PROPER BURNER FLAME
A proper flame will have a dark blue inner mantle that sits right on top of the burners with a lighter blue outer mantle rising above the burner, (See Figure 11). There may be some yellow where the pilot flame and burner flame meet. There is no primary air adjustment on the burner, and proper flame is assured since the correct manifold pressure and orificing has been done at the factory. NOTE: It is advised that the burner flames be checked at least twice during the heating season for any changes in burner flame characteristics. The appliance area must be kept clear and free from combustible materials, gasoline, and other flammable vapors and liquids. This heater comes from the factory with the proper burner orifice for elevations up to 2,000 feet. Heaters installed above 2,000 feet must be derated 4% for every 1,000 feet. For the proper orifice size find the Model Number and elevation on the orifice chart (See CONTROLS). Replace burner orifice.
5” to 7”
Approx. 1 ”
FIGURE11
OPERATION
This unit uses a “step open” valve. When heat is called for the gas valve opens at a reduced manifold (outlet) pressure to insure a safe, quiet ignition. After 10 – 20 seconds the valve automatically steps up to normal manifold outlet pressure to provide proper BTU input for the remainder of the heat cycle.
After the heat exchanger has warmed sufficiently, the fan will automatically come on to efficiently transfer the heat into the room. NOTE: All but the 35,000 BTU unit (which is one speed) have an automatic
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