Troubleshooting guide

PV500-17 07/13 Section 17
12
MAXIM
AXIAL FLOW GAS BURNER START-UP (continued)
18. Check flue gases with a flue analyzer to
make final settings of the air shutter.
a. The readings need to be taken from a
hole in the vent several inches above the
heater vent connection, but before draft
regulator.
b. Insert draft gauge into the 1/4" test
opening in the stack. Draft in stack should
read -.02" to -.06" W.C. Adjust draft
regulator, if installed.
c. When water in the tank is above 120°F,
insert analyzer or O
2
tester in 1/4" test
opening and take O
2
reading in
percentage.
d. Gradually close air shutter, taking O
2
reading at each adjustment of air shutter
until optimum O
2
% (4-6%) is reached. If
O
2
% decreases, open air shutter to last
reading where the greatest reading is
achieved.
e. Insert CO tester in 1/4" test opening and
take CO reading. CO should not exceed
.03%. A reading greater than .03%
indicates lack of air. Open air shutter
slightly and take readings until CO is
within proper range. Optimum reading is
no CO.
f. If air shutter was changed during CO test,
take a final O
2
reading.
g. Insert CO
2
tester in 1/4" test opening;
record in percentage.
h. Insert stack temperature gauge in 1/4"
test opening and read gross stack
temperature; maximum gross stack is to
be 450°F, minimum net stack is to be
300°F. (NOTE: net temperature is the
total stack temperature, less room
temperature.) If an excessively high
gross stack temperature is recorded,
check the flue tubes for turbulators.
i. Make sure the air shutter is locked
securely in place.
19. On burners with pilots, recheck pilot to make
sure its operation has not deteriorated if
adjustments are made to the air shutter. To
do this, shut off the main valve, check the
flame response signal by cycling the burner
through several lightoffs.
20. Check each operating and limit control to be
sure they function properly by lowering and
raising the temperature setting on each
control, causing the burner to cycle on and
off.
IMPORTANT
During the initial firing of the burner, smoke
that is not related to the burner will be
emitted from the heater. This is normal during
"burn in" and could possibly continue for
several hours.
21. Record the following information for future
use:
A. Air shutter position________________
B. Manifold gas pressure________"W.C.
C. Stack draft_________________"W.C.
D. O
2
reading_______________%(4-6%)
E. CO
2
reading______________%(8-9%)
F. CO reading________%(less than .03%)
G. Stack temperature:
Gross _______________________°F.
Less ambient__________________°F.
Net__________________________°F.
H. Combustion efficiency___________%