What Type of Shower?
Showers - Electric Showers vs Mixer Shower Valves
The type of shower that you can have installed during a bathroom to shower room conversion will depend on what kind of a boiler you have to heat your house.
If you have a modern combi-bolier then you have a choice of either an electric shower or a mixer shower. However, if you do have a combi-boiler, then in most cases it is far better to have a mixer shower installed rather than an electric shower. A comb-boiler, for those of you that don't know, is an instantaneous boiler. It provides heat to both your central heating system and on demand to your hot water taps. There is no hot water stored, instead as soon as you turn on your hot water tap the boiler fires up and heats the cold water drawn through it which then (after a short delay) exits your hot water taps at temperature.
Unlike an electric shower, a mixer shower simply takes both the hot and cold mains water and allows you to mix the two to get the right temperature. There is no wiring or electricity involved with a mixer shower, it's basically just a mixer valve, very similar to a kitchen or bathroom mixer tap, and as such much less is involved in their installation.
An electric shower, as the name suggests, requires connection to the mains electricity. Mains cold water is heated very quickly by passing around a very high power heating element. Unlike a mixer shower that requires connection to both the hot and cold water supplies, an electric shower only utilises the mains cold water supply and the heating is varied by the speed at which the cold water flows around the heating element. Because electric showers use only the cold water supply which is then regulated to provide the correct temperature, they invariably provide less litres per minute of water during your showering experience than a mixer shower which receives both hot and cold water at mains pressure. However, a bigger issue is that due to the high power, high current nature of electric showers, they cannot simply be tapped into the electric ring main or plugged into a 240v mains socket. No, because electric showers draw so much current they need an electric feed all of their own from your consumer unit (main fuse box). They need their own resettable MCB (Miniature Contact Breaker) which is a resettable fuse, and if your existing fuse box does not already incorporate one, an Earth Leakage Circuit Breaker will also need to be fitted. In most bathrooms there is usually a mains cold water feed close by in order to provide the water supply to an electric shower, but getting a thick heavy duty electric cable from the shower to your consumer unit is always a challenge; one that often requires carpets and floorboards to be lifted and numerous holes drilled in which to feed this cable through. And of course, the farther away your consumer unit is from your electric shower unit, the more difficult the task is made.
There was a time when plumbers like myself installed electric shower units as part of our job description, but recent government rules and regulations no longer allow us to connect up the electrical side of the installation. Now, a new electric shower unit installation requires testing by a Part P qualified electrician who will then provide you with a safety certificate. Needless to say I do have a Part P qualified electrician do the wiring and provide an electrical safety certificate in any job that requires the completely new installation of an electric shower. All this of course means not only do you have to pay the plumber to fit an electric shower unit, but there is now the additional cost of a qualified electrician. While we are told by the powers that be, that these new regulations are a safety measure and a deterrent to the 'cowboys' out there, it also adds considerable cost to the work - around the £120 mark! And I really doubt it makes the slightest bit of difference to the cowboys who I'm sure aren't going to let any new regulation slow them down!
Some people simply assume that a higher power electric shower will compensate for a lower water pressure, but it's not quite that simple. To function properly a high power electric shower may possibly require a greater minimum water pressure than a lower power electric shower. For example, Triton state that their 9kW - 9.5kW electric showers require a minimum of 1 bar of water pressure and a minimum flow rate of 9 litres per minute, but their 10.5kW electric showers require a minimum of 1.5 bar of water pressure with a minimum flow rate of 11 litres per minute - which sort of defeats the object if you are expecting a higher power electric shower to your low water pressure problem! Yes if you already have a good mains water pressure then the higher power electric shower can provide a greater flow of hot water, but it can come at quite a cost. The most popular electric showers have rating between 8.5kW and 9.5kW, if you install (or update to) a higher power electric shower, such as a 10.8kW or 11.5kW, then a much heavier electric cable is required, along with a larger MCB. The much heavier cable can be an absolute nightmare to feed from the shower location to mains consumer unit as it is more like a length of stiff pipe than cable. Furthermore, the length of cable and the route it takes will govern its current carrying capacity, meaning that an even larger cable may be required. And of course, this is all assuming that your consumer unit is capable of handling the high current drawn by a high power electric shower in the first place.
But anyway, whilst electric shower units do certainly have their place, due to the work, time and additional cost involved in installing a new electric shower unit, a mixer shower will nearly always be the best option if your house is already heated by a combi-boiler.
I should just add that electric showers do require a certain level of mains water pressure to function; however, if low water pressure is an issue then there are still other options available, such as pumped electric showers. Likewise, a mixer shower can be used in conjunction with a pump taking water directly from the hot water cylinder and cold water storage tank should you not have a combi-boiler and should an electric shower unit not be an option.
If you have a modern combi-bolier then you have a choice of either an electric shower or a mixer shower. However, if you do have a combi-boiler, then in most cases it is far better to have a mixer shower installed rather than an electric shower. A comb-boiler, for those of you that don't know, is an instantaneous boiler. It provides heat to both your central heating system and on demand to your hot water taps. There is no hot water stored, instead as soon as you turn on your hot water tap the boiler fires up and heats the cold water drawn through it which then (after a short delay) exits your hot water taps at temperature.
Unlike an electric shower, a mixer shower simply takes both the hot and cold mains water and allows you to mix the two to get the right temperature. There is no wiring or electricity involved with a mixer shower, it's basically just a mixer valve, very similar to a kitchen or bathroom mixer tap, and as such much less is involved in their installation.
An electric shower, as the name suggests, requires connection to the mains electricity. Mains cold water is heated very quickly by passing around a very high power heating element. Unlike a mixer shower that requires connection to both the hot and cold water supplies, an electric shower only utilises the mains cold water supply and the heating is varied by the speed at which the cold water flows around the heating element. Because electric showers use only the cold water supply which is then regulated to provide the correct temperature, they invariably provide less litres per minute of water during your showering experience than a mixer shower which receives both hot and cold water at mains pressure. However, a bigger issue is that due to the high power, high current nature of electric showers, they cannot simply be tapped into the electric ring main or plugged into a 240v mains socket. No, because electric showers draw so much current they need an electric feed all of their own from your consumer unit (main fuse box). They need their own resettable MCB (Miniature Contact Breaker) which is a resettable fuse, and if your existing fuse box does not already incorporate one, an Earth Leakage Circuit Breaker will also need to be fitted. In most bathrooms there is usually a mains cold water feed close by in order to provide the water supply to an electric shower, but getting a thick heavy duty electric cable from the shower to your consumer unit is always a challenge; one that often requires carpets and floorboards to be lifted and numerous holes drilled in which to feed this cable through. And of course, the farther away your consumer unit is from your electric shower unit, the more difficult the task is made.
There was a time when plumbers like myself installed electric shower units as part of our job description, but recent government rules and regulations no longer allow us to connect up the electrical side of the installation. Now, a new electric shower unit installation requires testing by a Part P qualified electrician who will then provide you with a safety certificate. Needless to say I do have a Part P qualified electrician do the wiring and provide an electrical safety certificate in any job that requires the completely new installation of an electric shower. All this of course means not only do you have to pay the plumber to fit an electric shower unit, but there is now the additional cost of a qualified electrician. While we are told by the powers that be, that these new regulations are a safety measure and a deterrent to the 'cowboys' out there, it also adds considerable cost to the work - around the £120 mark! And I really doubt it makes the slightest bit of difference to the cowboys who I'm sure aren't going to let any new regulation slow them down!
Some people simply assume that a higher power electric shower will compensate for a lower water pressure, but it's not quite that simple. To function properly a high power electric shower may possibly require a greater minimum water pressure than a lower power electric shower. For example, Triton state that their 9kW - 9.5kW electric showers require a minimum of 1 bar of water pressure and a minimum flow rate of 9 litres per minute, but their 10.5kW electric showers require a minimum of 1.5 bar of water pressure with a minimum flow rate of 11 litres per minute - which sort of defeats the object if you are expecting a higher power electric shower to your low water pressure problem! Yes if you already have a good mains water pressure then the higher power electric shower can provide a greater flow of hot water, but it can come at quite a cost. The most popular electric showers have rating between 8.5kW and 9.5kW, if you install (or update to) a higher power electric shower, such as a 10.8kW or 11.5kW, then a much heavier electric cable is required, along with a larger MCB. The much heavier cable can be an absolute nightmare to feed from the shower location to mains consumer unit as it is more like a length of stiff pipe than cable. Furthermore, the length of cable and the route it takes will govern its current carrying capacity, meaning that an even larger cable may be required. And of course, this is all assuming that your consumer unit is capable of handling the high current drawn by a high power electric shower in the first place.
But anyway, whilst electric shower units do certainly have their place, due to the work, time and additional cost involved in installing a new electric shower unit, a mixer shower will nearly always be the best option if your house is already heated by a combi-boiler.
I should just add that electric showers do require a certain level of mains water pressure to function; however, if low water pressure is an issue then there are still other options available, such as pumped electric showers. Likewise, a mixer shower can be used in conjunction with a pump taking water directly from the hot water cylinder and cold water storage tank should you not have a combi-boiler and should an electric shower unit not be an option.