Greenstar HIU Summer By Pass (Optional Accessory)
Greenstar HIU By Pass Bypass Valve : Summer by-pass that can be fitted within the HIU allowing district/centralised heat to the HIU before the heat meter. The benefits being a reduction in time for the customer when opening a hot tap within the property.
The by-pass function, sometimes called summer by-pass function or keep warm function, implements a feature to keep the supply side of the HIU hot. It is necessary to heat up the supply side pipe work after a long period of inactivity, this will minimise the time taken to produce hot water at the tap or radiator. This function is provided by a thermo-mechanical by-pass, this allows circulation of the district water at the appliance.
If a summer by-pass valve [see function schematic 9] is fitted; in stand-by mode, the district supply water flows from the district heating main, via the thermostatic by-pass valve, therefore ensuring that hot water at 45 °C - 50 °C is immediately available at the heat interface unit. This ensures a fast warm-up of hot water at the tap, often referred to as keep hot function.