Additional Precaution For Excess Flow Valve (Efv); Checking Gas Pressure At The Water Heater For Proper Operation; Setting And Verifying The Combustion Setting - Westinghouse Premium WGRT 199 Series Installation, Start-Up, Maintenance, Parts, Warranty

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C. Additional Precaution for Excess Flow Valve (EFV)
If an excess flow valve (EFV) is in the gas line, check the manufacturer's
minimum and maximum flow capacity ratings. An improperly sized
EFV will not allow for a full flow of gas to the water heater and will
cause the water heater to malfunction. See Figure 44.
Figure 44 - Excess Flow Valve (EFV)
D. Checking Gas Pressure at the Water Heater for Proper
Operation
NOTE: Refer to Figures 45 and 46 when checking gas pressure.
Loosen the bolts before checking the gas inlet pressure.
1. The water heater and its individual shutoff valve must be
disconnected from the gas supply piping system during any
pressure testing of the system at test pressures greater than ½ psi
(3.5 kPa).
2. The water heater must be isolated from the gas supply piping
system by closing its individual manual shutoff valve during any
pressure testing of the gas supply piping system at test pressures
equal to or less than ½ psi (3.5 kPa).
The minimum and maximum inlet gas line pressures must meet the
requirements shown in Table 26.
Natural or LP Gas
Minimum Pressure
Maximum Pressure
Table 26 - Gas Pressure Requirements
Do not fire (operate) the water heater until all connections have
been completed and the heat exchanger is filled with water. Doing
so will damage the water heater and void the warranty.
Offset Screw
Figure 45 - 150 Model - Gas
Valve Detail
E. Setting and Verifying the Combustion Setting
1. After the water heater has fired, flip DIP switch seven (7) to the
ON position (low fire). Proceed to check heater combustion values.
NOTE: Use a calibrated combustion analyzer to ensure CO and CO2
values are within the range shown in Table 27.
If the readings obtained are lower or higher than the combustion
readings in Table 27, use a 4mm Allen key to adjust the offset screw
in a clockwise (positive) or counterclockwise (negative) direction
(approximately 1/4 turn). See Figures 45 and 46. Check your
whl-004 Rev. 000 Rel. 013 Date 5.1.18
3.5" WC
14"WC
Offset
Screw
Adjustment
Figure 46 - 199 Model - Gas Valve
Detail
combustion values. Repeat this procedure until the values obtained
on the calibrated combustion analyzer agree with those stated in Table
27.
It is required to use a calibrated combustion analyzer to verify final
adjustment according to the combustion chart (Table 27). Failure to
do so could result in serious personal injury or death.
NOTE: If the heater makes a whistling sound (harmonics) at low fire,
adjust the offset screw in a clockwise (positive) direction (approximately
1/8 turn). Check your combustion values and ensure they agree with
those stated in Table 27 before proceeding.
2. When low fire settings have been obtained, flip DIP switch seven
(7) to its original (OFF) position. This will return the heater to normal
operation.
3. Flip DIP switch six (6) to ON (high fire). Again check combustion
readings with a calibrated combustion analyzer.
NOTE: DO NOT adjust the gas valve offset screw at high fire. The offset
screw is only used to adjust combustion values at low fire.
4. When complete, flip DIP switch six (6) to its original (OFF) position.
This will return the heater to normal operation.
5. Allow heater to operate normally. Ensure it is operating properly.
6. Reinstall the heater front cover.
7. Use a Phillips Head screwdriver to reinstall the heater top cover.
It is very important that the combustion system be set within the
recommended CO measurements listed in Table 27. Visually looking
at the burner does not determine combustion quality. Failure to
measure combustion with a calibrated Combustion Analyzer and
set the throttle within the recommended CO measurements could
result in property damage, severe personal injury, or death.
Natural Gas
Fan Speed Low
CO PPM <60
CO (%) 8 - 10 8 1/2 - 10 1/2 9 - 10 1/2 9 1/2 - 10 1/2
2
Table 27 - Combustion Settings
LP Gas
High Low High
<200 <60 <200