Lochinvar 402 - 2072 Troubleshooting, Check control module fuses, Before troubleshooting

Copper-fin II/IIE Boiler and Water Heater Service Manual

3 Troubleshooting

￿WARNING

Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Always disconnect power to the appliance before servicing. Failure to comply could result in severe personal injury, death, or substantial property damage.

Check control module fuses

NOTICE	ALWAYS check control module fuses before
	replacing control module or any major
	components (blower, etc.). If one of these
	fuses is blown, it can prevent the control
	module or other components from operating.

Never jumper (bypass) any device except ￿ WARNING for momentary testing as outlined in the

Troubleshooting chart. Severe personal injury, death, or substantial property damage can result.

Before troubleshooting:

1.	Have the following items:
	a.	Voltmeter that can check 120 VAC, 24 VAC, and
		12 VDC.
	b.	Continuity checker.
	c.	Contact thermometer.
2.	Check for 120 VAC (minimum 102 VAC to maximum

1.Turn OFF the power to the appliance at the external line switch.

2.Remove front access cover.

3.Inspect fuses F2, F4, F5, and F6, see FIG. 3-1 below.

Figure 3-1_Control Module Fuses

F6

5 AMPS

	132 VAC) to appliance.
3.	Make sure thermostat is calling for heat and contacts
	(including appropriate zone controls) are closed. Check for
	24 VAC between thermostat wire nuts and ground.
4.	Make sure all external limit controls are installed and
	operating.

Check the following:

F4

5 AMPS

F2

3.15 AMPS

F5

5 AMPS

1.Wire connectors to control module are securely plugged in at the module and originating control.

2.Gas pressures:

Refer to the Gas Connections Section of the Installation and Operation Manual for detailed information concerning the gas supply.

4.The appliance is shipped with four (4) spare fuses in a plastic bag attached to the control panel.

5.If necessary, replace open fuse (F2 is 3.15 amps and F4, F5, and F6 are 5 amps).

Note: Fuses F2 - F6 are all slow blow fuses.

￿WARNING

Do not jumper fuse or replace with any fuse except as specified. Failure to comply could result in severe personal injury, death, or substantial property damage.

6.Install front access cover after fuse inspection.

7.Restore power to the appliance at the external line switch and verify boiler/water heater operation (Start-up Section in the Installation and Operation Manual) after completing boiler/water heater service.

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