are no air leaks.
the FLiPPer Must OPerate PerFectLY Or PrOBLeMs QuicKLY arise.
Flipper Assembly
Combustion Air Blower
