Some common problems with water heater thermostats include the temperature being set too low, improper wiring or installation and a bad heating element, notes HomeAdditionPlus.com. Water heater thermostat problems range from simple fixes such as adjusting the temperature or relighting the pilot light to complicated and potentially dangerous issues such as an obstruction blocking the water heater flue.
In order to troubleshoot common water heater thermostat issues, address the most common and easily remedied issues first such as the settings and pilot light. First, check to make certain the circuit breaker has not tripped, the fuel valve to the water heater is on and the pilot light is lit. A pilot light that has gone out can be reignited, but in some cases, the igniter may need a replacement if the problem is a recurring one. If the pilot light is lit, the temperature may have been inadvertently adjusted. Readjust the temperature to see if the water temperature warms to the desired level.
If the pilot light and temperature settings are addressed but water thermostat issues continue, the problem may be due to an obstruction, faulty installation or heating element failure. These issues may require professional assistance, usually involving repair or replacement by a plumber.