A SP2B or a SP21S is an effective retrofit solution if your Combination Boiler suffers from flow and/or pressure problems.
The boiler cuts out either because the pressure drops below 10 metres head or the flow drops to below 2-3 litres a minute. Simply fit our pumps in15 minutes and your problem is solved. You can increase the pressure to combination boiler if you fit a SP21S Shower Power Booster on the cold pipe before a combination boiler by 0.4 to 0.6 bars. You can increase and protect the pressure flow from a combination boiler if you fit a SP2B Shower Power Booster on the hot pipe. Or you can do both.
Problems Solutions
Boiler Switching Off Because Of Low Pressure – Fit a SP21S before the boiler
Boiler Switching Off Due to Low Flow after the Boiler – Fit a SP2B after the boiler
Hot pressure fluctuates when another tap runs or just needs boosting – Fit a SP2B to protect the flow and pressure
Hot and Cold pressure fluctuates when another tap runs or just needs boosting – Fit a SP22S to protect the flow and pressure
Temperature & Pressure
Shower Power Boosters are designed for high temperatures and pressures and they are the only pump that cannot be hurt on the hot side of a Combi and cannot hurt a Combi.
Flow
The maximum effective flow of a SP2B gives up to 6 litres off water per shower (6 litres a minute is a “perfect shower”)
Protecting 2 showers with two SP2B gives a flow of 12 litres a minute.
UK Water Regulations stated that the maximum flow that can be boosted if you have a tankless system is12 litres a minute.
Competitors offer pumping solutions on the cold side of the Combi Boilers only (up to 12 litres a minute limit – limited by regulation )
Why it Works
Combi Boiler have a pressure sensor which cuts out when the pressure is too low and they can switch off if the flow is too low. They do this because if it were to heat just a small quantity of water it would ‘Kettle’ the water such that a small trickle of boiling water will be emitted. To avoid this a pressure sensor turns off the heating as soon as the pressure drops below the minimum pressure set by the manufacturer.
Dependant upon the model of combi boiler the pressure switch will be set at between 1.0 bars and 1.5 bars (8 metres head to 15 metres head). When a single SPB starts to pump it will create an additional head of 5 to 6 metres which may cause a combi boiler to start but as soon as the flow rate reaches 5 litres a minute the pressure added by a shower power booster will reduce to 3 or 4 metres head. If this occurs the boiler will run hot and cold in cycles. When a SP21S starts to pump they will create an additional head of 10 to 12 metres which reduces to an additional 6 metres head when the flow is 5 litres a minute. Since we are not responsible for the pressure switch in individual combi boilers and electric showers or the pressure you are starting with we can not predict if you need one or two SPB. We suggest that for most electric showers a single pump is adequate but for combi boilers which tend to have higher outputs the SP21S is the best starting point. You can boost showers or taps in your home up to the maximum capacity of your combi boiler. When others open taps in your home, provided you do not exceed the output of your boiler, the shower you are protecting will continue to flow strong and good.
SPB One Automatic & One Manual Water Pressure Pump
The WRight Choice micro booster cannot create hot water but it can take enough hot water to create the perfect shower. 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: 24KW Combi Boiler gives 11.5 Litres a minute (2 Showers) 30KW Combi Boiler gives 14.5 Litres a minute (2.4 Showers) 42KW Combi Boiler gives 20 Litres a minute (3 Showers)
Combi Boiler – Hot Water Boost The WRight Choice micro booster is the only pump on the market that can boost the pressure on the hot side of a combi boiler – you must not boost more than the maximum number of showers determined by your boiler. The WRight Choice micro booster cannot create hot water but it can take enough hot water to create the prefect shower. 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 the water is colder the output is less: 24KW Combi Boiler gives 11.5 Litres a minute (2 Showers) 30KW Combi Boiler gives 14.5 Litres a minute (2.4 Showers) 42KW Combi Boiler gives 20 Litres a minute (3 Showers) You can protect an boost showers or taps in your home up to the maximum capacity of your combi boiler. When others open taps in your home, provided you do not exceed the output of your boiler, the shower you protect will continue to flow strong and good.
This is explained in this video:-
Full installation details are provided in the Information Manual which you can download or read as a booklet delivered with the pumps.
Combi Boiler – Inlet Pressure Boost
COMBI BOILER WHOLE HOUSE SOLUTION
COMBI BOILER PROTECTED FLOW SOLUTION
A SP21S on the cold inlet of a combi boiler will help protect your boiler even if someone turns another tap on in your house or if your neighbours share a service to your house.
You can fit a SP21S before the boiler for a whole house boost AND separate SP2Bs to give additional protected flow and pressure to individual showers.
Maximun Flows
The maximum flow from a Combi Boiler is determined by its KW rating and in winter because the water is colder the output is less: 24KW Combi Boiler gives 11.5 Litres a minute – 2 Showers 30KW Combi Boiler gives 14.5 Litres a minute – 2.4 Showers 42KW Combi Boiler gives 20 Litres a minute – 3 Showers