With open circuit split systems the water is circulated from the tank at ground level through the solar collectors by an electric pump called a ‘circulator’. As the sun heats the water in the solar collectors, the increase in temperature activates the circulator. The circulator switches on whenever the water in the solar collectors is hotter than the water in the solar storage tank. The circulator moves the hotter water from the solar collectors through the solar hot pipe to the solar storage tank and the cooler water from the solar storage tank is circulated to the solar collectors via the solar cold pipe to be heated by the sun’s energy.

This process continues whilst solar energy is available and the water in the solar storage tank requires heating. The circulator will deactivate when the water temperature in the solar storage tank is around 70°C to 75°C.

The Solahart 272MLV split solar water heater is designed to be installed as an electric boosted solar water heater with its booster heating unit connected to a power supply, however it may be installed with an in-series continuous flow or storage booster. If installed with an in-series booster, then the electric booster heating unit will not be connected to a power supply.

As the sun heats the water in the solar collectors, the increase in temperature activates the circulator. The circulator switches on whenever the water in the solar collectors is hotter than the water in the solar storage tank. The circulator moves the hotter water from the solar collectors through the solar hot pipe to the solar storage tank and the cooler water from the solar storage tank is circulated to the solar collectors via the solar cold pipe to be heated by the sun’s energy.

This process continues whilst solar energy is available and the water in the solar storage tank requires heating. The circulator will deactivate when the water temperature in the solar storage tank is around 70°C to 75°C.

During normal operation if the amount of solar energy available reduces, such as when the sky becomes very cloudy or the sun becomes lower in the sky in the late afternoon, and the water no longer gains usable heat from the solar collectors, the circulator will deactivate. The water heater will then enter standby mode.

To help maximise system performance, solar collectors should be installed with an optimum orientation facing true north (in the southern hemisphere) or true south (in the northern hemisphere). Always check for true north or true south using a compass or other suitable device.

To help maximise system performance, solar collectors should be installed with an optimum inclination. This is equal to 90% to 100% of the local latitude angle when collectors are oriented within 60° of true north or true south, and between 10° and 20° if the collectors are oriented between 60° and 90° from the optimum orientation. Generally, improved summer performance is obtained from an angle of inclination less than the optimum angle and improved winter performance is obtained by an angle of inclination greater than the optimum angle. If the angle of inclination varies by 20° from the optimum angle, the solar collectors will receive about 10% less total annual solar radiation.