Burnham V8 Series manual Jumper must be removed after this check

•Perform cad cell resistance check as outlined in control feature. If resistance is below 1600 OHMS and burner runs beyond safety cut-out time, cad cell is good.

•If safety switch shuts down burner and resistance is above 1600 OHMS, open line switch to boiler. Access cad cell under ignitor, clean face of cad cell and see that cell is securely in socket. Check gasket around perimeter of ignitor lid for proper seal. If gasket is missing or damaged, replace gasket. Room light can effect cad cell resistance. Reset safety switch.

•Close line switch to boiler. If burner starts and runs beyond safety switch cut-off time, cell is good. If not, install new cell.

v.Power Failure Check: After Flame is established, turn the power off to the control/ burner. The burner should shut down safely. When power is restored a normal ignition sequence should be started.

3.WARNING — Check High Limit Control

—Jumper Thermostat Terminals. Allow burner to operate until shut-down by limit. Installation is not considered complete until this check has been made.

WARNING

Jumper must be removed after this check.

4.Check low water cut off control with water level at normal water line (see Figure 1D). Raise thermostat setting to allow burner to operate. Open boiler drain to allow water level to drop to bottom of sight glass until burner operation is shut-down by low water cut-off.

Close boiler drain and refill to normal water line. Burner should automatically restart during fill. Lower thermostat setting.

5.Check operating control on boiler equipped with tankless heaters. With burner off, draw hot water until burner starts, then turn off hot water and check burner shut-down.

J.IF CONTROLS DO NOT MEET REQUIREMENTS outlined in Paragraph I., replace control and repeat checkout procedures.

AQUASTAT SWITCHING ACTION WITHIN L8124C CONTROL

The switching action within the L8124C control has three settings:

1.high limit

2.low limit

3. adjustable differential

HIGH LIMIT OPERATION —

The high limit opens and turns off the burner when the water temperature reaches the set point. The high limit automatically resets after the water temperature drops past the set point and through the 10°F differential.

Set the indicator at desired shut-off temperature.

LOW LIMIT OPERATION —

On a temperature rise, with the adjustable differential at the minimum setting of 10°F, the burner circuit (R-B) breaks and the circulator circuit (R-W) makes at the low limit set point. On a temperature drop of 10°F below the set point, the R-B circuit makes and the R-W circuit breaks.

ADJUSTABLE DIFFERENTIAL —

At any differential setting greater than 10°F, the R-B make temperature and R-W break temperature will remain the same-control setting minus 10°F. The R-B break and R-W make temperature will be the set point temperature plus the difference between the differential setting and 10°F.

EXAMPLE: Set point of 140°F; differential set at 25°F. On a temperature rise, R-B will break and R-W will make at 155°F. On a temperature fall, R-B will make and R-W will break at 130°F.

Set low limit indicator at the minimum temperature recommended for domestic hot water supply. This setting must be at least 20°F below high limit setting to prevent one switch from locking out the other.

Set the differential the desired number of degrees. 25°F differential gives longest burner cycles.

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