How to Operate Gas Valve and Thermostat on Whirlpool

Step by step guide, how to operate gas control valve and thermostat on Whirlpool gas water heaters. Understanding diagnostic codes.


Whirlpool gas water heaters, such as those models with the Flame Lock feature, use the gas control valve with thermostat to adjust the temperature of hot water and indicate when there is a problem with some of the heater’s elements. The assembly is the same as gas valve but with the addition of the wires that are connected to a thermal switch. There are two types of codes you can find on the control valve; status indicator and diagnostic codes.

Understanding the Status Light Codes

0 Flashes and led light is OFF indicates that the pilot light is out because there is not enough power to keep it ON, or it is turned OFF.

1 Flash every three seconds means that water heater is operating as it supposed to.

Continuous flashes mean that the water heater is shutting down.

Understanding Diagnostic Flashes

2 Flashes – Thermopile voltage is low. Before replacing the thermopile, check the wire connections first.

4 Flashes – Overheat failure followed by the tripped ECO requires you to replace the gas control valve/thermostat.

5 Flashes – Sensor failure, replace the gas valve.

7 Flashes – Gas control valve failure, replace the gas valve.

8 Flashes – thermopile is still producing the electric power even with the gas valve turned OFF. You might have to replace the gas control valve as the pilot valve is stuck open. Before that and when the pilot is OFF, you might want to wait at least 10 min for the thermopile to cool down and then try to relight the pilot.


How to adjust temperature of hot water

The water temperature inside the water heater tank can be adjusted from 55 F to 155 F, while some models can produce how water up to 180 F. The temperature dial shows only three settings: low, hot and very hot, and allows you to put your water heater in standard or vacation mode.

Standard mode allows you to set the temperature from its minimum to its maximum, while vacation mode lets you set the temperature to approximately 55 F, and is recommended when you are away and not using the water heater for extended period of time. This is how water heater is protected from freezing, with the minimum energy losses.

The gas control valve and thermostat is equipped with the Energy Cut Off (ECO) sensor that is a safety feature and it shuts off the heater if water temperature exceeds 189 F, while the diagnostic status light will flash four times (overheat failure).

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