A SP21S double boost on the cold inlet of a Combi Boiler will help protect your boiler, even if someone turns another tap on in your house or your neighbours share a service to your house.
Combi Boilers are designed to switch off if the pressure falls, so if you are in a house and someone turns on a tap you might just end up with your hot shower becoming a cold shower. To maximise the benefit of the pressure boost, we normally recommend a double boost, and a second pump can be bought for less than half the cost of the first pump.
Protect the pressure to your Combi Boiler with a WRightChoice Micro-Booster
A good shower needs enough water to wash away the suds and enough pressure to give a nice forceful spray pattern. We aim to give 6 litres a minute and a minimum of 3 metres head to achieve this.
The maximum flow from a Combi Boiler is determined by its KW rating, and in winter, because water is colder, the output is less:
24 KW Combi Boiler gives 11.5 litres a minute (2 showers)
30 KW Combi Boiler gives 14.5 litres a minute (2.4 showers)
42 KW Combi Boiler gives 20.0 litres a minute (3 showers)
You can stop your boiler cutting out and boost a single shower or tap in your home up to the maximum capacity of your micro booster. When others open taps in your home, provided you do not exceed the output of our micro booster (6 litres a minute), the Combi Boiler will continue to heat this water.