Lochinvar 497 - 2067 Check for gas leaks, Check thermostat circuits, Check vent and air piping

6 Startup (continued)

Check for gas leaks

WARNING Before starting the boiler, and during initial operation, smell near the floor and around

the boiler for gas odorant or any unusual odor. Remove the front access panel and smell the interior of the boiler enclosure. Do not proceed with startup if there is any indication of a gas leak. Use an approved leak detection solution. Repair any leaks at once.

WARNING	Propane boilers only – Your propane supplier
	mixes an odorant with the propane to make
	its presence detectable. In some instances, the
	odorant can fade, and the gas may no longer
	have an odor. Before startup (and periodically
	thereafter), have the propane supplier verify
	the correct odorant level in the gas.

Check thermostat circuit(s)

1.Disconnect the two external wires connected to the enable terminals on the connection board.

2.Connect a voltmeter across these two incoming wires. Close each thermostat, zone valve, and relay in the external circuit one at a time and check the voltmeter reading across the incoming wires.

3.There should NEVER be a voltage reading.

4.If a voltage does occur under any condition, check and correct the external wiring. (This is a common problem when using 3-wire zone valves.)

5.Once the external thermostat circuit wiring is checked and corrected if necessary, reconnect the external thermostat circuit wires to the connection board. Allow the boiler to cycle.

Check vent and air piping

1.Inspect vent piping and air piping for signs of deterioration from corrosion, physical damage or sagging. Verify air piping and vent piping are intact and correctly installed per this manual.

Installation & Service Manual

Boiler operation

8.Verify that all adjustable points in the Operator Interface are set as required.

9.Boiler should begin the start-up process for the sequence of operation.

10.The boiler will ignite and operate to meet the system demand.

11.Ensure that inlet water temperature does not fall below the specified minimum for the boiler.

12.As system demand is satisfied, the burner will cycle off and the combustion air blower will run for a post purge operation before the boiler shuts down.

Start the boiler

1.Read and follow the Lighting Instructions in FIG. 6-1, on page 45.

If boiler does not start correctly

1.Check for loose connections, blown fuse or service switch off?

2.Is external limit control (if used) open? Is boiler water temperature above 200°F (93.3°C)?

3.Is thermostat set below room temperature?

4.Is gas turned on at meter or boiler?

5.Is incoming gas pressure less than 4 inches water column?

If none of the above corrects the problem, refer to the Maintenance Section of this manual.

WARNING The venting system must be installed so that it will prevent flue gas spillage and carbon

monoxide emissions, which will result in severe personal injury or death.

Placing the boiler in operation

Boiler operational checks

2.Turn the boiler main power switch to the “ON” position.

3.Confirm the settings of the temperature control.

4.Push the reset for the low water cutoff (if equipped).

5.Ensure that maximum flow to the boiler does not exceed 55 GPM on Models 402 - 752 and 90 GPM on Models 992 - 2072. Verify by checking temperature rise while burner is firing at 100% of rated input.

6.Install a manometer on the gas supply to the boiler and verify minimum gas supply pressure as the burner fires at 100% of rated input.

7.Verify operation of safeties as necessary (low water

cutoff, high limit, gas pressure, etc.,). 47