OIL FIRED FLOOR FURNACE

Unique, high capacity furnace mounts directly in floor of living space to provide safe, efficient heat without the need to run ductwork. Ideal for single story home homes built on crawl space, vacation cabins and cottages, or as a modern upgrade for obsolete gravity furnaces. Burner and blower assembly are completely serviceable from top of unit, eliminating the need to enter crawl space after installation. Large blower of the same type used in conventional furnaces helps reduce register temperatures while moving large volumes of heated air. Standard equipment includes flame retention oil burner, heavy gauge steel heat exchanger, cad cell type primary control and fan/limit control. Electrical supply: 115v AC.

OFB-100 105,000 .75 gph 24 x 36 x 32” 24 x 36” 6” WITH AN ADDITIONAL

OFB-100 Series

PRORATED ON HEAT EXCHANGER

CAT. NO. MFG. NO. BTUH OUTPUT FIRING RATE DIMENSIONS WXLXD FLOOR OPENING FLUE WEIGHT EACH 1H045

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$3,042.73

SAFETY SWITCH TRIP OUT ON OIL BURNERS

Sometimes after all of the obvious causes for safety switch trip out have been checked, the switch continues to trip out at the most inopportune times. The flame pattern is correct, the nozzle sizing is correct, the pump pressure is correct; we have “good” draft, both over fire and at the stack, “good” readings on the combustion test, and “good” stack temperatures. The cad cell assy has been replaced and the primary control has been replaced. Even the possibility of a slipping coupling has been checked. Still… the burner trips out on safety sometime during the day/night, following the service call. Normal electro-mechanical problems have been checked, but have the following been checked?

Is the burner being supplied with clean oil?

Disconnect the supply line at the tank and drain some oil into a clear container. Let it set in the container for 15 minutes. Examine the oil for any separation, suspension, or discoloration. Discoloration, suspension, and separation, are caused by par- ticulates, algae, unknown mixes of chemicals, and moisture. A single drop of one of these contaminates in the nozzle line can cause a miss fire and a resulting safety trip out.

Is the oil supply system “tight”?

While the line is disconnected at the tank, remove the line at the burner connection. Plug either end and connect to the other end with your push-pull hand pump and draw a 10” vacuum on the line. Does it hold the vacuum for 5 minutes? If not, there is a suction air leak in the line. Air drawn into the pump can cause flame pulsation, or flame out, resulting in a safety trip out.

Is there excessive vacuum at the suction inlet connection to the pump?

Measure the vacuum at the pump inlet. Vacuum readings should not exceed 8”. We know oil pumps are rated for higher vacu- um, but that is when they are new, when the strainers in the pump are clean, when the gears are new, and the cutoff is tight, and the oil filter(s) is clean. Over extended periods of operation @ 10” of vacuum, air will be cracked out of the oil at the pump. As the air accumulates in the pump, it will displace enough oil to cause a flame out, along with the resulting safety trip.

Is there a chamber after-burn?

As burner components wear, the possibility of the burner motor continuing to spin for a few seconds after power is shut off increases. The burner pump is “broken in”, the motor bearings are looser; the fan is carrying more centrifugal weight (dirt). The flue passages have accumulated some soot. The restricted flue passages do not allow the chamber heat to dissipate as quickly, which keeps the chamber “glowing” longer. (Obvious evidence of the above would be a coke build-up below the tube assem- bly, severely discolored nozzles, even warped burner heads.) These factors can cause an after-burn, which may last for a few minutes. Should the burner experience a call for heat during the after burn, the controls will sense an existing flame, which may result in a safety trip out. More often than not, one or more of the above is determined to be the cause and the mystery trip out problem is solved.

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AIR CONDITIONING & HEATING EQUIPMENT