15 Common Problems With Electric Water Heaters | Must Read

Usually, very few issues arise with an electric water heater, but when they do, it is important to understand how to troubleshoot. Any new appliance usually comes with a guarantee, but once you are out of that period, it is up to you as to whether you pay for the repair, buy a new one or fix it yourself. You shouldn’t need a new heater in under ten years, so we will take a look at what can possibly go wrong.

Common issues that affect your Electric Water Heater

1. Water Pressure

If the water pressure is really low there may not be enough flow to sustain the electric water heater. This is common in rural areas where water is often pumped from rivers or dams.

To sustain an electric water heater you will need a specific volume of water, so, consult the experts to make sure enough water is pumped through the system to meet the manufacturer’s requirements. If you have insufficient flow, the heater could fail and you would void your warranty.

2. Your Electric Hot Water Tank is not Big Enough

If You have a 40-gallon electric tank, this size will take a little longer to heat, as the smaller the tank the faster it will heat, and this size will take around 45 minutes to be hot enough for a shower in winter.

Factors that Affect the Heating Speed

  • size of the heater
  • season, it takes longer to heat up in winter, because it starts from a lower point. In summer, water will heat faster.
  • the flow rate of water
  • distance of the tank from the shower

Water Tank Sizes

The standard sizes for horizontal hot water tanks range from 180-3500 gallons, but 180 gallons is too big for a small family, so we will look at calculating the correct size for your family.

tank electric water heater

A family of four will require a 50-gallon tank, if you decide to go smaller this is a false economy as the tank will overwork and may break down. if you want to calculate how much water you actually use, read the water meter, write down the reading take it again a month later and subtract the first reading then deduct about one-third for cold water use, this will give you a rough calculation of your monthly water use. It will give you a good idea of how big a tank you need.

Of course, some times of day are busier than others and can be considered peak- hours. For instance, if you are all getting up, showering, between 6-8 am, doing laundry, and then leaving the house for the day, peak hour is in the morning when you are using your most water.

Below is a rough calculation of the size of the water tank you will need based on the size of your family.

Family Size People and Capacity of Water heater

  • 1-2 people -23-36 gallons
  • 2-3 people 36-46 gallons
  • 3-4 people 46-56 gallons

3. Check the Thermostat

If you have a defective thermostat it is important to identify it quickly. ( It looks like a small box with a heat-regulating dial).

If you find that the water is becoming cold, the tubing in the thermostat could be failing. If you ignore it, and it suddenly gets really hot you may have a massive energy bill for constantly boiling water, if it goes down low you will be having cold showers, so it must be fixed.

TIP: if the power board keeps tripping it is most likely the thermostat needs replacing.

4. Sensors Fail in Your Tankless Electric Hot Water System

This hot water system is an energy-saving system, that must be installed by expert technicians. This system instantly heats the water as it flows through the device. Copper heat exchangers are preferred in these units due to their ability to conduct thermal heat. Tankless heaters may be installed in your home without a central water heater. People living alone often find this method ideal for their hot water needs.

Advantages are:

  • You will always have a limitless supply of hot water in your home.
  • Potential energy savings as you only pay for energy when the hot water is in use.
  • There are no standby energy costs for this method.

The heater operates by being normally turned off, but has flow sensors that activate when the water is flowing through them, a copper heat exchanger is warmed by electricity. If the sensors fail the water heating device won’t turn on, and you will need a technician to come and replace them.

5. Power Failure and Reasons for Cold Water

If the electricity supply fails, then you won’t have any hot water. If you live in a remote area prone to storms and snow it is a good idea to have a standby generator, otherwise, you will find no electric water heater without electricity, and this can go on for a few days until power is restored.

In remote areas the pipes sometimes freeze, and when this happens turn off your electric water heater as no water is getting to it.

There are other reasons for power failing to your electric water heater, so firstly, Do some troubleshooting

  • Check the fuse box, make sure the trip switch hasn’t tripped.
  • Check the reset button on the electric water heater panel
  • If your water heater is really old it may have reached its use-by date so check how long you have had it.
  • The element could be faulty, if it is not working properly it can be replaced

6. Water Looks Dirty

This is usually a sign that your electric water heater is failing, and the inside of your tank is beginning to wear out. Don’t leave this problem unchecked, as it can totally erode allowing rusty hot water to flow out and cause a lot of damage to your home.

Another reason could be that if you are living remotely the supply could be dirty from floodwaters, so turn on the tap and if the water looks brownish this may be a global problem. Obviously don’t drink it, but is usually okay to shower and do the washing with slightly dirty water.

Flood water won’t harm your hot water system, but it may discolor the whites in your wash. It is better than no water at all.

7. Water can Smell Funny

There could be bacteria in the water especially following a flood, or if your water comes from a well. This is a horrible problem, so get an expert plumber to come and flush your tank. Use laundry sanitizer in your washing machine to kill the bacteria, and combine it with a hot wash.

Have very quick showers until the problem resolves. If the plumber thinks that the problem is in the tank, you may need to clean it with a bleach solution. If you are using tank water in an off-the-grid rural area, a common practice in some places, check the roof and drain pipes for dead animals that may be contaminating the roof water run-off.

If you are off the grid, you will notice a huge fluctuation in the quality of your water, depending on supply and demand. When the tanks start to get low, you may need to buy water usually bought in by a contractor and this can be costly. It is better to have a few tanks and rely on the rain to fill them up, and an underground storage tank is ideal and will give you nice clean water for your electric water heater.

Some areas have very hard water, and this can also affect your electric water heater. Some heaters are better able to deal with hard water than others. Hard water contains excessive minerals and over time they build up in your water heater reducing its capacity and causing inefficiencies to occur if it collects near the element water can take longer to heat up. Hard water can wreck your appliances, especially when it contains calcium and magnesium, to minimize damage do some troubleshooting.

  • Lower the water temperature in your water heater permanently to stop minerals from building up
  • Flush out your water heater by keeping the cold water valve open and allowing the water to flush through
  • Purchase a water softener, a whole house water softener need to be used before the water enters your home
  • Consult a local plumber who will understand the issues involved
  • If you are new to country life there will be lots of people ready to advise you, especially on the most resilient appliances for hard water.

if scale builds up in your tank, it can cause the tank to make noises. If this happens drain the tank and have it professionally descaled. Ask the plumber about this problem and the cost involved. Once again it is caused by the build-up of minerals.

8. Is Your Electric Water Heater Leaking?

This may be a simple problem, so before you worry, take the time to eliminate the minor issues first. The problem could be caused by a loose drain valve. You will need to tighten the drain valve, and if that doesn’t work replace the drain valve.

water heater leaks

If it is not the drain valve turn off the electric water heater and look further.

  • Purchase a voltage tester to confirm that the power is off when you check the wires. This will keep you safe when touching wires.
  • Turn off the water main
  • Turn off the power at the main
  • Identify the leak

Once you find where the water is leaking from, you may need to phone the plumber, as it is quite likely that a part needs replacing.

9. Your Water is too Hot

If your electric water heater is too hot, try turning down the thermostat. If you can’t get the temperature down, the thermostat is probably faulty,

this is dangerous as someone could be burned. In the past, many people have been burned, especially children, by the hot water being too hot.

Now the law states that the maximum temperature of the bathroom water should be 50 degrees. Under WH&S (work health and safety law), the law is in place to prevent scalding. So, if you find that you are unable to regulate the temperature of your hot water, and it seems to be boiling, you need to call a technician.

Water over 51 degrees can cause a major burn in as little as 30 seconds, so the bathroom temperature is set by law, and all plumbers know this and adjust the heat accordingly. In residential facilities, the thermostatic mixing valve must be tested monthly with the temperature recorded on a WH&S log sheet kept to be tabled at WH&S meetings, this is part of maintaining a safe workplace at law. (WH&S 2000).

Even if the electric water heater is not overheating, you are still required to have the plumber check the heat annually. Maintenance is important in keeping your home safe, and your children free from burns.

If the hot water continues to overheat, you must either replace the thermostat or replace the electric hot water system, depending on what the technician says. A child under 7 years should not be left alone to bathe or shower.

The parent should half fill the bath with water and if you wonder what the temperature is, you can purchase a simple bath thermometer from the pharmacy to test water heat. Stay in the bathroom to make sure that they don’t add more hot water, or drown. Since the law introducing hot water temperature in the bathroom came in, the instance of burns in children has markedly reduced.

10. Noisy System

Within your electric hot water system, is something called an anode, and this may need replacing. An anode is a positively charged electrode involved in the heating process, and it may be worn out. This is done by a plumber, so ask him/her to take a look.

The other reason is sediment around the element, and when this happens the system requires turning off and draining, to get rid of the debris.

11. Occupies too Much Space

As your family grows, space is at a premium. If you decide that you need more room in the bathroom your electric hot water heater can be moved.

If you can wait until you get a new one, many of the electric hot water heaters can now be placed outside and plumbed into the house. This depends on your climate zone. However, this worked brilliantly on my last renovation allowing a bit more space in a small downstairs bathroom.

Although this is not a serious problem, it can make all the difference to you and your family.

12. Your last shower is cold

When there are a few of you showering in the morning, by the fourth shower the water may be cooling or cold. There are various reasons for this.

  • Your electric water heater may be too small for your growing family.
  • Your electric hot water heater could need replacing.

This is an annoying problem, and until you can address it you may need to make a night/morning roster for the kids.

13. You Need a new Hot Water Heater but Can’t Afford One

This is tricky, but not insurmountable, as hot water is considered an essential requirement. If you go along to the showroom, take a look at the

electric water heaters, and ask the salesman if they have a payment plan, most do and for very little interest you can have your new electric water heater installed now and pay over a year or two.

14. Permanently Luke Warm Water

If your water is tepid, you may think that this is quite pleasant in summer, but once again there are risks. After a while, Legionnaires Disease-causing bacteria grow in the lower water temperatures in your tank. If the hot water tank is below 60 degrees (140 F) for a few days you could be at risk.

Legionnaires cause a nasty respiratory disease, and the bacteria are inhaled during showering, unfortunately, electric water heaters have an increased risk. If the bacteria gets into your system, pipes, and showerhead where it breeds it will harm your family, especially the old and frail members, and the very young are more susceptible.

The reason that your electric hot water system is more susceptible is that the temperature at the bottom of the tank is 25 degrees, creating an ideal environment for the Legionella to grow. So if you think that you can go for the next three months with tepid water, think again, as it is a health risk.

Legionnaires Disease can be fatal, causing severe pneumonia. So don’t turn your electric water heater down to save money, as it is a false economy. The World Health Organization recommends that water be heated and stored at 60 degrees, If you are in a cold climate like Canada, go a bit higher, because the water at the bottom of the tank is cooler.

Of course, in Residential facilities and Hotels, the water is regularly tested to ensure the tank is free from Legionella, so you should be perfectly safe when staying in good accommodation.

15. Cleaning the Electric Water Heater

You can clean your tank using vinegar if you feel confident to do so. There are a few simple steps to follow to complete this process.

  • Turn off the power to your system
  • Turn on a hot water tap over your bath or basin to prevent a vacuum from forming, leave the tap running while you get started.
  • Attach a hose to the drain valve, and put the other end of the hose into the laundry sink or a large bucket.
  • Turn off the Cold Water for the Hot Water Tank by placing the lever in the off position.
  • Drain some of the water from your hot water tank.
  • You can now turn off the bathroom tap.
  • Locate the anode knob on your hot water tank, near the top with a lid covering it.
  • Loosen the anode and remove the anode rod from your hot water tank.
  • Pour in 2-3 gallons of vinegar using a funnel, once you have added all the vinegar remove the funnel.
  • Put the anode rod back, or replace it with a new one, make sure it fits snugly.

Now your tank will be clean, and no bacteria will survive the vinegar. Run it through to make sure it flushes out the residual vinegar and then wait for your next shower. Even the water will smell fresher, and you can use either white or brown vinegar ( white is a cleaner look).

Your electric water heater should now be in optimal condition because the vinegar will take away the build-up of mineral deposits, from now on flush the tank from time to time to keep clean.

Trouble Shooting Your Electric Water Heater

All of the above troubleshooting tips are simple and straightforward. As you are dealing with electricity it is best to call a skilled plumber or electrician if you have ongoing problems, as we should never try to fix electrical issues ourselves.

Have the tradesmen cards on your fridge magnet, in case you need to call them in a hurry. Once your electric water heater is ten years old, start planning its replacement, as you don’t want to leave it until an emergency occurs. If the water becomes slightly discolored arrange for a replacement sooner rather than later.

If you have a two-story home with several bathrooms, it is a good idea to have more than one electric water heater, as water going upstairs from downstairs ends up wasting a lot of heat in transit.


Your electric hot water heater is not hard to look after, as in reality very little goes wrong with them, and initially, the heater should still be under warranty allowing any immediate problems to be ironed out. So when it is new, put your paperwork in a safe place so that you can check the details when necessary.