A Trevi Boost is a cleaver way of boosting a gravity hot, taking pressure from a mains feed cold, and giving this to the hot.
Its a bit hit and miss as if your hot pressure is too low to start with or the mains pressure fluctuates, or the temperatures vary then your shower will suffer.
A ShowerPowerBooster works in harmony with your Trevi Boost and will always improve and stabilise your shower even if the cartridge is due for replacement. Leave your Trevi Boost in place and just fit a SPB – It always works.
What our customers say.

Trustpilot Review – M Taylor 14th February 2021
I have a pair of Trevi Boost showers which use cold water pressure to enhance the hot, they’re good but not that powerful. On one of Trevi’s troubleshooting sites an expert there suggested your power boosters to further power up the hot water. Following extensive viewing of Alan Wrights various videos, I decided to take the plunge! My plumber had never heard of the booster so I forwarded him the videos and he had no problem fitting the SP21S to all the hot water side. Wow, what a difference. Generally throughout the house very much improved flow, however the shower is a torrent! 6 litres-a-minute before to 17 litres-a-minute now. Thanks Alan, glad I took the plunge. Phil Cowell 14th Jan 2021