Theory Of Operation - Master TENTEvent125 TB116A Owner's Manual

The Fuel System: The hose/regulator assembly attaches to the propane gas supply. The
propane gas moves through the automatic control valve and out the injector.
The Air System: The motor turns the fan. The fan pulls air into and around the combustion
chamber. This air is heated and provides a stream of clean, hot air.
The Ignition System: The direct spark ignitor (DSI) sends voltage to the spark ignitor. The
spark ignitor ignites the fuel and air mixture.
The Safety Control System: There are 4 independent systems:
1. Flame Sensor: This system causes the heater to shut down if the flame goes out.
2. Thermal Switch: This system causes the heater to shut down if the heater gets too hot
(blocked openings).
3. Air Pressure Switch: The system will not allow the heater to start if there is not adequate
air flow.
4. ODS - Oxygen Depletion System: This system shuts down the heater if the oxygen level
drops below the specified level (18%).
ODS Operation: Burner porting "blows" out causing flame sensor to cool, shutting down heater.
Cool
Air In
(Back)
DSI
Power Cord
Thermal Switch
Hose/Regulator
Assembly
Ignitor, Flame
Sensor and ODS
8

THeory oF oPeraTion

Fuel
Figure 2 - Cross Section Operational View
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Air for Fuel
System
Motor and
Blower
Assembly
Air Pressure Switch
Clean
Heated
Air Out
(Front)
Combustion Chamber
Burner
Injector
120942-01E