Specifications

LWLCWH COLUMBIA BOILER COMPANY REV. 13106
14
Gas lines should be tested for leaks. Your gas company may wish to witness this test. Do not exceed
the maximum pressures allowed by the valve train.
Additional gas piping information is included in the burner section of this manual.
COMBUSTION AIR
It is essential that provisions are made for a fresh supply of outside air into the boiler room to insure
complete combustion, proper boiler efficiency, and a clean fire. Sufficient makeup air also helps pre-
vent nuisance shut-downs due to excessive combustion byproduct build-up on burner parts. Outside
air may be provided through ducts, fixed louvers or motorized louvers.
A rule of thumb for calculating fresh air openings to the outside is 63 sq. in. for every 100,000 BTUH
gross output, or 21 sq. in. per boiler horsepower. The result of the above calculation is expressed as
free area, meaning no restrictions of any kind. If louvers or screens are used over combustion air
openings, calculate the percentage of free area to allow for these restrictions.
Do not have exhaust fans in the immediate proximity of the boiler room if at all possible, as they will
cause a reversal of draft through the boiler when the burner is cycled off. This draft reversal draws
heat from the combustion chamber back through the burner. This heat will deteriorate burner com-
ponents prematurely, and eventually, burner operation will fail. The boiler room should experience a
positive pressure when the burner is not firing.
In situations where a boiler room experiences a negative pressure, use a direct air intake. A direct air
intake uses an adapter over the burner fan intake housing to draw in outside air through duct work,
from an external source. Consult burner manufacturer for parts and availability.
Important Note: Surface discoloration of the building may
occur due to improper boiler/burner adjustment and mainte-
nance. Columbia Boiler Company will not accept any liability
for such discoloration.