{"product_id":"vaillant-vdm-25-1-mixing-pump-group-kvs-8-0020191788","title":"Vaillant VDM 25 1\" Mixing Pump Group Kvs 8 | 0020191788","description":"\u003c!-- SEO Product Name: Vaillant VDM 25 1\" Mixing Pump Group Kvs 8 | 0020191788 | 95°C --\u003e\n\u003cdiv style=\"font-size:16px; max-width:900px; line-height:1.6; color:#1f2d2c;\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eVaillant VDM 25 1\" mixing pump group (0020191788)\u003c\/strong\u003e is a pre-assembled, insulated hydraulic module that supplies a \u003cstrong\u003emixed, lower-temperature heating circuit\u003c\/strong\u003e from a higher-temperature generator flow. It combines a \u003cstrong\u003ehigh-efficiency circulation pump (EEI \u0026lt; 0.23)\u003c\/strong\u003e, a \u003cstrong\u003ethree-way mixing valve with actuator (Rp 1, Kvs 8.0)\u003c\/strong\u003e and \u003cstrong\u003etwo ball shut-off valves with integrated thermometers\u003c\/strong\u003e, one of which includes a \u003cstrong\u003egravity brake\u003c\/strong\u003e, all inside a \u003cstrong\u003efitted insulation shell\u003c\/strong\u003e. Flow and return connections are \u003cstrong\u003eRp 1\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eIt is the right choice for circuits such as \u003cstrong\u003eunderfloor heating\u003c\/strong\u003e that need a lower flow temperature than the rest of the system. The group is rated for water temperatures up to \u003cstrong\u003e95 °C\u003c\/strong\u003e and operating pressure up to \u003cstrong\u003e6 bar\u003c\/strong\u003e, and the mixer and pump run from a \u003cstrong\u003e230 V \/ 50 Hz\u003c\/strong\u003e supply.\u003c\/p\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; gap:10px; margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003eRp 1\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003eFlow \u0026amp; return connections\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003eKvs 8.0\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003e3-way mixing valve, Rp 1\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003e95 °C\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003eMax water temperature\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003e6 bar\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003eMax operating pressure\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003e\u0026lt; 0.23\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003eEEI (high-efficiency pump)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:22px; font-weight:700;\"\u003e230 V\u003c\/div\u003e\n\u003cdiv style=\"font-size:13px;\"\u003e50 Hz mixer and pump\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#fff6e0; border-left:5px solid #b26a00; border-radius:6px; padding:12px 16px; margin:14px 0;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#b26a00; margin-bottom:4px;\"\u003eCheck the mixing valve size and flow\u003c\/div\u003e\n\u003cdiv style=\"line-height:1.5;\"\u003eThe mixing valve is rated \u003cstrong\u003eKvs 8.0\u003c\/strong\u003e (Rp 1), the largest in the Vaillant VDM range. Size it against your circuit's design flow rate and pressure drop. Smaller VDM groups with Rp ½ and Rp ¾ valves are available for lower flows, and an \u003cstrong\u003eunmixed\u003c\/strong\u003e group suits circuits running at generator flow temperature.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#fdeaea; border-left:5px solid #b3261e; border-radius:6px; padding:12px 16px; margin:14px 0;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#b3261e; margin-bottom:4px;\"\u003eInstallation \u0026amp; safety\u003c\/div\u003e\n\u003cdiv style=\"line-height:1.5;\"\u003eInstallation and electrical connection must be carried out by a competent heating engineer and electrician in line with the manufacturer's instructions and \u003cstrong\u003eBS 7671\u003c\/strong\u003e. Isolate the electrical supply before working on the pump or actuator, and allow the system to cool and depressurise before servicing.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2; border-left:5px solid #008377CF; border-radius:6px; padding:12px 16px; margin:14px 0;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:4px;\"\u003eProtects low-temperature circuits\u003c\/div\u003e\n\u003cdiv style=\"line-height:1.5;\"\u003eA mixing group lets \u003cstrong\u003eunderfloor heating and other low-temperature zones\u003c\/strong\u003e run at their own controlled flow temperature, alongside circuits at the full system temperature.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; gap:12px; margin:18px 0;\"\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eControlled mixed flow\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003e\n\u003cstrong\u003eThree-way mixing valve with actuator\u003c\/strong\u003e blends flow and return water to hold the circuit at its own temperature.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eHigh-efficiency pump\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003e\n\u003cstrong\u003eEEI below 0.23\u003c\/strong\u003e for low running costs and quiet, reliable circulation.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eIntegrated thermometers\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003e\n\u003cstrong\u003eBoth ball valves include a thermometer\u003c\/strong\u003e, giving instant flow and return readings for commissioning and servicing.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eGravity brake\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003e\n\u003cstrong\u003eOne ball valve incorporates a gravity brake\u003c\/strong\u003e to prevent unwanted gravity circulation when the pump is off.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eInsulation shell included\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003eA \u003cstrong\u003efitted insulation shell\u003c\/strong\u003e reduces heat loss and keeps the installation neat.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; border:1px solid #008377CF; border-top:4px solid #008377CF; border-radius:8px; padding:14px; background:#ffffff;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eRated to 95 °C \/ 6 bar\u003c\/div\u003e\n\u003cdiv style=\"font-size:15px; line-height:1.5;\"\u003eSuitable for \u003cstrong\u003ewater temperatures up to 95 °C\u003c\/strong\u003e and \u003cstrong\u003epressures up to 6 bar (0.6 MPa)\u003c\/strong\u003e.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #008377CF; border-radius:8px; overflow:hidden; margin:18px 0;\"\u003e\n\u003cdiv style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:10px 14px;\"\u003eSpecification\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eManufacturer\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eVaillant\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eManufacturer part number (MPN)\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e0020191788\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eGTIN \/ EAN\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e4024074730164\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eProduct type\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eMixing pump group (three-way mixer)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eFlow and return connections\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eRp 1\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMixing valve connection\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eRp 1\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMixing valve Kvs\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e8.0\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:10px 14px;\"\u003ePerformance \u0026amp; Electrical\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMaximum water temperature\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e95 °C\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMaximum operating pressure\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e6 bar (0.6 MPa)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eEnergy Efficiency Index (EEI)\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e\u0026lt; 0.23\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMixer and pump supply\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e230 V \/ 50 Hz\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:10px 14px;\"\u003eConstruction\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eCirculation pump\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eHigh-efficiency pump\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eMixing valve\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eThree-way mixer with actuator\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eShut-off valves\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e2 ball valves with integrated thermometers\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eGravity brake\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eFitted in one of the two ball valves\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#f2f9f8; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eInsulation\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003eInsulation shell included\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; background:#ffffff; padding:9px 14px; border-bottom:1px solid #dfeeed;\"\u003e\n\u003cdiv style=\"flex:1 1 200px; font-weight:700;\"\u003eDimensions (approx.)\u003c\/div\u003e\n\u003cdiv style=\"flex:2 1 260px;\"\u003e250 mm wide × 355 mm high\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin:22px 0 8px 0; font-weight:700; color:#008377CF; font-size:18px;\"\u003eFrequently asked questions\u003c\/div\u003e\n\u003cdetails style=\"border:1px solid #008377CF; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:11px 14px; cursor:pointer;\"\u003eDoes this pump group include a mixing valve?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 14px; line-height:1.55;\"\u003eYes. The VDM 25 (0020191788) includes a \u003cstrong\u003ethree-way mixing valve with actuator\u003c\/strong\u003e (Rp 1, Kvs 8.0), so it can supply a mixed, lower-temperature circuit.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #008377CF; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:11px 14px; cursor:pointer;\"\u003eWhat are the connection sizes?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 14px; line-height:1.55;\"\u003e\n\u003cstrong\u003eRp 1\u003c\/strong\u003e for the flow and return connections, and \u003cstrong\u003eRp 1\u003c\/strong\u003e for the mixing valve.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #008377CF; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:11px 14px; cursor:pointer;\"\u003eWhat temperature and pressure is it rated for?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 14px; line-height:1.55;\"\u003e\n\u003cstrong\u003eUp to 95 °C\u003c\/strong\u003e water temperature and \u003cstrong\u003eup to 6 bar (0.6 MPa)\u003c\/strong\u003e operating pressure.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #008377CF; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:11px 14px; cursor:pointer;\"\u003eWhat electrical supply does it need?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 14px; line-height:1.55;\"\u003eThe mixer and circulation pump run from a \u003cstrong\u003e230 V \/ 50 Hz\u003c\/strong\u003e supply. Wiring should be done by a qualified electrician in accordance with BS 7671.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails style=\"border:1px solid #008377CF; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:11px 14px; cursor:pointer;\"\u003eIs the insulation included?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 14px; line-height:1.55;\"\u003eYes. A \u003cstrong\u003efitted insulation shell\u003c\/strong\u003e is part of the pump group.\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e","brand":"Vaillant","offers":[{"title":"Default Title","offer_id":67763443990918,"sku":"20191788","price":695.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/VaillantVDM15.5inchmixingpumpgroupwithmixer.jpg?v=1792677214","url":"https:\/\/qualityheating.co.uk\/products\/vaillant-vdm-25-1-mixing-pump-group-kvs-8-0020191788","provider":"AIZO Quality Heating","version":"1.0","type":"link"}