Boosting Pressure and Flows in Gravity Systems with Mains Pressure Cold
ShowerPowerBoosters are a great solution for anyone who has gravity hot and mains cold. If your cold is mains supply and your hot is gravity then we recommend you double boost the hot with a twin pack SP21S pump kit. A single ShowerPowerBooster SP2B on the hot will give a good shower but the SP21S will give a great shower with close to the equivalence of mains pressure on the hot.
For a very challenging kitchen tap or a downstairs shower a SP21S is the only solution. You can double boost the hot as there is no chance that this will imbalance the cold, so go for a SP21S.
The majority of mixers will balance differential pressures of 4 or even 5 to 1 so no problem. For some shower/tap mixers there is a requirement for balanced flow (similar pressures on hot and cold). If you have a shower mixer which needs balanced flow the high pressure cold restricts the low pressure hot, a SP2B (single boost) or a SP21S (double boost), will balance hot and cold pressures.
You can always try just the one pump and then upgrade but getting the job done in one hit is often favourite.
Before the pump starts the high cold pressure can hold the hot flow back. If the reduced flow on the hot falls below the 1.5 litres a minute needed to activate the flow switch and you may need to fit a pressure reducing valve on the cold only.
OUR PUMPS BOOST ANY AND ALL SYSTEMS SO VISIT OUR PLUMBERS FORUM FOR FOR FURTHER APPLICATIONS AND ADVICE (Click Here). For detailed advice specific to your home please contact our technical team on 01928 620 099 or email SPB@flowflex.com (out of hours email firstname.lastname@example.org )