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Water Heating Not Working? Troubleshooting a Faulty Water Heater

A malfunctioning water heater can present a range of problems, from inconvenience for a single-family homeowner to a catastrophe for the landlord or manager of a large residential property. Here are some tips for troubleshooting a faulty water heater from the pros at Calray Boilers, your “hyper-local” blue-chip boiler and heating brand for nearly a century.

Water Heaters vs. Boilers

What’s the difference?

Before we get into the specifics of troubleshooting a faulty water heater, let’s do a quick refresher about the difference between water heaters and boilers. A water heater is solely for hot water emanating from taps. A boiler may be used for both hot water and to provide steam heat via radiators. We address boilers in other posts. In this article, we are concentrating on water heaters.

Common Water Heater Problems

No hot water

Waking up on a cold winter day to no hot water for a shower is a sure way to ruin the morning. The first thing to evaluate if this happens, after double-checking the thermostat knob, is the power source, which may be gas or electricity. You may have a combination of both if you have a gas heater with an electric ignition.

Make sure your circuit breaker hasn’t tripped. If it has, turn it back on. If the breaker keeps tripping, you will need to have a licensed electrician check the wiring and panel. It’s possible you have a short that is causing the breaker to trip as a safety mechanism. The water heater may also need to have its own breaker, and the power supply needs to be sufficient for a large appliance.

If you have a gas-fueled heater, make sure the gas supply is on and the burner is lit. See the section below for more hints about dealing with malfunctioning pilot lights and burners.

If power and fuel have been ruled out as the cause of your problem, it’s likely your heating element is the culprit. With electric water heaters, the tubular element, which resembles the heating unit inside an electric stove, may have corroded and snapped off. Or, it could be buried in sediment at the bottom of the tank if you have hard water.

Gas heaters have a chimney running through the middle of the tank rather than a heating element. This could be broken, causing safety features to shut off the heater. Unless you are particularly handy, issues with the heating element and chimney should be treated by a professional, as they involve draining the tank and replacing parts.

Tepid water

If your water is tepid, it’s usually due to two issues:

• The thermostat is turned too low
• The heater tank is not big enough for demand

The first cause is easily remedied; the second one requires replacing the tank with a larger one, which should be done by a professional. It is also possible that the thermostat is faulty and requires replacement.

Occasionally, tepid water can be caused by a heating element or other part of a heater that’s going bad, so if the problem worsens until you have no warm water at all, you have your answer.

Water too hot

Likewise, water that is too hot has two common causes, one which you can fix yourself and the other that must be done by experts:

• The thermostat is turned too high (simply lower the temperature)
• A faulty pressure valve (it doesn’t turn the tank off when the water gets too hot and must be replaced immediately)

Pro tip: if getting just the right temperature water for your shower continues to be challenging, consider installing a pressure-balance or thermostatic valve for greater precision.

Discolored or malodorous water

A lot of our clients say their water is brownish, rusty, or smells bad. There are multiple possible reasons for this, each of which should be examined and fixed accordingly:

• Corrosion of the water tank, resulting in rusty water (replace the tank)
• Failure of the anode rod (flush tank and replace)
• Presence of bacteria (flush and clean with bleach or boil the water)
• Buildup of sediment on the bottom (flush and clean to remove sediment)

Noisy heater

If you hear banging, popping, sizzling, or other unusual noises coming from your water heater, you definitely have a problem. Usually, this is caused by too much sediment at the bottom of the tank – the result of hard water mineral scale – and the heating element is fighting to keep up. Draining and descaling the tank sometimes works, but if the buildup is really bad, you may have to replace the tank completely.

Leaking water

Never ignore water leaking from your water heater, as it’s always a sign something is wrong and likely to get worse. If you’ve checked and tightened all the connections, it’s probably caused by:

• Valve needing replacement
• Tank corrosion (replace the tank)
• Bad gasket (replace)
• Faulty relief valve (replace)

Pilot light or burner not working

Older water heaters still use a standing pilot light, although newer models have moved away from that system. Malfunctioning pilots or burners may be due to several causes:

• Problem with gas supply
• Broken gas valve
• Blockage in pilot light orifice or tube
• Thermocouple (flame sensor that controls gas flow) needs replacement
• Carbon buildup around burner (flame will glow yellow, not blue)

As with many of the solutions posted here, if you’re mechanically inclined, you may be able to do the repairs yourself, but if you need help, we’re happy to come out and do the job for you.

Pressure relief valve going off

Most water heaters have a temperature and pressure relief valve at the top. This is a safety feature to allow excess pressure and steam to escape and prevent an explosion. Never cover the relief valve when insulating a water heater. It’s vital to call a professional if your relief valve goes off repeatedly. Shut off the heater until it’s been fixed and is safe to operate again.

If you have experienced any of the problems above and find yourself stuck when it comes to a repair, feel free to call Calray Boilers at 212-722-5506, or use our easy online form to schedule an appointment. We are also available 24/7 for emergency calls.