Columbia L-24, Owner'S Manual, Page: 43 / 60

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PRIMARY CONTROL FUNCTION - SAFETY LOCKOUT
CAUTION: DO NOT RETRY IGNITION MANUALLY IF THE BURNER FAILS AND THE BOILER IS
HOT! FORCING A REFIRE AT THIS TIME CAN PUT FUEL INTO THE HOT COMBUSTION CHAMBER
AND CAUSE AN EXPLOSION HAZARD. THE CONTROL WILL AUTOMATICALLY ATTEMPT TO
RESTART AFTER 45-60 SECONDS IF THE CAD CELL DETECTS A FLAME INITIALLY. THE CON-
TROL WILL LOCK OUT THE BURNER AFTER 3 UNSUCCESSFUL RETRIES.
When the primary control locks out there is a malfunction. Determine the cause. The primary control is a safe-
ty device similar to a breaker in an electrical circuit. It will reset when:
1. The cad cell (electronic eye) detects a reduced, dirty or no flame for over 30 seconds. A signal
measured in ohms is communicated between the cad cell and the primary control. A poor or absent
flame produces a high ohm reading. When this signal is > 1500 ohms the control goes into reset. A
signal indicating a very good flame is < 500 ohms. A moderate flame would be 500 to 1000 ohms.
2. The cad cell has failed, lens is dirty, or retention head is dirty.
3. The retention head fins are not allowing light to pass to the cad cell.
4. The cad cell receptacle is not making good contact with the cell.
5. The primary control is defective allowing the reset button to pop too easily.
ROUTINE BURNER MAINTENANCE
Weekly Maintenance
A flame inspection mirror is useful for a routine check of the nozzle, ignition, and retention head while the unit
is operating.
1. Observe flame--adjust if needed.
2. Check all filters and water traps in the oil and air supply lines. Clean if needed.
3. Check barometric damper draft setting and be sure flap has freedom to move.
4. Inspect chimney integrity at elbows, tees, fire-stops, roof cap.
Be prepared to clean the heat exchanger and burner head area and nozzle every 500 to 1000 hours
A properly cleaned & maintained boiler operates efficiently and prevents possible soot fires. A clean
flame and good draft will allow longer intervals between cleanings.
Scoop or vacuum ash from the firebox and brush between the water tubes. Remove stack sections as
needed to get ash from inside of chimney. Horizontal runs will collect ash and create draft problems if
not cleaned regularly.