RESIDENTIAL GAS, NON POWER VENTED, WATER HEATER
SERVICE HANDBOOK
Residential Gas – continued
Temperature: Two metal probes mounted onto the back of the control are immersed inside the tank water. One probe (the shorter) acts as a temperature high limit. If water gets excessively hot, a sensor within the probe opens, interrupts the small electrical current to the gas valve, and gas flow through the control is interrupted. If this safety sensor opens, the entire control must be replaced.
The longer probe contains a metal rod that expands and contracts as water temperature around the probe cools and heats. As the rod expands, it pushes against a lever actuated gas valve. If the regulator is pushed sufficiently, gas flow is interrupted to the main burner. Adjusting the temperature dial changes the distance the rod must expand or contract to open or close the gas valve.
Gas: When you prepare to light the pilot, you are instructed to turn the top
knob to the pilot position and depress the knob. When the knob is depressed gas will flow to the pilot burner only. You then have to (manually) ignite this pilot gas. When the pilot is lit, the flame must heat the thermocouple until it generates sufficient electricity to the gas valve to allow you to release the knob while gas continues to flow to the pilot. When the top knob is turned to the “ON” position, gas is also available to the main burner if the thermostat calls for heat.
State Water Heater | 8 | Technical Training Department |
© 2004 |
| Ashland city, TN |