Showering With Electric Showers - Are They the Best Option For Showering With Combination Boilers

Electric Showers are a solution to a problem not always are they the best option for showering performance.

I hear customers all the time saying to me "my plumber say's I need an electric shower as I have a combination boiler" why? are they scared of committing themselves to using the hot water that the combination will produce, the truth is they are.

The problem often is that to win the job the plumber is quoting for a cheaper boiler although they will all perform well at 80-100,000 Btu's for the central heating side of the boiler the domestic hot water performance is always not important to the consumer when taking up a quote, but this is one aspect that is going to fill your bath in good time and give you the shower that you dream of.

If you are reading this article and have not yet committed to your new heating system or an electric shower then these are the main questions to ask of the installer about the boiler and your water system.

Will the boiler heat up my house.
What Domestic hot water flow will the boiler you are suggesting produce at 38-42 degrees.
What pressure do I have at the mains water supply.
What flow rate do I have on the cold water supply.

If he cannot answer these questions then he is probably not the right man for the job.

Remembering that you need a good constant pressure and a decent flow rate into the property to get any instantaneous heater to perform well whether it be a boiler or an electric shower.

An electric shower is a good choice if your property suffers from the following issues.

Small hot water storage capacity.
Combination boiler with a Low flow rate.

Requirements for the installation of an electric shower.

Minimum running pressure 1.0bar.
Spare 30amp fuse minimum for 7KW and 45amp fuse for 10.5Kw showers

The installation of an electric shower can be expensive not necessarily from the plumbing point of view if you have the right water supply, but from the electrical installation, you will need for lower power options a 6mm cable or higher powered units 10mm run from the consumer unit (fuse board) to the shower and with the likelihood of having to fit a RCD (Residual Circuit Device) and a double pole switch and in some cases an extra fuse board. I have had customers that have had an electric shower installed and there main fuse into the property is not man enough, it does not take a lot electric cooker, electric water heating, storage heaters, kettle then add an electric shower then bang the lights go out.
Sorry this is the bit where I recommend always consult a Qualified electrician.

You can expect a flow rate of between 4 - 8 liters per minute out of an electric shower depending on the supply temperature and the power of the electric shower. On mains this will be about 5 degrees cooler in the winter therefore the heater will have to work a lot harder when you are wanting hotter showers.

Other Options for showering are:

Power showers(gravity fed systems only)
A pump and a shower valve, you can buy all in one power showers (integral power showers) or for best performance a recessed shower valve with a separate pump.

Thermostatic Shower Valves(both gravity and mains fed)
The best performing showers available with the best designs, and the most options.

Manual shower Valves
Although these are cheap they can be quite dangerous for showering as they do not hold the temperature as a constant, and any other items being turned on will effect the temperature.
The should never be used with combination boilers or other modulating gas devices such as water heaters.