PVI Industries manual Burner Combustion Adjustment, PV500-45U06/12

19.When the blower motor starts, the flame control will check for a positive air flow. If the air switch or blocked filter switch (if equipped) is not made the blower will stay on for a period of time then lockout. To adjust the air- proving switch, turn the adjustment screw counter-clockwise until the air proving light comes on, then turn the screw one turn counter-clockwise. The blocked filter switch (if equipped) should only be adjusted when the filter is new. This switch should be turned clockwise until switch makes and then two additional turns. If the gas valves open and close intermittently during normal operation, adjust pressure switches to increase the operational threshold until this condition ceases. This procedure should be followed with every burner.

20.After the pre-purge, the flame control energizes the HSI for the heat up period, approximately 30 seconds. At the end of that period the gas valve is opened for approximately 4 seconds. After the burner has lit and the primary safety control senses a flame, the burner will remain on until the call for heat is satisfied or operation is interrupted by a safety device.

21.If the burner fails to light, the flame control will lockout. When this happens press the reset button on the front of the control to recycle burner and check for improper combustion or week flame signal as a possible cause.

22.Once the main burner flame is established the firing rate will be controlled by the TempTrac control. Refer to TempTrac manual PV500-41.

Burner Combustion Adjustment

Burner combustion should only be adjusted using a combustion analyzer. Do not attempt to adjust burner by sound or sight. With the burner firing, insert the combustion analyzer probe in the flue vent approximately two feet from the appliance. See Gas Train Illustration below for details.

With the burner firing and adjusted to low fire, adjust the regulator screw clockwise to increase gas flow or counter clockwise to decrease flow. The desired CO2 in the combustion products should be between 8.0 and 9.0% for natural gas, 9.5% to 10.5% for LP gas. Do not attempt to adjust combustion based on manifold pressure alone. Manifold pressure should only be used as a reference point.

a.Once the desired combustion is achieved at low fire, raise the burner firing rate to high fire. Adjust the valve orifice clockwise to reduce the flow of gas and counter-clockwise to increase the flow of gas in order to maintain the desired CO2 in the combustion products between 8.0 and 9.0% for natural gas, 9.5% to 10.5% for LP gas.

b.When high fire combustion has been reached and combustion is within the proper range, return to low fire to confirm settings again.

c.CAUTION: If at any point of the modulation range, carbon monoxide is in excess of 300ppm, contact PVI Industries customer service for assistance.

23.Enable or reconnect any BMS/BAS control interface removed prior to the setup and adjustment of each water heater.

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PV500-45U 06/12