Thermo Products omd-70 service manual K. Burner Installation

All installations and services must be performed by qualified service personnel.

K. BURNER INSTALLATION

The burner mounts to the furnace on three mounting bolt studs, located on the burner mounting plate, in the lower portion of the vestibule, directly in front of the heat exchanger.

The burner insertion depth has been fixed by the factory for the design-specified, combination of the air tube length and the combustion chamber used with the furnace. The combustion chamber is pre-positioned during the assembly process and held in place by the drum and mounting plate. The burner insertion depth is not field-adjustable.

Should access to the chamber be necessary, refer to the exploded diagram, in the back of this manual, to identify replacement parts.

To install and ready the burner for firing, follow the steps below for both furnace models.

1.With electrical power connected to the furnace, turn off all electrical power to unit.

2.Remove the front lower access panel.

3.Mount the burner to the furnace. Install the flange gasket over the mounting studs and secure the burner flange to the furnace using hex head machine screw nuts, provided in the Parts Kit.

4.Connect the red and white wires from the burner harness to the black, red and white burner power leads found underneath the primary control. Then connect the two yellow wires to the “T & T” terminals on the front of the primary control.

For the oil burner installation (OMD) only:

5.Determine whether an oil return line is required and connect the fuel oil piping to the burner oil pump through the base of the unit.

6.Turn on electrical power to the furnace. Cause or simulate a “call for heat” to bleed air from the oil line at the oil pump. (Temporarily, connect the two thermostat leads to cause the oil pump to run.)

7.With all oil shutoff valves open, open the air-bleed valve on the oil pump and capture the oil flow in a container until all traces of air in the line are gone.

8.Close the air-bleed valve. Check for and correct any oil leaks. The furnace is now ready for burner adjustment. Refer to the following “BURNER OPERATION AND ADJUSTMENT” section.

For the gas burner installation (GMD) only:

5.Connect the gas piping to the burner through the base of the unit.

6.With all gas shutoff valves open, bleed air from the gas line by opening the pipe union closest to the furnace a small amount. Carefully, close the pipe union when the odor of gas becomes strong. Check for and correct any subsequent gas leaks.

Wait five (5) minutes for any lingering gas to dissipate. 7. Turn on electrical power to the furnace.

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