Electronic Ignition systems:

a. Intermittent pilot with non-100% shut-off - When room thermostat calls for heat, pilot valve opens and pilot is spark ignited. Then when pilot is proven, main gas valve opens, when room thermostat is satisfied, main gas valve and pilot valve are de-energized.

b. Intermittent pilot with 100% shut-off - Same as non-100% shut-off except the system with lockout and require manual starting if the pilot fails to ignite in a given time period. Electronic ignition with propane must be 100% shut-off.

Room thermostats -Several models of 24 volt thermostats available.

Fan time delay relay - Used to energize system blower motor or controller.

Two-stage gas valve - Provides both 100% and 50% gas input to yield two firing rates. Two stage thermostat is a required extra. (Natural gas only). Electric igniting required. Not available on DU-50.

Modusnap gas Valve - For applications requiring only make-up air. Direct-acting non-electric valve modulation gas flow to provide constant leaving air temperature, with a modulation range of 100% down to 30% of rated input. Not available for DU-50.

"Selectra" modulation systems (Not available for DU-50)

MS-1: For applications requiring only make-up air. Maxitrol solid state electronic modulating system provides constant leaving air temperature. Wall mounted "Selectrastat" permits adjustment of discharge temperature from convenient location.

MS-2: For space heating only applications. Maxitrol solid state electronic modulating system provides continuous blower operation and extremely close control of space temperature.

MS-3: For make-up air and space heating applications. Same as MS-1, but with two-position Overriding room thermostat for space heating as well as make-up air.

Notes: "Selectra" systems modulate down to 30% of rated input. MS-1 and MS-3 require a minimum of 6 foot discharge duct for field mounting temperature sensor.

High fuel pressure regulators (field installed):

a. 1/2 to 5 lb. line pressure (specify gas pressure)

b. 6 lb. to 40 lb. lie pressure ( specify gas pressure)

Power venters - Are generally required with gas duct furnaces where:

1. Negative pressure exists inside the building
2. Flue pipes have downward or long horizontal runs
3. Heaters are vented directly through a side wall with no vertical stack
4. Heat exchangers or stacks are extremely cold and will not provide adequate draft on start-up.

Power venters and companion adapters are shipped for field installation.

Dual-Fuel manifold - Natural/LP gas kit includes dual-fuel manifold, spuds and LP gas controls. Pilot remains on natural gas except on units with electronic ignition systems. Available only for field installation.

Note: Dual-fuel manifold and power venters are not A.G.A. / C.G.A. design certified.

PERFORMANCE