With the frosty winters fast approaching, you definitely have to consider a shower-unit that gives you a constant pressure hot water supply as and when you require it (without making your utility bills run sky high).

Though there are several shower-unit-unit types available for you to choose, electric shower-units are a very good choice for many reasons. They are hassle-free shower-units requiring very little maintenance, they are good to look at and provide you hot water on the go without consuming a lot of energy in the process.

If you decide to opt for electric shower-unit-units, you would have to choose between gravity fed shower-units which operate with water supply from a small tank attached either in the attic or the loft of your house; or mains fed shower-unit-units, which are connected to the main water supply tap directly. Each type of electric shower-unit has its own advantages and disadvantages to consider.

A Gravity Fed shower-unit-unit System

This system comprises of a cold water storage tank situated on the attic at a higher altitude than the hot water cylinder and provides you warm water at a low pressure. The gravity fed electric shower-unit systems are one of the most common shower-unit systems in the UK since they are cheap, they require very little maintenance, and can be compatible with any heating element available – from solar heaters to electric coils.

The Advantages:

  • A very safe water heater system with many vents available to ensure even more safety in the bathroom
  • Depending on the height difference between the storage tank and the heater, you can have the required pressure. For instance, a 20 meter difference would give you almost 0.4 bar pressure (which is too low, but we could attach booster pumps to increase the pressure)
  • This heating system is the only system to which booster pumps could be attached for more efficiency
  • The pressure stays the same even if someone flushes a toilet somewhere else in the house

The Disadvantages:

  • There is very low pressure in gravity fed electric shower-unit systems and needs a supplementary booster pump to bolster pressure and water flow.
  • The expenditure thus equals that of other pricey water heating systems.
  • Booster pumps create a lot of noise and vibrations making these shower-units a bit noisy


All in all, the gravity fed electric shower-unit produces warm water at less pressures and is cheaper than most other shower-units.

A Mains Fed shower-unit System

Contrary to the gravity fed electric shower-unit system, a mains fed electric shower-unit would directly be fed with cold water supply from the main water line. These shower-unit systems are elaborate in construction and set-up and are expensive compared to gravity fed shower-unit systems. Hence, before you choose the mains fed system, you must make sure that the water flow in your mains supply is even.


  • There is high pressure hot water supply
  • For people with no header tanks on their lofts, this shower-unit system provides a wonderful respite.
  • Moreover, there is no further expense in the form of booster pumps et al.


  • They are extremely pricey as far as installation is concerned. Moreover, they need considerable space in your bathroom.
  • They are completely dependent on the pressure of the incoming mains water supply. If for some reason, the mains water supply isn’t even, the entire set-up falters. If someone flushes a toilet or the washing machine starts filling with water the pressure will drop and the shower-unit water temperature will go up to uncomfortable levels


Though very expensive and subject to fluctuations, the mains fed electric shower-unit is wonderful experience if you are living on your own and can guarantee that nobody will turn on a tap while you are in the shower-unit and cause the water temperature to fluctuate wildly.

Your Decision

If you still have a bath tub, take it out and put in a shower-unit because water and energy prices are only going to go up in the next 40 years and the sooner you start reducing your bills the more money you will have in the bank to spend as you choose. The gravity-fed shower-unit is the better option because the water temperature stays constant even when other taps are turned on. It is far safer and more enjoyable to have a shower-unit where the water temoerature can bre relied upon to stay constant all the way through your shower-unit.