{"product_id":"worcester-greenstar-boiler-expansion-vessel-7l-8716122434","title":"Worcester Greenstar Boiler Expansion Vessel 7L 8716122434","description":"\u003ch1\u003e\u003cspan\u003eWorcester Greenstar Boiler Expansion Vessel 7L 8716122434\u003c\/span\u003e\u003c\/h1\u003e\n\u003ch2\u003e\u003cspan\u003eProduct Overview\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eWorcester Greenstar Boiler Expansion Vessel (Part Number: 8716122434)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e is a 7-litre pressure management component designed for use within selected Worcester Bosch Greenstar heating systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePart number \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e8716122434\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e is identified as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e7-Litre Expansion Vessel\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe expansion vessel forms part of the boiler's sealed central heating circuit. It accommodates the expansion of heating water as its temperature increases, helping to maintain stable system pressure during normal operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eℹ️ \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eProduct Condition:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis product may be available in \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eNew or Refurbished\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e condition. Please select the required option when ordering.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eTechnical Insight \u0026amp; Common Failure Symptoms\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe expansion vessel is a pressure management component within a sealed heating system. It contains a flexible diaphragm that separates the heating water from a pressurised gas chamber.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAs the heating water expands during operation, the vessel accommodates the increased water volume, helping to prevent excessive pressure increases.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOver time, expansion vessel performance may be affected by loss of pre-charge pressure, diaphragm deterioration or internal damage.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePossible symptoms that may require investigation of the expansion vessel or associated components include:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eBoiler pressure rising excessively when heating is operating\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eSystem pressure dropping after the heating cools\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eFrequent need to repressurise the heating system\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eWater discharging from the pressure relief valve\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eSignificant pressure fluctuations between hot and cold operation\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eLoss of expansion vessel pre-charge pressure\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eLeakage or damage around the expansion vessel\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eThese symptoms do \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003enot necessarily confirm a faulty expansion vessel\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, as similar issues may be caused by leaks, pressure relief valve faults, incorrect system filling pressure or other heating system components. Correct professional diagnosis should be carried out before replacement.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eSafety Advice\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan\u003eBoiler expansion vessels and associated pressurised heating components should only be inspected, removed or installed by a \u003c\/span\u003e\u003c\/em\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan\u003esuitably qualified and competent heating engineer\u003c\/span\u003e\u003c\/em\u003e\u003c\/strong\u003e\u003cem\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/em\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan\u003eAlways isolate the appliance and allow the heating system to cool before carrying out any work. The system must be safely depressurised in accordance with the manufacturer's servicing instructions. The expansion vessel pre-charge pressure, system filling pressure and all relevant connections must be checked, and appropriate leakage and operational safety tests completed before the boiler is returned to service.\u003c\/span\u003e\u003c\/em\u003e\u003c\/p\u003e","brand":"Worcecster","offers":[{"title":"New \/ Genuine","offer_id":50437697962087,"sku":"N9577","price":90.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0615\/0923\/8887\/files\/1013108.jpg?v=1791878421","url":"https:\/\/nationalboilerspares.co.uk\/products\/worcester-greenstar-boiler-expansion-vessel-7l-8716122434","provider":"National Boiler Spares","version":"1.0","type":"link"}