Water Heater Leaking Repair and Troubleshooting Guide

If you have problems with your hot water heater leaking or it has stopped working,  you will find useful information  here enabling you to troubleshoot and repair the problem. Many problems are relatively easy to fix, some more complicated, you should only attempt a repair if you are confident in your ability to do so safely, if not you should call a qualified repairman. You can expect to pay around $100 to $150 for a simple repair, if the repair is complicated or needs expensive replacement parts the cost could be several hundred dollars or more.

water heater diagram

Emergency shut down

If water is gushing from either the tank itself or associated pipes then you need to immediately shut off the cold water supply feed. Before shutting off the water you MUST switch off the heaters gas or electric supply.

To switch off the gas supply – locate the flexible gas supply pipe, follow the pipe to the gas shut off valve and turn the lever a quarter of a turn.

To switch off the electricity supply – locate the cable supplying the heater and follow it back until you see a switch or circuit breaker, switch off the electric supply.

To shut off the cold water supply – The cold water feed is usually located at the top of the tank, locate the cold water pipe and follow it until you come to a gate valve, turn the valve’s handle fully clockwise. If there is no gate valve then the whole house water system will have to be drained and that procedure is beyond the scope of this article.

Locating the source of the leak

If the leak is just an occasional drip then there is no need to shut down the heater, however you do need to find the source before it becomes a major problem.

If you have a pool of water under your  heater this does not necessarily mean it is leaking , a common problem with water heaters is condensation, this occurs when large amounts of cold water fill the tank, for instance after someone has run a bath, condensation forms on the outside of the tank, runs down the outside and forms a pool of water. This is particularly noticeable in the winter when the incoming water is very cold, if the problem disappears in the warmer months then this indicates a condensation problem. The only solution  is to cover the tank with a  tank jacket, these provide a layer of insulation which prevents condensation forming on the outside of the tank .

Possible sources of the leaks are;

The temperature pressure relief valve – The valve is located on top of the heater, water seeping from this valve is not a leak as such, the valve is simply doing its job, which is to release water when excess pressure is detected. Excess pressure can be caused by the thermostat temperature being set too high, a faulty thermostat or the main water supply pressure to your home being very high. The valve itself may also be fault, if you determine that this is the source of the leak it is advisable to consult a qualified repair person as too much pressure could cause the tank to explode. Please see replacing a pressure relief valve

Pipes – If water is dripping from the pipes, then use a wrench to tighten the fitting that is leaking, dry the fitting and the area below and check back later to see if you have stopped the leak, if not you will need to replace the fitting.

Drain valve – The drain valve is located at the bottom of the heater, first ensure the valve is fully closed by turning the handle fully clockwise, if it does not have a handle and is the plastic type, take hold of the fixture and turn it fully clockwise. If after doing this the valve is still leaking, it is faulty and will need to be replaced. Please see replacing a drain valve

Electric heating element gasket – If water is seeping from the heating element, the gasket needs to be replaced, this is not a simple job and requires special tools, therefore  it is advisable to seek the help of a qualified repair person.

Tank – Hot water tanks have a limited life expectancy, usually around 10 years, leaks can spring from anywhere and the cause is usually rust or corrosion. When the leak starts it will usually be small but after time will gradually become worse, so as soon as it is noticed you should arrange for a replacement to be fitted as soon as possible.