Common water heater problems and how to fix them (2023)


With the advancement of technology, more attention is paid to the development of energy-efficient water heaters, so that consumers face less problems with water heaters and also less harmful impact on the environment. Water heaters heat the water when the tap is turned on. When the tap is turned on, water flows through the pipes and the heating coil runs on either gas or electricity and heats the water. The water is heated as needed, so no heat is lost. Problems can arise in any device if the connections are not made correctly.

In this article, we will take a detailed look at the most common problems faced by electric and gas water heater owners and how to solve them. Gas vs. electric instantaneous water heaters is a common discussion. Both have their advantages and disadvantages. Here we will look for some common problems that you may face with both types of units.

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Let's discuss the most common problems that users face with their water heaters. We will go through the problems of electric and gas water heaters.

Problems with electric instantaneous water heaters

Have you ever stepped into the shower for a hot bath and gotten cold water splashes instead? This happens due to a problem with your water heater. What could be causing this problem? The answer is a long list, which we'll look at next. The first troubleshooting step is to open the device and check for errors in it. Don't forget to disconnect the power supply to the device beforehand. Forgetting can have serious consequences. Now let's go through all the possible problems that could affect your hot water supply.

No hot water supply

Sometimes the water heater may not work at all, leaving you with only cold water from all the taps. This total lack of hot water can be caused by a clogged heat exchanger due to hard water supply. This clogging is avoided by regular flushing. A blockage of the ventilation leads to the shutdown of the system and thus to no hot water supply. For gas, instantaneous water heaters ensure your water heater is getting the right amount of electricity. When supplies become scarce, problems arise with water heating. A dirty burner or a bad igniter both cause the heating process to stop.

This problem can be solved by reducing water consumption. Try to limit yourself to using one faucet at a time. If this solves the problem, it means the problem is with the demand and not the unit. And if you want a device that can handle the increased demand, then buy one with a higher flow rate.

If you only use one faucet at a time and this problem persists, make sure the gas supply is uninterrupted when the unit is running on gas. Check that the vent pipes are not clogged. Check that the gas valve is on and not off. Try to maintain the device regularly. This avoids many problems and helps the device function optimally for longer.

Insufficient hot water supply

The hot water supply is not enough for all household chores. This problem occurs when you have bought a smaller device that cannot meet your needs. Try to buy units based on family needs so you always have plenty of hot water available. Tankless water heaters heat water on demand, so don't worry. Since there is no reserve in a tankless water heater, it takes longer to heat up the water than with a regular water heater. You may find this long wait frustrating at first, but you will get used to it over time.


If your water needs are 35 gallons, buy a 45 gallon capacity unit. Even when water demand exceeds capacity, you should take steps to limit consumption. Reduce the length of your showers. Install lower showerheads and try to perform water-consuming activities at different times of the day to avoid overloading your water heating unit.

If the water supply has suddenly dropped from normal, your heating element is definitely out of order.

Too hot water supply

Water temperatures above normal can damage the skin. The skin will burn if the water temperature is not right. This situation can be frustrating for the user and occurs due to a fault in the thermostat. High temperature means the thermostat is set too high. You can adjust it back to normal yourself without help. Sometimes the problem is with the thermostat sensors. You have resolved. Adjust the thermostat and clean the shower head, if that fixes the problem then the problem was with the thermostat setting. If the problem persists, look for sensors.


Turn off the power to your water heater. Expose the heating elements. Look for the thermostat temperature setting on both thermostats. Make sure it is within the normal range. The recommended limit is between 110 and 125 degrees. Take a tool like a flat head screwdriver to set the temperature to the desired limit. Bring the other thermostat to the same setting. Replace the insulation and plastic protection and reconnect the power supply. Wait some time and the hot water supply will be operational.

Why does my electric instantaneous water heater keep turning off?

A water heater that turns itself off every now and then will certainly be very annoying. What is causing this problem may not be a simple cause. We will list the most common ones here.

  • A loose wire can certainly cause this problem. If you suspect a problem with the wire connections, contact a plumber so they can fix it in no time.
  • Make sure your heater has the right supply of water, gas and electricity.
  • Check your water heater's filter to look for trapped debris.
  • Pay attention to the correct water flow rate. Non-instantaneous water heaters have a minimum water flow rate requirement, and if the requirement is not met, the heater will not turn on.


Valves and connections can leak. Reasons can be varied. Leaking water causes damage to the device and is a danger to the whole house. Sometimes water leakage is caused by loose connections. If this is the source of the problem in your case, tighten the connections. Other times this happens due to corroded pipes. The corrosion of the pipes is caused by mineral deposits. The mineral buildup corrodes the pipes and creates holes that cause leaks. The solution to this is to replace the corroded tube. Corrosion can be prevented by cleaning the device more frequently. If you have a hot water supply, installing a water softener also reduces the chance of damage to the system.


After prolonged use, the tubes can corrode, allowing water to leak from them. Check that your connections are tight and tight. If you feel they have become loose, use a wrench to tighten them. If your pipes are corroded, replace them with new ones as they cannot be repaired. To do this, first close the water supply valve, and then swap the pipes.

Rusty smelly water

The water that comes out of your taps should be clean and odorless. But if you see a tint, that's a sign your pipes are rusting. Smelly water indicates the growth of bacteria and is therefore a sign that the anode rod needs to be replaced immediately. This repair requires professional help.

Loud water heating

Does your water heater make unpleasant noises when heating the water? It is certainly due to the accumulation of sediment in your tank. The sediment deposits must be removed. First empty the tank and then clean it. To avoid mineral build-up in your water heater, perform monthly maintenance. Mineral deposits, if not removed in time, can cause irreparable damage to your device. This damage can result in the damaged parts having to be replaced. A guarantee does not make sense in this case either, since it indicates your negligence.

Cold water sandwich

This is a fairly common and irritating problem that all water heaters face. That is, when you turn on the faucet, the water supply is first hot, then gets cold, and then hot again, then hot again. The best solution to this is to install an air recirculation system. This directs the water back to the heater. One solution is to replace your water heater as this problem is more common with the old water heaters.

exhaust problems

Tankless instantaneous water heaters have an LCD display that displays error codes if there is a problem with your water heater. The code explains the cause and possible solution to the problem. If your exhaust is blocked, the display panel will show an error code that will provide information about the problem. This means the device has a problem with venting. First check all pipes for holes. Make sure you installed the device according to the guidelines. If the water heater is installed too close to other equipment, it will block the airflow and create a fire hazard. Vents outside the home may be blocked by bird nests to ensure all vents are clear and operational.

Also read:

  • What size water heater to replace 50 gallons
  • Best water heater for large families
  • Should I turn off the water heater when the water is off?

Problems with gas instantaneous water heaters

ignition failure

Can't light the water heater? This may be due to an empty propane tank. Make sure the gas supply is sufficient for use. If the gas valve is not fully open, the heating element will receive less gas than it needs. This will heat the water less efficiently. Open the valve fully. If this doesn't solve the problem, the problem is larger and requires professional help.

Flame failure

This can happen when either the gas supply or the electrical power source is not working properly. First make sure thatPropaneTank is still full. This problem can occur if the gas line is too short or there is a problem with combustion or vent lines. If you cannot understand the problem, contact a professional to ensure that the device is repaired in its best form.

Why does my gas instantaneous water heater keep switching off?

Just like the electric ones, if the gas instantaneous water heater switches off again and again, then there are several reasons.

Defective gas valve

If the gas valve shuts off the gas supply, the water heater will not ignite and the water will not heat up. Ask the installer to either repair the gas valve or, if the damage is beyond repair, to replace the old valve with a new one.

mineral composition

In order to decalcify the mineral deposits, the instantaneous water heaters must be flushed frequently. These mineral deposits can accumulate over time and destroy the heating element. Mineral deposits can cause the device to switch off suddenly. In addition, these mineral deposits can completely destroy the heating element. Installing a water softener reduces the need for frequent flushing. If you have a hard water supply, try to flush at least once a year to protect your expensive equipment from damage. The instantaneous water heater can last a very long time with proper care. Some studies suggest that a water heater can work well for up to 20 years. If a water heater is not routinely flushed and minerals build up inside the unit, it will cause the pipes to leak and therefore need to be replaced.

Improper installation

Installing a water heater all by yourself may not be an easy task. If you want to do this, go through the manual to get an idea of ​​where to place the different pieces. It can happen that a problem at the time of installation causes the device to corrode later. One such example is the use of dielectric joints to join the tubes. The dielectric joints are used when joining two different types of pipes. If they are used for the same tubes, the dielectric joints will cause the tubes to corrode. In instantaneous water heaters, brass fittings are used to make connections.

  • If the water heater temperature is set too low, it can also cause the unit to shut down.
  • Using a water-saving showerhead could be the cause of this problem.
  • Damage to the water flow sensor will cause the unit to shut down.
  • Vent pipes should be of reasonable length and not too short.
  • Gas pressure must be maintained at a certain level for the heating system to function properly.

Low water flow

Less water pressure makes it difficult to complete simple daily tasks. If your water heater's water pressure is too low, only use one faucet at a time. Make sure that multiple water-consuming applications are not used at the same time.

Check your water supply to make sure the problem isn't with your incoming water supply.

When the gas pressure is low, the device will automatically reduce the water pressure to keep the temperature stable.

The plumber should ensure that there are no problems with the water connections. All fittings and lines work perfectly.

Why does the instantaneous water heater switch off when taking a shower?

If you have a very old instantaneous water heater, it will certainly have a low minimum flow rate. The flow rate is the amount of water that must flow through the pipe for the heater to heat the water. If your water demand is below the unit's lower flow rate unit, it will shut off as part of a safety precaution. If the heat exchanger is not supplied with enough cold water, it can overheat and become damaged. In order to avoid this enormous loss, the device switches off. To solve this problem, ask your technician if you can update your device. The newest unit has a more suitable low flow rate. The lowest water flow rate ensures that the device runs perfectly even when you only need very little water.

Tankless water heaters are often preferred to traditional units as they are more energy efficient and require little maintenance. Like all other units, they are not immune to problems. In this article, we have listed some common problems with their solution.

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With years of experience, Adam decided to put his water heater knowledge into action. By providing quality content and expert guides, Adam hopes to help anyone looking for expert water heater advice.

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