Install Pump for Electric Shower
Choosing the Correct Pump
Selecting the correct pump for an electric shower is not straight forward, the simplest option is to use a negative head single impellor pump like the Salamander ESP 80 CPV as this will work for all electric showers, most standard single impellor pumps will not operate correctly as they rely on a flow of water to activate, this flow is usually 1 litre per minute, with electric showers fitted off of a gravity fed water tank that is usually not achievable also some electric showers will not let any water pass through the shower unless there is at least 1.0 bar static pressure.
For this reason I am basing this how to install a pump for an electric shower guide based on a Salamander negative head single impellor pump which will produce 2.4 bar pressure and easily maintain 1.0 bar running pressure.
Connecting to a Cold Water Tank
The cold water storage tank should be at least 600mm above the body of the pump. You will need to connect to a cold water storage tank of 50 gallons (225 litres) and position a 22mm tank connector outlet on the opposite side of the tank to the fill valve. It is good plumbing practice to fit a 22mm full bore isolating valve at this point.
Remember To Always Flush The Pipe Work!
Connecting the Pump
You are now ready to connect the pipe work to the inlet side of the pump. Once the inlet AV (anti-vibration) coupler has been fitted to the pump fit the outlet coupler turn off the built in isolation valve on the outlet AV coupler, turn on the full bore isolation valve from the cold water storage tank and the built in isolation valve on the inlet AV coupler.
You can now prime the pump and supply pipe work of air to do this you simply drain off a bucket of water through the pump with the electrics off using the outlet isolation valve as a tap.
Connecting the outlet of the Pump to the Electric Shower
You can now connect the pump to your 22mm outlet pipe and at the highest point you will fit a manual air vent (this is in case the pump or pipe work needs priming in the future), now run your feed to the electric shower you can reduce to 15mm (connection size standard for electric showers) closer to the shower and making sure that you fit a local full bore isolation valve at an accessible point. Now flush your pipes again. You can now make the final connection to the electric shower.
Turn on the outlet pipe from the pump and the inlet pipe before the shower, turn on the electrical supply to the pump it should run for about 20 seconds creating the required static pressure required for operation of your electric shower.
Make sure that you read the commissioning instructions that come with your ESP 80 CVP pump to set the pump to negative head operation.
That’s it happy showering…..