Electric Shower…or Tankless Water Heater?

The electric shower is common in the UK and South America but not so much in United states.  The reasons it hasn’t caught on yet may vary, perhaps since the unit installs inside the shower, people in the US are a little freaked out about having a 220v appliance inside the shower with them?? If you don’t know basic household wiring then this can seem pretty intimidating. These units replace the old hot water heater with a large 40 or 50 gallon tank and heat water as you go therefore eliminating the need for a large tank to store heated water.  There will be pros and cons to every system but it should save energy since it only heats water as needed.  Whole house units are either powered by electricity or gas fired. When a hot water valve is turned on, they kick on and heat the water. So, in a nutshell, cold water is supplied and hot water is sent.

Electric showers are consider a point-of-use appliance. In other words, it only works where it’s installed…the shower.  When you turn the shower on, they heat the water by passing it over a heating element mounted inside the shower. Once installed, they sit idle ready to heat your shower, day-in and day-out. They max temperature is thermostatically controlled for safety and some come with setting pre-sets so that you can change to your preferred shower water temperature with a push of the button.

A dedicated electric shower comes complete with the showerhead and hose that attaches to the heating unit. A slide bar mounts close to the wall allowing you to adjust the shower head up or down. Of course you can always remove the showerhead and use it as a hand held unit.

Do you live in the United States? you’ll be hard pressed to find one at your local home center, try the Internet instead.  Electric Showers haven’t caught on yet. I’ve searched for units here in the US but the only thing close to an electric shower are varying sizes of tankless water heaters, most of which are not recommended for a shower. Keep that in mind since they aren’t recommended for showers they don’t have the features an electric shower has like preset temperature settings. I have, however, found some questionable models on Ebay. Be sure to do some serious research before purchasing.

Bosch manufactures several different sizes of electric tankless water heaters. They range from Supplying endless hot water to one sink at a time to the whole house.

None of the local plumbing supply stores I’ve contacted have electric showers, only electric tankless water heaters. The one they offered required it’s own 120 watt circuit panel! That doesn’t sound cost efficient to me. The reviews I read, on the Bosch whole house unit, (supposed to replace a 40 gallon water heater) was less than stellar.

Power consumption

After much research, I’ve found that every unit requires a dedicated 220V circuit and at least a 40amp fuse. The house unit supplied by my local plumbing supply store required a dedicated 120 watt sub panel! That doesn’t sound cost effective to me. In my opinion, a gas fired whole house tankless water heater is a much better option. The power consumption of the Bosch tankless water heaters ranged from 9.5 kw to 12 kw. Compare that to the electric showers in the maximum heating level which was 5.5 kw for 120v to 7.5 kw for the 220v units.

The energy intake may seem high but keep in mind that they only use energy when being used and sit idle most of the time. The old style water heaters  must keep the water at a constant temperature and turn on anytime the water dips below the set temperature. If you want to install a whole house, gas fired tankless water heater, remember  that a reduction of heat  will occur in the hot water lines that travel from the tankless water heater to the faucet. This reality is a characteristic you simply can’t change unless you install a point-of-use electric shower and an electric tankless water heater at every sink. So electric showers can save energy compared to gas central heaters when you install a point-of-use electric shower…in theory anyway.


The heating elements are coils made from nickel or an alloy (bend) of nickel and chromium. The element is sheathed much like
the coils used in oil heaters or radiators – they provide more safety since there is insulation between the electrical parts
and the water.

Electrical appliances sold in the USA must pass electrical safety standards. An independent safety science company like United Laboratories (UL) or the American National Standards Institute (ANSI) reviews products and if they pass…gives them their seal of approval recognized by a states building code enforcement agencies. If you’re looking at the electric showers available on Ebay, be sure to ask if they are UL or ANSI certified. If the seller can’t tell you…run.

Are you planning a DIY Bathroom renovation project and want to install one of these units yourself? Here’s what you’ll need to do:

You will be required to pull electrical and plumbing permits and if the unit isn’t approved by a US independent safety science company like the ones talked about above…be prepared to sell the inspector on the credentials of the European independent safety science company. Bottom line is do your research. If you’re having it installed, don’t let your plumber or
electrician tell you that you don’t need a permit. Contact you’re state code enforcement agency and find out for yourself.

To pass electrical safety Standards, modern electric showers are made of plastic instead of the metallic casings like in the
past. This electrical appliance works with higher  amperage’s  than a washer or a dryer so the installation of electric showers needs careful planning and must be made directly from the electrical distribution box , with exclusive 6 gauge wires, electric connectors for 50A and a ground system. Each manufacturer’s recommendations may differ slightly so check the  owners manual for appropriate installation  .

Older homes fitted with aluminium wires should never be used as the wires can overheat and cause a fire. With this said, it really shouldn’t be a concern since these units require their own circuits…new copper wires with the recommended gauge size have to be installed. If you’ve got questions…call your local building code enforment. They are usually very helpful.