No matter if your water heater is gas, electric, or tank type, here are some tips for troubleshooting it before it fails. One of the most frequent issues is a pilot light that either doesn’t illuminate your burners, or stays lit but doesn’t ignite them. This usually indicates an issue with either your thermocouple or gas control valve.


water heater repair how to

1. Check the Thermostat

The thermostat is essential in controlling the temperature of a water heater. It turns on upper and lower heating elements when necessary, then switches them off when not. A broken thermostat can have serious consequences for your system’s overall performance; so, it’s best to replace it as soon as possible.

A positive reading indicates your thermostat is functioning correctly. If not, then the thermostat may have developed an issue and needs replacing.

To test the thermostat, you’ll need a multimeter. This could either be an analog or digital model depending on which you have. Set the meter to its lowest resistance setting and adjust its scale accordingly. Place one probe on terminal screw #1 of the upper thermostat, followed by another one on terminal screw #2.

You can check the temperature with a thermometer. If it reads significantly higher than usual, this could indicate an issue with your thermostat.

Once you’ve verified the thermostat is functioning properly, you can remove both upper and lower panels to access it. These will typically be located on either side of the tank and should be covered in insulation. Fold this away temporarily with tape before proceeding.

Now that both thermostats are accessible, you can test them for continuity with a multimeter to identify which thermostat requires replacing.

2. Check the Temperature Sensor

The temperature sensor of a water heater is an integral component of its system for maintaining water’s temperature. It continuously monitors the water’s temperature and sends an indication to the thermostat when it reaches desired level. Without it, your heater won’t function correctly.

No matter the type of water heater you have – gas or electric – the temperature sensor is responsible for keeping it at an ideal temperature. Without it, your heater could produce too hot or too cold water depending on its configuration.

A malfunctioning sensor may indicate other issues, such as an unresponsive gas control valve or thermostat malfunction. In such cases, replacing the sensor may be necessary.

First, test the sensor’s connections using a multimeter to confirm they are secure.

Next, test the resistance of the sensor. If it falls within its manufacturer’s range, then it appears to be working correctly. However, if it exceeds this range, then you should replace the sensor.

You can do this by testing the sensor at different temperatures. Afterward, compare its resistance reading with that provided by your water heater’s manufacturer.

If the resistance of your sensor does not match what is listed on the chart, then it likely has a malfunction. In such case, replacing the temperature sensor should suffice; otherwise, repair either your gas control valve or thermostat to restore proper functionality to the sensor; alternatively, call in an expert for water heater repairs.

3. Check the Pressure

If your water pressure is low, it’s essential to identify and address the cause and take preventive action before things worsen. Professional plumbers can conduct routine inspections for signs of buildup, leaks, broken pipes and other plumbing issues that could reduce your hot water supply.

One of the most crucial components in your water heater is a pressure relief valve. This device releases hot water and steam until the pressure inside the tank has been restored.

Your model of tank may have a valve located above or high up on one side; to test it, open the drain line and read the pressure in your tank.

A pressure relief valve will occasionally release large amounts of water when your tank’s temperature or pressure exceeds a certain point. This prevents explosions caused by too much pressure in your water heater tank.

It’s wise to inspect your water heater’s pressure relief valve twice annually to make sure it works correctly. Doing this increases the likelihood of detecting an issue before it causes major harm or requires costly repairs.

You can check the pressure of your water heater by installing a pressure gauge on its drain line outlet. These are available from home improvement stores.

If your pressure gauge displays a very low reading, the issue could be with either your water heater itself or its heating elements. As metal expands when heated, it can create small fractures in the tank’s walls which allow water to seep out; these leaks usually seal themselves once the tank cools and the metal returns to its original shape.

4. Check the Element

If your water heater isn’t heating up as expected, a faulty element could be to blame. You can check this with either a multimeter or Ohmmeter.

First, turn off the power to your water heater at its main electrical panel. Then, remove the plastic safety cover over the heating elements. If yours doesn’t have one, take off both metal covers and insulation.

Once the heating elements have been exposed, use a continuity tester to check for current flow between the two metal parts of your water heater. If there is no current present, the element has likely failed and must be replaced.

Another common test for a defective heating element is using a non-contact voltage detector. This small tool, shaped like a pen with a point on the end, can be purchased at any hardware or home improvement store.

When you place the non-contact voltage detector on one of the wires running from the thermostat, it should beep or illuminate. If not, there is no power to your water heater and you must find a way to disconnect it before continuing with testing or replacing the element.

Finally, use either a multimeter or an Ohmmeter to check for resistance between the terminals on the upper heating element of your water heater. The reading should be close to zero ohms for efficient and effective heat regulation.

5. Check the Connections

Water heater connections to hot and cold water pipes should be secure and free from corrosion. If these connections are leaking, you may need to replace the heater altogether.

If your water heater uses natural gas or propane, make sure the pipe is insulated and there are no leaks at the connections. You may also check for galvanic corrosion – when copper and steel pipe threads come into contact and begin to corrode together.

Once you’ve checked the plumbing, be sure to connect the gas supply line to a shut-off valve. You may opt for using a flexible gas connector (instead of threaded piping), which makes installation simpler and is required in earthquake zones.

Before beginning this project, make sure the power to your home has been checked for power cuts or breakers. If the breaker has tripped, reset it.

Next, unscrew the cover plate to access the junction box located beneath a water heater or on its side. It should have two lead wires and a ground screw.

A 240-volt neon test light can be useful here, as it illuminates any bare wires that aren’t insulated. Be sure to carefully remove the wire nuts or tape from each connection without touching them; touching an uninsulated copper wire could potentially result in an electrical fire.

If you come across any exposed copper wires, take them out and secure them with wire nuts or black or red electrical tape. Be sure to connect the white circuit wire to either the green grounding screw on your water heater or its ground lead, whichever applies.

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