Burnham L7248 manual III. Operating and Service Instructions, Press RED Reset Button

III. Operating and Service Instructions

WARNING

All boilers equipped with burner swing door have a potential haz ard which can cause severe property damage, personal injury or loss of life if ignored. Before opening swing door, turn off service switch to boiler and disconnect two halves of Burner Swing Door Interlock wiring harness to prevent accidental firing of burner outside the combustion chamber. Be sure to tighten swing door fastener completely and reconnect two halves of Burner Swing Door Interlock when service is completed.

1.ALWAYS INSPECT INSTALLATION BEFORE STARTING BURNER.

2.FILL HEATING SYSTEM WITH WATER.

NOTE: It is important to properly remove the oil and dirt from the system.

CLEAN HEATING SYSTEM If boiler water is dirty, refer to step 13 for proper cleaning instructions.

A.Fill entire Heating System with water and vent air from system. Use the following procedure on a Series Loop or Multi-Zoned System installed as per Figures 4 and 5, to remove air from system when filling:

(1)Close isolation valve in boiler supply piping.

(2)Isolate all circuits by closing zone valves or balancing valves.

(3)Attach a hose to hose bib located just below isolation valve in boiler supply piping.

(Note - Terminate hose in five gallon bucket at a suitable floor drain or outdoor area).

(4)Starting with one circuit, open zone valve.

(5)Open hose bib.

(6)Open fill valve (Make-up water line should be located directly above isolation valve in boiler supply piping).

(7)Allow water to overflow from bucket until dis charge from hose is bubble free for 30 seconds.

(8)Open zone valve to the second zone to be purged, then close the first. Repeat this step until all zones have been purged, but always have one zone open. At completion, open all zone valves.

(9)Close hose bib, continue filling the system until the pressure gauge reads 12 psi. Close fill valve.

(Note - If make-up water line is equipped with pressure reducing valve, system will automati- cally fill to 12 psi. Leave globe valve open).

(10)Open isolation valve in boiler supply piping.

(11)Remove hose from hose bib.

3.CHECK CONTROLS, WIRING AND BURNER to be sure that all connections are tight and burner is rigid,

that all electrical connections have been completed and fuses installed, and that oil tank is filled and oil lines have been tested.

4.LUBRICATION — Follow instruction on burner and circulator label to lubricate, if oil lubricated. Most motors currently used on residential type burners employ permanently lubricated bearings and thus do not require any field lubrication. Water lubricated circulators do not need field lubrication.

Do not over-lubricate. This can cause as much trouble as no lubrication at all.

5.ADJUST CONTROLS SETTINGS with burner service switch turned “ON”.

A.SET ROOM THERMOSTAT about 10° above room temperature.

B.PRESS RED RESET BUTTON.

C.On WATER BOILERS WITHOUT TANKLESS HEATERS equipped with L7248 electronic aquastat controller, set High Limit (HL) at 180°F. This temperature can be varied to suit installation requirements. L7248 controller has the High Limit adjustment range from 180°F to 240°F (82°C to

116°C). High Limit Differential is fixed at 15°F

(8°C).

D.ADJUSTING AQUASTAT CONTROLLER SETTINGS. To discourage unauthorized changing of Aquastat settings, a procedure to enter the ADJUSTMENT mode is required. To enter the ADJUSTMENT mode, press the UP, DOWN, and I buttons (refer to Figure 12) simultaneously for three seconds. Press the I button until the feature requiring adjustment is displayed:

•HL_­  High Limit.

•°F  °C.

Then, press the UP and/or DOWN buttons to move the set point to the desired value. After 60 seconds without any button inputs, the control will auto- matically return to the RUN mode.

L7248 Aquastat Controller will not display Low Limit and Low Limit Differential adjustment features.

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