Residential Oil Burner Controls and Fuel Pumps

Reprinted from WEIL-McLAIN Technical Service Bulletin 4/11/03

Residential Oil Burner Controls and Fuel Pumps Reprinted from WEIL-McLAIN Technical Service Bulletin 4/11/03 Weil-McLain utilizes the Beckett “Cleanout” oil pump and Honeywell R7184P Primary Control as standard equipment on Beckett burners used on Weil-McLain oil-fired boilers. This new oil pump differs from previously used oil pumps in that the new “Cleancut” pump has a built in oil solenoid, whereas previous pumps had a separate oil solenoid valve that attached externally to the pump. The “Cleancut” pump performs to all the same specifications as the Suntec “A2” single stage pump used previously. In addition, the oil solenoid coil and stem assembly can be replaced if required. If a two stage pump is required, a “Cleancut” model with the built in solenoid is not available and a separate oil solenoid should be installed with a normal two stage pump for those applications.

NOTE: The “Cleancut” pump requires the primary control have a valve “on-delay” (pre-purge) for proper pump operation. Failure to utilize a primary control with pre-purge will cause the burner to have a rough, smoky, light-off.

The Honeywell R7184P-1080 (interrupted control—transformer shuts down 10 seconds after flame is established) is now the standard control used on all Beckett oil burners along with the new “Cleancut” pump. The Honeywell control has both a 15 second pre-purge and a 15 second post purge feature, as well as internal self-checking of the control itself. The control has 15 second lockout timing plus a 10 second ignition carry over period. After 3 lockouts during the same call for heat, the control goes into restricted lockout., A restricted lockout condition may be reset by holding the reset button down for 30 seconds until the LED flashes twice. At any time the control is powered, the reset button may be held for 30 seconds to reset the lockout counter. There are several new “Service Features” with the R7184P control that make for easier servicing.

With an initial call for heat and the ignition on, when the reset button is quickly pressed and released, the lockout time will be extended to 4 minutes to allow time to purge air out of the oil line. After 4 minutes the control will lockout and must be reset.
Also, quickly pressing and releasing the reset button while the burner is firing will cause the LED to flash showing the cad cell resistance:

flash=cad cell resistance of 0-400 ohms,
flashes=cad cell resistance of 400-800 ohms,
flashes=cad cell resistance of 800-160 ohms,
flashes=cad cell resistance ³ 1600 ohms.

At any time during the oil burner operation, if the reset button is held down, the burner will remain off. When the reset button is released, the burner will return to standby and normal operation. Another important service note is that the Honeywell R7184P control wiring is slightly different than the Carlin 60200 control wiring. This becomes important when replacing a Carlin 60200 (or 50200) with a Honeywell R7184P control. On the Carlin 60200 the black wire is connected to the boiler limit circuit, whereas the red/white wire is connected to primary L1 power. On the Honeywell R7184P control, the red wire is connected to the limit circuit and the black wire is connected to primary L1 power. The other wire colors remain the same.
Also, the R7184P-1080 comes with a factory installed jumper (looks like a resistor) soldered above the T & T terminals on the R7184P. For use in a system with a low voltage thermostat that controls the oil burner primary control, this resistor must be cut out or the boiler will run continuously. The low voltage thermostat will then connect to T & T as normal. Typically steam boilers will have this resistor cut and water boilers will have a resistor intact (thermostat on water boilers typically connect to aquastat control).

A troubleshooting card comes with every burner and should be invaluable when working with the Honeywell Control.