John Wood Superflue Power Vent (75 Gallon) - Manual (Page 28)

V) OPERATION
Performance Checks
Burner Manifold Pressure
The burner operates at a manifold gas pressure of 3.5 in.
w.c. (0.9kPa) for natural gas and 10.0 in. w.c. (2.5kPa) for
propane gas. A 1/8” NPT port is provided on the gas valve
control for connection to a gauge to measure the pressure
(See Figure 20). The control valve has an internal pressure
regulator. Do not confuse the manifold pressure with the
supply inlet pressure. Return port plug upon completion of
tests.
Checking Input
Never exceed input shown on the rating plate. Ask your gas
supplier for the heating value of the gas you are using.
Check the input by ”clocking” the gas meter. Make sure no
other appliances are operating when the test is being done.
To ensure accuracy, clock enough gas so that the time is
greater than 60 seconds. Use the following formula to check
input. Check that your gas pressures are as previously stat-
ed.
Input in BTU/Hour =
Gas Heating Value* x Cubic Feet/Meters clocked
Seconds clocked/3600
*Gas Heating Value in BTU/cubic feet or cubic meters
1 cubic meter = 35.31 cubic feet
Checking burner flame
Superflue TM Water Heaters uses a cast iron burner. Access
the burner by lifting off the outer gas door and sliding open
the inner door located at the bottom of the water heater.
• For units with cast iron burners, the flame presentation
should be as shown in Figure 24. Adjustment is possi-
ble by changing the air shutter position on the burner
inlet. If the flame needs adjusting, loosen the two
screws and move the shutte (see Figure 25). If it is too
far open, the flame will lift or will be noisy; if it is closed
too far, the flame will be luminous and yellow. Once
proper flame is obtained, tighten the screws to secure
the air shutter.
Important: Always return the burner doors to their original
position.
VI) SERVICE AND MAINTENANCE
This section describes the routine service instructions to
properly maintain your heater and venting system.
Not Enough or No Hot Water
• Check that the water heater is operational.
• Check that the thermostat is set high enough.
• Check that you have not just run out of hot water due to
heavy demand. If this is a routine problem, it may indi-
cate an under-sized water heater.
• Have your gas company check input rate and water
heater operation.
• The ECO may have tripped open (LED indicator on con-
stantly). See ECO below.
Energy Cut-off Control (ECO)
This water heater is equipped with a control that has a built
in ECO (Energy Cut-Off). The ECO will shut the gas off,
should the outlet water temperature exceed 93° (200°F). If
the ECO has tripped, the entire gas control must be
replaced. For gas control replacement, contact your local
gas utility, or a qualified service technician. The replace-
ment control must be an identical model to the control that
has been removed.
CORRECT FLAME
SOFT BLUE
INCORRECT
FLAME LAZY
YELLOW
Figure 24 Flame Characteristics
BLUE TIPS
LIGHT BLUE INNER
CONES ARE SATIS-
FACTORY
PRIMARY AIR
CLOSED
OPEN
AIR SHUTTER ADJUSTMENT
FOR CAST IRON BURNER GOOD BLUE FLAMES
Figure 25 Cast Iron Burner
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