When a customer calls you about a problem with their electric water heater, you know it’s potentially urgent. Electric water heater problems can cause a variety of symptoms, including issues with water temperature, leaks, discoloration, odor and noise. Here’s a guide to troubleshooting electric water heaters in order to figure out the root cause of the problem.
Before You Start: Turn off the Power
For safety, before you start doing any troubleshooting for an electric water heater, make sure you turn off the power. You can do this by turning off the fuse or circuit breaker connected to the heater unit.
Water Temperature Problems
Several types of electric water heater issues can cause problems with water temperature. Symptoms can range from no hot water to inadequate hot water to water that’s too hot.
When there’s no hot water, the problem can stem from lack of power, a faulty electric thermostat or a faulty upper electric heating element. Start by ruling out power problems. First, reset any tripped circuit breaker, and replace any blown fuse. Next, check if power is being supplied to the electric water heating element thermostat. Test the element, and if it’s faulty, replace it. Finally, if the thermostat is receiving power but is still not working, replace it or the electric water heating element.
When the water’s not hot enough, the problem can be an undersized water heater, crossed hot and cold connections, or a faulty heating element or thermostat. To rule out an undersized heater, check to make sure the heater has 75 percent of its capacity as hot water. Next, rule out a crossed connection by turning off the water supply and turning on a hot water faucet; if the water still flows, look for a crossed connection. After this, check the lower and upper heating elements for power and electrical continuity and replace the element if necessary, being sure to clear any sediment first. Finally, if the elements are working, check the upper thermostat first and then the lower one and replace if either is not working.
When water is running too hot, it usually means the thermostat is set too high. Check to make sure the upper and lower thermostats are set between 110 and 140 degrees Fahrenheit.
Water leaks can be caused by a faulty temperature and pressure (T&P) relief valve, excessive pressure, overheating, a stuck valve, a leak from an overhead or adjacent plumbing connection, loose heating element bolts, a bad gasket or a leaking water tank. To check the T&P valve, place a bucket under the overhead pipe, open the valve and flush it clear of debris; if it still leaks, repair or replace it. Next, to reduce excessive pressure or heat, lower the thermostat setting. After this, check for loose pipe connections, and use a wrench to tighten any you find, being careful not to over-tighten. Next, check the heating element bolts, tightening them if needed. If the heating element is still leaking, remove it and replace the gasket. Finally, check if the storage tank is leaking. Storage tanks can leak due to corrosion or other issues such as bad o-rings. Keep some extra o-rings handy from a supplier such as Apple Rubber in case you need to replace an o-ring.
Discoloration or Odor
Rust-colored water can be caused by corrosion inside a glass-lined tank or a failing sacrificial anode rod. If the anode rod is failing, replace it with a magnesium anode rod.
A decaying sacrificial anode rod can also release hydrogen, causing a smell like rotten eggs. To address this, first flush the water heater. Then treat the tank and pipes for two hours with a solution of 2 pints of 3 percent hydrogen peroxide to 40 gallons of water. If the smell persists, replace the failing anode with a zinc-alloy anode. If the smell still doesn’t go away, replace the heater with a plastic-lined one.
A low, rumbling noise can indicate boiling water, caused by overheating due to sediment build-up. Treat this by flushing the water heater.
A high-pitched, whining noise can be caused by build-up of scales on electrical heating elements. To treat this, first flush the water heater. Then clean the scales from the water heater tank and elements. Finally, install low-watt-density heating elements with a larger surface area for greater heat-transfer efficiency.