How to operate a gas control valve and thermostat on Whirlpool gas water heaters - step by step guide. Understanding diagnostic codes.
Whirlpool gas water heaters, such as those with the Flame Lock feature, utilize a gas control valve with the 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 the gas valve but with an addition of wires connected to a thermal switch. You can find two types of codes on the control valve; status indicator and diagnostic codes.
When there are 0 flashes and the led light is OFF, the pilot light is out because there is not enough power to keep it ON, or turned OFF.
1 Flash every three seconds means that the water heater is operating as it is supposed to.
Continuous flashes mean that the water heater is shutting down.
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 – Due to sensor failure, replace the gas valve.
7 Flashes – Due to 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.
The water temperature inside the water heater tank can be adjusted from 55 F to 155 F, while some models can produce hot 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. In contrast 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 an extended period. This is how a water heater is protected from freezing, with minimum energy losses.
The gas control valve and thermostat are 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. At the same time the diagnostic status light will flash four times (overheat failure).