TESTING INLET PRESSURE
1. Note – gas pressure must be measured when unit is operating.
2. Set thermostat to “OFF”.
3. Remove top cover (2 screws at rear of heater, remove L/H side panel, remove front 2 screws hidden
inside side panel area)
4. Remove electrical enclosure screws and hinge cover forward.
5. Loosen screw from ⅛” brass test point located on inlet side of gas valve
6. Connect manometer tube to test point
7. Set thermostat to “ON” and wait for burner to ignite
8. Once burner has ignited, the manometer must indicate the nominal inlet pressure listed below.
9. Adjust inline pressure to meet minimum required pressure at main gas regulator. Do not adjust gas valve
settings..
10. Tighten test point screw.
11. Refit covers.
Required Inlet Static gas pressure (ie: when heater not operating)
Natural Gas 1.13 kPa minimum 5 kPa maximum
Propane 2.75 kPa minimum 5 kPa maximum
PERFORMANCE DETAILS
TO CHECK BURNER PERFORMANCE – Must be performed with a combustion analyser
1. Turn off power supply to pump and heater.
2. Turn off gas supply to unit.,
3. Remove top cover.
4. Remove electrical enclosure screws and hinge electrical cover forward.
5. Setup gas combustion analyser
6. Set up manometer to inlet side of gas valve.
7. Adjust gas rate screw 4 turns anticlockwise.
8. Turn on gas supply.
9. Turn on power to heater.
10. Start heater
11. Ensure heater is running at full fan rate.
12. Check inlet gas pressure is between max and min settings.
13. While heater is running adjust gas ratio screw to achieve a CO level of between 30ppm to 60 ppm for
Natural Gas models and between 50ppm and 150ppm for model 250 LPG
14. Check meter gas usage rate to ensure gas rate is as specified. Gas rate must be within +/-5% of nominal
rate.
15. Remove manometer and tighten test point.
16. Remove analyser.
17. Refit electrical cover.
18. Refit cover.
Gas inlet pressures (all models) during burner operation on high fire
Natural Gas 1.13 kPa
Propane 2.75 kPa
CO level (all models)
Natural Gas 30ppm minimum 60ppm maximum
Propane 50ppm minimum 150ppm maximum
Gas inlet rates
Viron 250 Natural gas & Propane 190mj/hr
Viron 350 Natural gas 290mj/hr, Propane 280mj/h
Viron 450 Natural gas & Propane 375mj/hr
Viron 550 Natural gas & Propane 490mj/hr
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