11. Tune the gas valve. For instructions, see
Adjusting the gas valve (EX 700, EX 850) on
.
12. Check for gas leaks.
6.3.3 Measuring the inlet gas pressure
To locate the inlet gas pressure test port on the EX 400 and the EX 500 models, see
.
To locate the inlet gas pressure test port on the EX 700 and the EX 850 models, see
.
6.3.3.1 Measuring the inlet gas pressure - EX 400 and EX 500
To perform a gas pressure test, you will need to use a flat head screwdriver and a digital
manometer. You will be measuring the inlet gas supply from the test port (see
). Do
not perform a test from the manifold gas pressure test port.
Ensure that you have a load configured (Reset Heating, Set Point, or DHW). This load should
be large enough to allow the boiler to operate at high fire for over 10 minutes.
1. Shut off the gas supply.
2. On the gas valve, loosen the inlet gas pressure test port screw counter-clockwise.
Figure 47
Location of inlet gas pressure test port
3. Attach the manometer to the inlet gas pressure test port.
4. Switch on the gas supply to measure the inlet gas pressure. The gas pressure for
natural gas should be around 7" wc at high fire and 11" wc for propane. If the gas
pressure dips below 3½" wc or exceeds 15" wc, the boiler will shut down. If this
occurs, you will need to reset the gas high or low pressure switch. For instructions,
see
Resetting the gas high / low pressure switches on page 77
5. After completing the inlet gas pressure test, switch off the gas supply.
6. Remove the manometer from the inlet gas pressure test port.
7. Tighten the bolt head using a flat head screwdriver.
72
Section: Boiler operation
Summary of Contents for EX Series
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Page 121: ...Appendices Wiring diagrams Figure 73 Controller electrical diagram 119 Appendices...
Page 122: ...Figure 74 Internal wiring diagram EX 400 and EX 500 models 120 Section Appendices...
Page 123: ...Figure 75 Internal wiring diagram EX 700 and EX 850 models 121 Wiring diagrams...
Page 124: ...Figure 76 Sequence of Operation 122 Section Appendices...
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