Shower Pump Fitting Advise

20 Oct 2010
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United Kingdom
Hi All

Looking to fit a shower pump after having a read I will need to fit an Surrey flange on the cylinder to stop air getting in the pump.

Any tips to make the fitting and running of the pump easier would be a great help.

Many thanks
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You don't have to use a Surrey flange. The purpose of the flange is to prevent the air bubbles that rise to the top of the cylinder when the water is heated being sucked into the shower pump. There are other ways to achieve this.

Both methods work because the air bubbles naturally rise upwards to the vent rather than down the shower supply pipe. I installed my shower 15 years ago, I purchased a surre flange, but couldn't fit it because the boss on my cylinder outlet was too small, so rather than buy a new cylinder I used the installation method shown in the first picture, and it works fine.

Make sure the pump isolation valves are full bore ball valves, not the isolation valves that most DIY sheds sell that reduce the diameter, these can impeded the flow of water to the pump.

The cold feed should come directly from the cold water tank, don't be tempted to use the cold supply feeding the cylinder. Because this pipe is re-filling the cylinder as you use the hot water, it may not be able to supply sufficient for the cold supply to the shower as well.

When you select a pump the manual will give more detailed information relating to the producd you select.
Fitting a proprietary flange is strongly advisable & for most pump manufacturers a side fitting Essex flange is the preferred option. A 45 degree take off the vent works to an extent but a flange is by far the best method of achieving an air free supply. Get the design of your system wrong & you will suffer continual air locks, flow switch trigering causing the pump to pulsate &, at worst, early pump failure. You may also invalidate the warranty of some pumps if you don’t fit one.
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There are some pumps available that are designed to be fitted directly onto the DHW pipe.

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