{"product_id":"vaillant-solar-discharge-vessel-0020145563","title":"Vaillant Solar Discharge Vessel 0020145563","description":"\u003cdiv style=\"font-size:16px;font-family:Arial,Helvetica,sans-serif;color:#222;max-width:900px;margin:0 auto;line-height:1.6;\"\u003e\n\n  \u003c!-- INTRO --\u003e\n  \u003cp\u003eThe \u003cstrong\u003eVaillant Solar Discharge Vessel\u003c\/strong\u003e (article number 0020145563) is a \u003cstrong\u003ecompact, wall-mounted glycol collection vessel\u003c\/strong\u003e designed for use with Vaillant aroTHERM heat pump systems. Its purpose is straightforward but essential: when a heat pump system's \u003cstrong\u003ePressure Relief Valve (PRV) opens\u003c\/strong\u003e, glycol-based antifreeze is discharged from the sealed heating circuit. Without a dedicated collection vessel, this glycol would enter the drainage system — which is environmentally unacceptable and, in most cases, contrary to water regulations.\u003c\/p\u003e\n  \u003cp\u003eThe Vaillant Solar Discharge Vessel \u003cstrong\u003esafely captures and retains this glycol discharge\u003c\/strong\u003e, protecting the drainage system and allowing the installer or homeowner to inspect the volume of discharge — a useful indicator of system health. With a \u003cstrong\u003e9.7 L usable capacity\u003c\/strong\u003e and a slim wall-mounted profile, it fits neatly in the plant room alongside the heat pump. Where a larger collection capacity is required, \u003cstrong\u003emultiple vessels can be connected vertically in series\u003c\/strong\u003e. Supplied complete with \u003cstrong\u003e2 screws and 2 wall plugs\u003c\/strong\u003e, installation is straightforward.\u003c\/p\u003e\n\n  \u003c!-- STAT STRIP --\u003e\n  \u003cdiv style=\"display:flex;flex-wrap:wrap;gap:12px;margin:24px 0;\"\u003e\n    \u003cdiv style=\"flex:1;min-width:130px;background:#008377CF;color:#fff;border-radius:8px;padding:16px 12px;text-align:center;\"\u003e\n      \u003cdiv style=\"font-size:26px;font-weight:700;\"\u003e9.7 L\u003c\/div\u003e\n      \u003cdiv style=\"font-size:13px;margin-top:4px;\"\u003eCollection Capacity\u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:130px;background:#008377CF;color:#fff;border-radius:8px;padding:16px 12px;text-align:center;\"\u003e\n      \u003cdiv style=\"font-size:26px;font-weight:700;\"\u003e1.04 kg\u003c\/div\u003e\n      \u003cdiv style=\"font-size:13px;margin-top:4px;\"\u003eNet Weight\u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:130px;background:#008377CF;color:#fff;border-radius:8px;padding:16px 12px;text-align:center;\"\u003e\n      \u003cdiv style=\"font-size:26px;font-weight:700;\"\u003eWall\u003c\/div\u003e\n      \u003cdiv style=\"font-size:13px;margin-top:4px;\"\u003eMounted — fixings included\u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"flex:1;min-width:130px;background:#008377CF;color:#fff;border-radius:8px;padding:16px 12px;text-align:center;\"\u003e\n      \u003cdiv style=\"font-size:26px;font-weight:700;\"\u003eSeries\u003c\/div\u003e\n      \u003cdiv style=\"font-size:13px;margin-top:4px;\"\u003eFit vertically for greater capacity\u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- CALLOUT: AMBER — COMPATIBILITY --\u003e\n  \u003cdiv style=\"background:#fffbea;border-left:5px solid #e6a817;padding:14px 18px;border-radius:6px;margin:20px 0;\"\u003e\n    \u003cstrong style=\"color:#b37d00;\"\u003e⚠ Compatibility Note\u003c\/strong\u003e\u003cbr\u003e\n    This discharge vessel is \u003cstrong\u003especified as an accessory for Vaillant aroTHERM plus and aroTHERM split air-source heat pump systems\u003c\/strong\u003e. It is listed in the Vaillant aroTHERM plus Installer's Quick Guide as the designated discharge vessel for these systems. Always confirm compatibility with the specific system design with reference to the relevant Vaillant installation documentation before fitting. Installation should be carried out by a competent, qualified heating engineer.\n  \u003c\/div\u003e\n\n  \u003c!-- CALLOUT: TEAL — PRV EXPLANATION --\u003e\n  \u003cdiv style=\"background:#e6f4f3;border-left:5px solid #008377CF;padding:14px 18px;border-radius:6px;margin:20px 0;\"\u003e\n    \u003cstrong style=\"color:#005c54;\"\u003eℹ Why a Discharge Vessel Is Needed\u003c\/strong\u003e\u003cbr\u003e\n    Vaillant aroTHERM heat pump systems use a \u003cstrong\u003eglycol-based antifreeze mix\u003c\/strong\u003e in the sealed heating circuit to prevent freezing in low ambient temperatures. Heat pump circuits are sealed and pressurised; if system pressure exceeds the PRV setting, the valve opens and releases fluid. Because \u003cstrong\u003eglycol must not be discharged into surface water drainage\u003c\/strong\u003e (it is harmful to aquatic life and regulated under environmental legislation), a dedicated discharge vessel is required to capture and contain it safely. The collected glycol can then be disposed of correctly or the cause of the pressure rise investigated.\n  \u003c\/div\u003e\n\n  \u003c!-- FEATURES GRID --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;padding:10px 16px;border-radius:6px 6px 0 0;font-weight:700;font-size:16px;margin-top:28px;\"\u003eKey Features \u0026amp; Benefits\u003c\/div\u003e\n  \u003cdiv style=\"display:flex;flex-wrap:wrap;gap:14px;padding:16px 0;\"\u003e\n\n    \u003cdiv style=\"flex:1;min-width:260px;background:#f0faf9;border:1px solid #c8e6e3;border-radius:8px;padding:18px;\"\u003e\n      \u003cdiv style=\"font-weight:700;font-size:15px;border-bottom:2px solid #008377CF;padding-bottom:6px;margin-bottom:10px;\"\u003eGlycol Capture — Protects Drainage Systems\u003c\/div\u003e\n      \u003cp style=\"margin:0;\"\u003eWhen the system PRV opens, the discharge vessel \u003cstrong\u003esafely collects and retains the released glycol antifreeze\u003c\/strong\u003e, preventing it from entering surface water drains or watercourses. This protects the environment, keeps the system compliant with water regulations, and allows the collected discharge to be inspected and disposed of correctly.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"flex:1;min-width:260px;background:#f0faf9;border:1px solid #c8e6e3;border-radius:8px;padding:18px;\"\u003e\n      \u003cdiv style=\"font-weight:700;font-size:15px;border-bottom:2px solid #008377CF;padding-bottom:6px;margin-bottom:10px;\"\u003e9.7 L Capacity — Wall-Mounted Profile\u003c\/div\u003e\n      \u003cp style=\"margin:0;\"\u003eThe vessel offers a \u003cstrong\u003e9.7 L collection capacity\u003c\/strong\u003e in a compact, wall-mounted body measuring just 305 × 393 × 153 mm. The slim profile minimises the space required in the plant room and sits neatly alongside aroTHERM indoor components. \u003cstrong\u003eTwo screws and two wall plugs are supplied\u003c\/strong\u003e for straightforward secure wall fixing.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"flex:1;min-width:260px;background:#f0faf9;border:1px solid #c8e6e3;border-radius:8px;padding:18px;\"\u003e\n      \u003cdiv style=\"font-weight:700;font-size:15px;border-bottom:2px solid #008377CF;padding-bottom:6px;margin-bottom:10px;\"\u003eExpandable — Vertical Series Connection\u003c\/div\u003e\n      \u003cp style=\"margin:0;\"\u003eWhere system design requires a \u003cstrong\u003elarger total collection capacity\u003c\/strong\u003e, multiple vessels can be \u003cstrong\u003econnected vertically in series\u003c\/strong\u003e. This provides flexibility for larger aroTHERM installations or systems with higher glycol volumes, without needing a single oversized vessel.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv style=\"flex:1;min-width:260px;background:#f0faf9;border:1px solid #c8e6e3;border-radius:8px;padding:18px;\"\u003e\n      \u003cdiv style=\"font-weight:700;font-size:15px;border-bottom:2px solid #008377CF;padding-bottom:6px;margin-bottom:10px;\"\u003eGenuine Vaillant Accessory\u003c\/div\u003e\n      \u003cp style=\"margin:0;\"\u003eSupplied by Vaillant and \u003cstrong\u003elisted in the official aroTHERM plus Installer's Quick Guide\u003c\/strong\u003e as the designated discharge vessel for these systems. Using a genuine Vaillant accessory ensures correct compatibility and fit, supports system warranty, and confirms the installation meets Vaillant's own design and commissioning standards.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n  \u003c\/div\u003e\n\n  \u003c!-- SPEC TABLE --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;padding:10px 16px;border-radius:6px 6px 0 0;font-weight:700;font-size:16px;margin-top:28px;\"\u003eTechnical Specifications\u003c\/div\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;font-size:14px;\"\u003e\n    \u003ctbody\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;width:45%;\"\u003eVaillant Article Number (MPN)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e0020145563 (also referenced as 20145563)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eEAN\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e4024074649695\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eCollection Capacity\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e9.7 litres\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eWidth (mm)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e305\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eDepth (mm)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e393\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eHeight (mm)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e153\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eNet Weight (kg)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e1.04\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eGross Weight inc. Packaging (kg)\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003e1.24\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eMounting\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003eWall-mounted (vertical)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eSeries Fitting\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003eYes — multiple vessels can be connected vertically in series\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eSupplied With\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003eSolar discharge vessel, 2 × screws, 2 × wall plugs\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#fff;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eCompatible Systems\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003eVaillant aroTHERM plus, aroTHERM split air-source heat pump systems\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"background:#f0faf9;\"\u003e\n        \u003ctd style=\"padding:9px 14px;font-weight:700;\"\u003eFunction\u003c\/td\u003e\n        \u003ctd style=\"padding:9px 14px;\"\u003eCollects heating system glycol on PRV opening — prevents glycol discharge into drainage\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003c!-- FAQ --\u003e\n  \u003cdiv style=\"background:#008377CF;color:#fff;padding:10px 16px;border-radius:6px 6px 0 0;font-weight:700;font-size:16px;margin-top:28px;\"\u003eFrequently Asked Questions\u003c\/div\u003e\n\n  \u003cdetails style=\"border:1px solid #c8e6e3;border-top:none;padding:14px 16px;background:#fff;\"\u003e\n    \u003csummary style=\"font-weight:700;cursor:pointer;color:#005c54;\"\u003eWhat is the Vaillant Solar Discharge Vessel used for?\u003c\/summary\u003e\n    \u003cp style=\"margin:10px 0 0;\"\u003eThe vessel is designed to \u003cstrong\u003ecollect glycol antifreeze discharged from a Vaillant aroTHERM heat pump system's Pressure Relief Valve (PRV)\u003c\/strong\u003e when the PRV opens. Because glycol must not enter the surface water drainage system — it is environmentally regulated — this vessel captures the discharged fluid safely. The collected glycol can then be inspected (to help diagnose why the PRV opened) and disposed of responsibly.\u003c\/p\u003e\n  \u003c\/details\u003e\n\n  \u003cdetails style=\"border:1px solid #c8e6e3;border-top:none;padding:14px 16px;background:#f0faf9;\"\u003e\n    \u003csummary style=\"font-weight:700;cursor:pointer;color:#005c54;\"\u003eIs this vessel mandatory for an aroTHERM heat pump installation?\u003c\/summary\u003e\n    \u003cp style=\"margin:10px 0 0;\"\u003eYes, in practice. Vaillant \u003cstrong\u003elists the discharge vessel (0020145563) in the official aroTHERM plus Installer's Quick Guide\u003c\/strong\u003e as the designated accessory for managing PRV discharge from glycol-filled systems. Environmental regulations in the UK restrict glycol from entering surface water drains, making a collection vessel a practical and regulatory requirement in aroTHERM heat pump installations.\u003c\/p\u003e\n  \u003c\/details\u003e\n\n  \u003cdetails style=\"border:1px solid #c8e6e3;border-top:none;padding:14px 16px;background:#fff;\"\u003e\n    \u003csummary style=\"font-weight:700;cursor:pointer;color:#005c54;\"\u003eCan the 9.7 L capacity be increased?\u003c\/summary\u003e\n    \u003cp style=\"margin:10px 0 0;\"\u003eYes. Where a larger collection capacity is required, \u003cstrong\u003emultiple vessels can be connected vertically in series\u003c\/strong\u003e. This allows installers to size the total discharge capacity to match the glycol volume in the system, without requiring a single large vessel. The slim wall-mounted profile of each unit makes series fitting practical in most plant room configurations.\u003c\/p\u003e\n  \u003c\/details\u003e\n\n  \u003cdetails style=\"border:1px solid #c8e6e3;border-top:none;padding:14px 16px;background:#f0faf9;\"\u003e\n    \u003csummary style=\"font-weight:700;cursor:pointer;color:#005c54;\"\u003eWhy does an aroTHERM heat pump use glycol rather than plain water?\u003c\/summary\u003e\n    \u003cp style=\"margin:10px 0 0;\"\u003eVaillant aroTHERM heat pumps use a \u003cstrong\u003eglycol-based antifreeze solution in their sealed heating circuit\u003c\/strong\u003e to prevent the system water from freezing during cold weather operation — including during defrost cycles when the heat pump is actively managing ice formation on the outdoor unit. Glycol also provides corrosion inhibition in the sealed circuit. This is standard practice for air-source heat pump systems operating in UK climates.\u003c\/p\u003e\n  \u003c\/details\u003e\n\n  \u003cdetails style=\"border:1px solid #c8e6e3;border-top:none;padding:14px 16px;background:#fff;border-radius:0 0 6px 6px;\"\u003e\n    \u003csummary style=\"font-weight:700;cursor:pointer;color:#005c54;\"\u003eWhy is glycol not permitted to enter the drainage system?\u003c\/summary\u003e\n    \u003cp style=\"margin:10px 0 0;\"\u003eEthylene glycol and propylene glycol — both used as antifreeze in heating systems — are \u003cstrong\u003eharmful to aquatic life\u003c\/strong\u003e if discharged into watercourses, and their disposal into surface water drains is restricted under UK environmental regulations. Heating glycol also typically contains corrosion inhibitors which add further regulated substances. A discharge vessel ensures all released glycol is captured for proper disposal, keeping the installation compliant with both water regulations and environmental legislation.\u003c\/p\u003e\n  \u003c\/details\u003e\n\n\u003c\/div\u003e","brand":"Vaillant","offers":[{"title":"Default Title","offer_id":64702110695773,"sku":"20145563","price":89.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/VaillantSolarDischargeVessel.png?v=1778847443","url":"https:\/\/qualityheating.co.uk\/products\/vaillant-solar-discharge-vessel-0020145563","provider":"AIZO Quality Heating","version":"1.0","type":"link"}