Grundfos STR2-1.5 C Twin Impeller Regenerative Shower Booster Pump 1.5 Bar

Hi, This particular pump is a positive head pump. Thanks. Technical Team.

Hi, The pump is programmed to switch on when there is any water movement so you will struggle to adapt to your preferred operation. Thanks. Technical Team.

Hi Brian, Use 22 mm pipework to and from the pump. The expansion pipe from the hot-water cylinder should always rise in order to prevent trapped air. The outlet pipework from the pump to the shower valve should rise, where possible, to prevent trapped air. Pipework from the pump to the shower valve should go up and over, rather than under floor. Do not fit any other outlets in the inlet pipes to the pump. See fig. 12. Use dedicated supplies to hot and cold water. Avoid blanked-off pipes. Avoid restrictions in the flexible hoses. Secure down all pipework to minimise noise and vibration. Thanks. Technical Team

Hello, Thank you for your question. This could be for a number of reason, most commonly caused by a build up in pressure on the hot water fed. I could possibly suggest contacting the manufacture on www.grundfos.com/uk or alternately our customer services team and we will contact them for you. info@victorianplumbing.co.uk Kind Regards.