Installing a shower pump is probably the single most important thing you can do to improve your showering experience. And you’re more likely to get a long and trouble-free life from your pump if you follow some simple rules when you’re planning it.
First of all you need to ensure that there is enough pressure from the tank in the loft to fire up the pump when the shower mixer or tap is opened. If you’re going to install a positive head shower pump, the minimum inlet pressure should be 0.2 bar or 2 metres. You can work this out by measuring the height from the base of the cold water tank to where the shower pump is to be sited. There should be also be a minimum height of 10ins (250mm) between the water level in the cold water tank in the loft and the shower rose. If it is less than this, you may not get the 0.5 litres per minute flow that is needed to activate most shower pumps.
The cold water header tank should be of at least 225 litres (50 gallons) capacity to maintain supply to the hot water cylinder and the shower pump.
When you’re planning where to place the shower pump, position it where it can be easily accessed once it’s installed. This will make it much easier to service it or clean the filters later on. It is permissible to place the pump under the bath but regulations dictate that a tool must be need to open the bath enclosure to get access to the pump.
To be absolutely safe, you must ensure that the pump is not covered or at risk of being covered. If this happens, then the motor could overheat and cause serious damage to the pump. This is particularly important if you’re planning to have the shower pump installed inside an airing cupboard.
Likewise, the shower pump must never be exposed to very low temperatures, so make sure that the location you’re planning to site it in is always guaranteed to be frost free.
While on the subject of safety, never ignore regulations when it comes to installing any electrical product. To comply with wiring regulations, an enclosed shower pump must be sited at least 2ft (600mm) away from the shower tray or basin.
The pump can be connected to the house’s electrical supply from a 230v switched spur off a ring main. It should never be connected to the supply for the hot water cylinder immersion heater or any other high-load installation that needs a dedicated supply.
Sometimes shower pumps can be slightly noisier than people expect. If you’re
concerned about noise, you can reduce the potential for this by siting it on a small concrete foundation about 2ins (50mm) thick. Alternatively, placing it on a concrete building block will do the same job. Never screw your shower pump to the floor.
You should always be able to isolate the water supply both to and from the pump. Fit a 22mm full bore isolating valve to the cold water pipe that supplies the pump. Pipework should generally be 22mm to reduce flow resistance to and from the pump. Furthermore, best practice dictates that the pump should be supplied through 22mm pipework irrespective of whether it has 22mm or 15mm connections.
To prevent air entering the pump, you should have a Surrey flange fitted to the top of the hot water cylinder if the pump has 15mm connections. An Essex flange should be used with pumps with 22mm connections.
Always make sure that you use the flexible hoses supplied with your shower pump to link to both the incoming supply and the outgoing delivery pipes. Flexible hoses are less prone to vibration from the pump and should help reduce noise and prevent damage to the pump itself.
Make sure that the pipework is thoroughly flushed prior to connecting the pump. This will help prevent debris entering the pump and impairing its operation.
Once installed, the shower pump and the pipework should be primed. Do this by switching the electrical supply off and running a bucket of water out of both the hot and cold sides until it runs clear. This will prevent air becoming trapped in the pump once it is commissioned.