Shower pumps explained
Buying a shower pump is the only way some people can get a good shower where they live. If you are looking for a shower pump, there are hundreds of shower pumps to chose from – so what are the things to look for?
The key to a great shower is:-
Gravity showers are sold which can give you an OK shower with as little as 1 metre head (0.1 bars). Raising the tank in the loft, or dropping the shower head, might be a solution to give you a better shower. The same effect can be achieved by adding a showerpowerbooster, which will add a minimum of 3 metres head to a standard gravity shower. Before you buy a shower pump, you could try changing the shower hose. Most shops sell small bore shower hoses, and not the large bore shower hoses that are available. This might be all you need. A change of shower head may also help. If you think that is not your solution, and even if, after changing the shower hose and shower head, you still only have 1 metre pressure (or less), then you could keep your existing hose and shower head and buy a water pump.
Traditional shower pumps are designed to boost the pressure to perhaps 1 bar (10 metres head), 2 bars (20 metres head), 4 bars (40 metres head), and in a particular millionaire’s house (who sits as a Dragon In Dragons Den), claims she has a booster pump which gives 8 bars (which is 80 metres head and would be more likely to cut of limbs rather than clean the skin).
For those not in the millionaire bracket, we have to look at practical solutions at everyday prices. In my own home the gravity shower has 1 metre of head which is OK but not good, and adding 3 metres head with a showerpowerbooster is more than enough to get a nice powerful spray pattern.
Some electric showers give as little as 3.5 litres a minute, which some manufacturers would argue to be a good shower. I would suggest this is probably too little to get rid of suds easily and being electricity it’s a very expensive way to heat water. A showerpowerbooster will typically give 6 litres a minute, but this will depend on the shower head. A power shower will typically run at 12 litres a minute or more, which makes them twice as expensive to run, and a typical large family will empty the hot water cylinder before everybody has had a shower.
The best temperature for a shower is personal choice, but a typical person wanting a hot shower will want the temperature to be between 42 degrees centigrade and 46 degrees centigrade. Water temperature is normally controlled with a mixer valve or a mixer tap, which is either manual or automatic.
For those with gravity fed hot and cold, you will normally get away with a single pump boosting the hot. This is helped by the fact that water in the hot water cylinder is at approximately 55 degrees centigrade and the cold water tank is about 15 degrees centigrade. To get a hot shower, you need to mix more hot water than cold water. In addition there is the ability of the valve or tap to balance pressures. The need for more hot water and the ability of the valve to balance pressures should result in the need to boost the hot water only. For those that have very low cold water pressure you could also get away with a single pump if you simply turn down the hot water cylinder temperature.
For those that use a gravity boosted hot and want to use a mains pressure cold, you are better to go for a hotter temperature in the cylinder, but due to the mixer valve ability to balance flows again you will get away with a single showerpowerbooster.
Some customers will have mixer valves that are not very good at balancing flows or very low pressure on the cold. Perhaps 1 in 10 customers which will require two showerpowerboosters (on the hot and cold).
Traditional pumps which supply 1 bar head (10 metres) will always need to pump both the hot and the cold because pumping just on the hot will overwhelm the cold supply at the mixer valve (again big is bad).
Large pumps are prone to overheating and are not serviceable by the customer. If the pump goes wrong, the only option is a new one. Shower Power Booster pumps can pump against a closed head without damage for prolonged periods, and if they do go wrong can be fully serviced by a competent DIYer (see video below):-