Page 18
FIGURE 18
MANUAL MAIN SHUT-OFF VALVE
WILL NOT HOLD TEST PRESSURE
IN EXCESS OF 0.5 PSIG (14”W.C.)
GAS VALVE
CAP
GAS PIPING TEST PROCEDURE
FIELD PROVIDED
LINE PRESSURE TAP
When checking piping connections for gas leaks, use pre
ferred means. Kitchen detergents can cause harmful corro
sion on various metals used in gas piping. Use of a specialty
Gas Leak Detector is strongly recommended. It is available
through Lennox under part number 31B2001. See Corp.
8411-L10, for further details.
Do not use matches, candles, flame or any other source of
ignition to check for gas leaks.
D- Gas Pressure Adjustment
Gas Flow (Approximate)
TABLE 9
GAS METER CLOCKING CHART
EL180UHNE
Unit
Seconds for One Revolution
Natural
LP / Propane
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-040
90
180
N/A
N/A
-060
60
120
150
300
-080
45
90
112
224
-100
36
72
N/A
Natural-1000 btu/cu ft LP /Propane - 2500 btuh/cu ft
Furnace should operate at least 5 minutes before check
ing gas flow. Determine time in seconds for
two
revolu
tions of gas through the meter. (Two revolutions assures a
more accurate time.)
Divide by two
and compare to time
in table 9. If manifold pressure matches table 10 and rate
is incorrect, check gas orifices for proper size and restric
tion. Remove temporary gas meter if installed.
NOTE
- To obtain accurate reading, shut off all other gas
appliances connected to meter.
E- Supply and Manifold Pressure
Supply Pressure Measurement
A port on the inlet side of the gas valve provides access to
the supply pressure tap. See figure 16. Loosen the screw
and connect a manometer to measure supply pressure.
See table10 for supply line pressure. Tighten screw after
measurements have been taken.
Manifold Pressure Measurement
To correctly measure manifold pressure, follow the steps
below.
1 - Remove the threaded plug from the outlet side of the
gas valve and install a field-provided barbed fitting.
Connect measuring device “+” connection to barbed
fitting to measure manifold pressure.
2 - Start unit and allow 5 minutes for unit to reach steady
state.
3 - After allowing unit to stabilize for 5 minutes, record
manifold pressure and compare to value given in Ta
ble 10. Make manifold adjustment if necessary.
4 - Shut unit off and remove manometer as soon as an ac
curate reading has been obtained.
5 - Start unit and perform leak check. Seal leaks if found.
.
TABLE 10
Supply Line and Manifold Pressure
Honeywell Gas Valve
Natural
LP/Propane
Manifold
Supply
Manifold
Supply
040
1.6 - 2.0
4.5 - 13.0
N/A
N/A
060, 080
3.2 - 3.6
4.0
11.0 - 13.0
100
3.2 - 3.6
4.5 - 13.0
N/A
N/A
IMPORTANT
For safety, shut unit off and remove manometer as
soon as an accurate reading has been obtained.
Take care to replace pressure tap plug.
F- Proper Combustion
Furnace should operate a minimum 15 minutes with cor
rect manifold pressure and gas flow rate before checking
combustion. Take combustion sample beyond the flue out
let and compare to the tables below. The maximum carbon
monoxide reading should not exceed 100 ppm.
TABLE 11
EL180UHNE Unit
CO
2
%
For Nat
CO
2
%
For LP
040
6.5 - 7.5
N/A
060
7.5 - 9.0
080
7.5 - 9.0
100
N/A
The maximum carbon monoxide reading is 100 ppm.
G- High Altitude
Units are
NOT
approved for installations over 4500 ft