Thermo Products CMA1-50N, CMA2-75N service manual F.Furnace Checkout Procedure

Models: CMA1-50N CMA2-75N

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

control, with one of the higher speed blower leads attached to a terminal marked “Park”. Be sure to attach any unused blower leads to a terminal marked “Park”. Replace the blower door and turn on the power supply.

F.FURNACE CHECKOUT PROCEDURE

Before any system of gas piping is finally put into service, it shall be carefully tested to assure that it is gas tight as indicated in the Fuel Piping Section of this Furnace Manual.

NOTICE: All controls on the unit should be checked for proper functioning prior to the qualified service personnel leaving the job site. Specifically the following should be checked:

With furnace in normal heating operation, check to make certain blower will start and stop automatically under control of integrated fan control.

1.Check safety limit control as follows:

a.Shut off incoming power.

b.Block return air opening or disconnect blower motor leads.

c.Restore power to furnace.

d.Set thermostat above room temperature calling for heat.

e.When temperatures are reached in furnace at limit control setting with blower out of operation, burner should shut off.

f.Shut off electrical power.

IMPORTANT: Remove blockage or reconnect blower motor and restore power.

2.Make certain thermostat will automatically start and stop furnace.

3.Block the flue pipe outlet gradually with a flat piece of metal, until the pressure switch functions shutting off the main burners. IMPORTANT: Remove flue outlet blockage when done.

4.Block the PVC pipe inlet gradually with a flat piece of metal until pressure switch functions shutting off the main burners. IMPORTANT: Remove air inlet blockage when done.

5.Remove the blower compartment access door with the furnace operating. The door interrupt switch is in the 120 volt circuit and will shut down the entire system. Replace the blower door and the furnace start-up cycle will begin.

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Thermo Products CMA1-50N, CMA2-75N service manual F.Furnace Checkout Procedure