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The only thing worse than a shower that won’t turn on is a shower that unexpectedly turns ice cold while you’re in it! Either way, shower problems are frustrating. However, there are relatively simple ways you can remedy electric shower issues. Our property management experts at Flex Living fix electric showers every day, so we’ve compiled this list of the main issues we see, from electric showers with no hot water to showers that won’t turn on at all.
What Are Electric Showers and How Do They Work?
Electric showers are one of the UK’s most popular showers, alongside mixer and digital showers. How do they work? Conventional electric showers use an electrical current element to heat cold water that passes through a heated coil and then exits at a higher temperature. Since this system uses a separate built-in heating element, you won’t struggle to maintain heat and water pressure when multiple taps are turned on in your property. There’s also no need to wait for stored water to heat up because it heats as it passes through the electrical element.
Electric Shower Has No Hot Water
If your electric shower has no hot water or is not heating up, you could have a faulty thermal switch or an excessive limescale build-up.
1. Check Thermal Cut-Out Switch
If no hot water comes from your electric shower, it could be due to the Thermal Cut-Out (TCO). The TCO is a safety component installed in electric showers; it cuts power to the heating element if the unit’s temperature overheats. The TCO can cut out and reset even if the shower overheats slightly. Sometimes, the TCO might start working again once the shower has cooled down, but not always. If your thermal cut-out keeps cutting out, you may need to replace it. Watch this tutorial on how to replace a TCO by yourself. Alternatively, call a heating professional to take a look for you.
Before fixing a new TCO, see if you can find the cause of the cutting out. A TCO that repeatedly fails usually signifies a blockage somewhere else in the shower system. For instance, a blocked shower head, blocked inlet filters or a blocked hose. In most cases, the culprit for these blockages is a build-up of limescale.
2. Fix Limescale Build-Up
As with all electrical water heating systems, electric showers are prone to limescale build-up outside and inside the shower head, causing blockages in the system. Particularly if you live in a hard water area, your shower might have a limescale problem. Limescale build-up can increase back-pressure within the system, which can then cause pressure relief devices to blow.
To fix limescale build-up in the shower head, follow these steps:
- Wipe off any dry debris on the shower head
- Mix equal parts white vinegar and water in a plastic bag
- Place the bag with vinegar mixture over the shower head and seal it with a rubber band or hair tie
- Allow the shower head to soak for 20 minutes
- Remove the shower head from the bag and rinse it to remove any remaining debris
Unfortunately, limescale build-up inside the shower unit (for example, in the heater coil) is more difficult to prevent. If the build-up amasses over a certain level, the heater coil will reduce its function and your electric shower will lower its energy efficiency. As a result, you may need to get it replaced by a qualified plumber. You may also want to get a limescale filter or water softener installed to prevent limescale building up in the future. We recommend using Check-A-Trade to find experienced, fully reputable, affordable trades workers in your area.
Electric Shower Changes Temperature Inconsistently
If your shower suddenly alternates between hot and cold water, there may not be enough water feeding into the shower.
1. Check for Faulty Pressure-Balancing Valves
If your shower is sporadically switching between hot and cold water, there may be an issue with the valves and not enough water getting to the shower. Check that the valve delivering water to your property and the valve on the line to the shower are completely open so as to allow enough water flow to your shower. If both valves are open, the problem could lie with the flow valve inside the shower. In this case, you’ll probably need to call a plumber to replace the faulty component. We recommend using Check-A-Trade to find experienced, fully reputable, affordable trades workers in your area.
2. Check the Water Pressure
An electric shower should have a pressure reading of 1.0 bar for optimal functioning. You can buy a hand-held pressure device from a hardware store to test this. Alternatively, you can try listening for any clicking noises that indicate low water pressure. The most common cause of low shower pressure is a build-up of debris and limescale in the shower head, so prioritise cleaning and descaling your shower before anything else.
3. Clean limescale build-up
See ‘Fix Limescale Build-Up’ Section under ‘Electric Shower Has No Hot Water’
1. Check for Limescale Build-Up
First, check for any limescale build-up on the shower head that could impact the water flow. If there is noticeable debris, follow the steps under the ‘Fix Limescale Build-Up’ Section under ‘Electric Shower Has No Hot Water’.
2. Check/Change the Solenoid Coil
If you have checked for limescale and the water pressure is still low, check the solenoid coil. This is a component found in many electrical appliances; it uses a wire firmly wrapped around a metal core to create an electromagnetic field, providing energy to open the valve and allow water to flow out of the shower. You can find the solenoid at the base of the shower unit. It is made up of the valve itself and a detachable coil.
So how do you troubleshoot a solenoid coil? It is best to call an electrician or a plumber to change the Solenoid Coil. They will most likely follow these steps:
To check the coil:
1. Turn off the power at the isolation switch and remove the fuse from the fuse board.
2. Turn the mains water supply off.
3. Double-check that the problem lies with the solenoid by using the two metres on the solenoid’s corresponding terminals. Check the reading.
4. If the reading comes to 3.5-4 kilo-ohms, then the solenoid coil is functioning as it should. If the reading is outside of this range, the coil needs replacing.
To change the coil:
1. Depending on the brand of the coil, you may either need to swap out the entire component or sometimes you can simply change just the coil.
2. Use two screwdrivers on either side of the top of the coil and ease it away from the rest of the valve
3. Twist the coil until it becomes loose from the valve, then disconnect the tube terminals
4. To fit the replacement coil, reattach the wires to the terminals and slide the component back into place.
5. Turn water supply back on, put fuse back in and turn the isolator switch back on
You can watch this tutorial on how to check and replace a solenoid coil.
Electric Shower Won’t Turn On
1. Check Consumer Unit and Fuse
If the electric shower does not turn on, you could have an issue with the circuit breaker. If you have reset the circuit breaker on your consumer unit and still have no power supply, check the fuse (usually located in a socket close to the boiler programmer with the word ‘Fuse’ on the switch and an orange light). If the fuse has blown and the circuit breaker is on, the fuse light will not be lit, even when the fuse switch is on. In some cases, there is no light and you need to use a voltage tester to check for power. Before replacing a fuse, ensure you turn off the power supply from the consumer unit first. We recommend enlisting the help of a professional electrician.
If the system keeps tripping or the fuse keeps blowing, you may have a leak somewhere (skip to ‘Water Leaking from Electric Shower’ section) causing the circuit to break, or you may have a fault in other electrical elements like the solenoid coil.
2. Check Solenoid Coil
The most common reason your shower won’t turn on is due to a problem with the solenoid valve coil. See the steps above under ‘Low Pressure’ to check the coil’s reading. If it reads outside the ideal range, the problem lies elsewhere in your shower.
3. Clean Limescale
Check for and clean any limescale on the shower head. If the shower still doesn’t turn on, call a professional to flush the system to remove any internal mass limescale build-up.
Water Leaking from Electric Shower
If you can see water leaking from your electric shower unit, it may be a sign of excess water pressure. Too much pressure will trigger the pressure relief device in your shower, so it tries to reduce pressure by releasing water from the valve at the base of the shower.
1. Remove Blockages
Leaking showers due to high pressure are often caused by a blockage. This blockage is most likely to be caused by limescale and debris accumulation (see ‘Fix Limescale Build-Up’ Section under ‘Electric Shower Has No Hot Water’).
If you have cleaned your showerhead of limescale and the shower still doesn’t turn on, call a plumbing professional to further inspect the issue.
2. Check Solenoid Coil
Check the reading on your solenoid coil. If the reading comes to 3.5-4 kilo-ohms, then the solenoid coil is functioning as it should. If the reading is outside of this range, then the coil needs replacing (see ‘Check/change the solenoid coil’ section under ‘Low Pressure’).
Summary of Electric Shower Problems and Solutions
Below is a summary table of the most common electric shower issues we encounter and the possible causes and solutions.
|No hot water
|- Check/replace thermal cut-out switch
- Check for/clean limescale build up
|- Check for faulty pressure-balancing valves
- Check water pressure
- Clean limescale
|- Check for/clean limescale build-up
- Check/change solenoid coil
|Won’t turn on
|- Check Consumer Unit and Fuse
- Check Solenoid Coil
- Clean Limescale
|- Remove blockages
- Check solenoid coil
Simple Solutions with Flex Living
Save your time browsing through endless articles and instructor manuals on how to fix your electric shower. By renting out your property with our property management team at Flex Living, we take care of all maintenance and repairs (with zero call-out fees and hidden costs!), so you don’t have to worry about all the technical stuff.