Beckett CF2500 manual Set High-fire Air, Set Low-fire Air, If burner stops during venting

Section: Prepare the Burner for Start-up

6.If the burner motor does not start, reset the motor overload switch (if so equipped) and press the reset switch of the burner primary control.

7.Vent the fuel unit as soon as the burner motor starts rotating. To vent —

○Attach a clear plastic tube to the air bleed valve (Figure 9 or 10 as applies, item p).

○Place the end of the tube in a container to catch the oil. Then loosen the fuel unit air vent valve.

○Tighten the air vent valve after all air has been purged.

○IF burner stops during venting —

-The burner primary control will lockout if

flame is not established within its time limit. This is typically 15 seconds for 7505 primary controls, but may be less for other flame supervisory controls.

-The burner may lockout several times during the period needed to purge all the air. To extend air venting time, press the red reset button for 1/2 second during the prepurge cycle to continue purging with 7505 controls.

○IF burner stops after flame established —

-Additional venting is probably required. Repeat the air venting procedure.

8.Once flame is steady, proceed to the ‘Set High-fire Air’ Section air.

Set High-fire Air

1.Allow the burner to run at low fire until the appliance has warmed sufficiently.

2.Visually check the flame. The flame should not be dark orange or smoky. If the flame appears to be smoking, increase the amount of air by readjusting the damper indicator to a higher number.

3.Once the appliance has warmed, the high-firesetting can be checked and adjusted.

4.Locate the approximate air adjusting plate setting for high fire in Table 4.

5.Place the low-fire hold switch in the high-fire position. The damper motor will begin to rotate after four seconds.

6.Use combustion test instruments to adjust the burner.

a.Adjust the air by moving the red cam to a lower number until a trace of smoke is achieved with CO2 level as high as possible (lowest possible O2).

Example: 13.5% CO2 (2.5% O2) with a trace of smoke.

b.Increase the air by increasing the red cam

number to reduce CO2 by 2 percentage points at a zero smoke level. (Increase O2 by 3 percentage points at a zero smoke level.)

Example: Reduce CO2 from 13.5% to 11.5%, with zero smoke (or increase O2 from 2.5% to 5.5%).

c.A margin of reserve air has been added to accommodate variable conditions.

7.Check the breech draft pressure against the appliance manufacturer’s recommended setting (typically + 0.1” W.C.).

8.If the breech pressure is higher or lower than recommended level, adjust the appliance breech damper to achieve the specified setting. Recheck the smoke and CO2 (or O2) levels. Adjust burner air if necessary.

9.Once all settings are complete and satisfactory, proceed to ‘Set Low-fire Air’ Section.

Set Low-fire Air

1.Move the low-fire hold switch from the high fire position to the low fire hold position.

a.The damper will return to the low-fireair setting.

2.Check the smoke and CO2 (O2) levels.

a.Pull a smoke sample from the flue.

b.The sample should be clean (zero smoke level).

c.Check the CO2 (O2) level:

d.CO2 should be at 11 to 12% (O2 at 5.9 to 4.5%).

e.If the CO2 is less than 11% (O2 more than 5.9%), decrease the air and check the smoke level.

3.Operate the burner from low fire to high fire and back to verify operation.

4.Turn the burner off. Wait one or two minutes (for chamber to clear) and then turn on again to verify starting characteristics.

5.Perform limit circuit performance test specified by appliance manufacturer to verify operation of burner/appliance combination.

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