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This blog describes the fitting of a micro pump cross link and how to operate the pump. Your pipework may differ from the example given but any cross link between the cold inlet pipe and the hot outlet pipe will create water circulation when that water is driven by our hot water tank booster. A trickle of cold water is taken from the bottom of the tank to the top of the tank where it is heated by the immersion heater. The heating of the water by the immersion heated is set at a rate greater or equal to the cooling effect of bringing in cold water. The top 1/3rd of the tank remains hot whilst the whole and for a typical 210 litre tank, heating the whole tank from cold will take 210 minutes (3.5 hours).
The hot water tank booster can be bought on this site here
How and why to create a heat store
Materials
1,2 Existing 22mm Pipe
3 22mm Single Check Valve
4,9 22mm x 15mm Tee
5 Hot Water Flow Booster
6 15mm Valve
7 15mm Elbow
8 15mm Pipe
Preparation Work – Vented Cylinders
Check you can isolate the header tank from the hot water cylinder. There is a 22mm pipe that connects the bottom of the header tank to the bottom of the hot water cylinder. If there is no isolation valve above where you need to install the cross link then you are best to install a lever valve first by draining the header tank. The best way to drain the header tank is to open a cold tap first and remove the final dregs by opening a hot tap.
Preparation Work – Unvented Cylinders
Closing the stop tap under the sink (Clockwise Close), should stop the flow. Check the shutoff by opening a hot tap – the flow should quickly stop.
22mm Single Check Valve
When the Hot Water Tank Booster first operates it takes cold water to the top of the tank through the 22mm pipe. Near the end of the heating period some hot water will leave the tank because there is no cold water. The 22mm single check valve is optional and its only function is to be a barrier to convection currents which could take warm water further towards the header tank.
Hot Water Tank Booster
This pump will not cavitate, burn out, it can last many years, it can resist extream pressures. Fitted to vented and unvented cylinders we expect many years of quiet efficient service.
15mm Valve
Close the valve fully (clockwise close).Crack the valve anticlockwise to open it just a bit. You are aiming for a flow rate of between 1.0 and 1.5 litres a minute but the precise flow rate is not critical.
How a Hot Water Tank Booster operates
(Fixed Rate Tariff)
The immersion heater is switched on at all times but despite being switched on it only draws power when a timer switches on the Hot Water Tank Booster.
How a Hot Water Tank Booster operates (Variable Rate Tariff)
The hot water tank booster is plugged into a Gruff Technology Smart Plug to optimise electricity consumption based on real-time tariff rates. This allows maximum storage on windy days.