{"product_id":"polypipe-zonal-regulation-unit-2-3-circuit-zru-complete-with-manifold","title":"Polypipe Zonal Regulation Unit 2\/3 Circuit ZRU Complete with Manifold","description":"\u003cstyle\u003e\n\/* ── Reset \u0026 Base ────────────────────────────────────────────────────── *\/\n.qh-pd, .qh-pd *::before, .qh-pd *::after { box-sizing: border-box; margin: 0; padding: 0; }\n.qh-pd { font-family: inherit; font-size: 16px; line-height: 1.65; color: #1a1a1a; }\n\n\/* ── Brand colour tokens ─────────────────────────────────────────────── *\/\n\/* Primary:   #008377  (Polypipe teal — fully opaque version of #008377CF) *\/\n\/* Dark:      #005f55  (darker teal for hover \/ header backgrounds)         *\/\n\/* Light bg:  #e6f4f3  (very light teal wash)                               *\/\n\/* Accent:    #f4a921  (warm amber — contrasts teal cleanly)                *\/\n\n\/* ── Badges ─────────────────────────────────────────────────────────── *\/\n.qh-pd .badge-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 1.25rem; }\n.qh-pd .badge { display: inline-block; font-size: 11px; font-weight: 700; border-radius: 4px; padding: 3px 10px; letter-spacing: 0.05em; text-transform: uppercase; }\n.qh-pd .b-teal   { background: #008377; color: #fff; }\n.qh-pd .b-dark   { background: #005f55; color: #fff; }\n.qh-pd .b-amber  { background: #f4a921; color: #1a1a1a; }\n.qh-pd .b-grey   { background: #555;    color: #fff; }\n.qh-pd .b-blue   { background: #1565c0; color: #fff; }\n.qh-pd .b-outline { background: transparent; color: #008377; border: 1.5px solid #008377; }\n\n\/* ── Section label ───────────────────────────────────────────────────── *\/\n.qh-pd .section-label {\n  font-size: 10.5px; font-weight: 800; letter-spacing: 0.14em; text-transform: uppercase;\n  color: #008377; margin-bottom: 0.55rem; margin-top: 1.7rem;\n  padding-bottom: 4px; border-bottom: 2px solid #008377;\n}\n\n\/* ── Intro text ──────────────────────────────────────────────────────── *\/\n.qh-pd .prod-desc { font-size: 15.5px; color: #2a2a2a; margin-bottom: 1.4rem; line-height: 1.8; }\n\n\/* ── Feature list ────────────────────────────────────────────────────── *\/\n.qh-pd .feat-list { list-style: none; margin-bottom: 1.4rem; padding: 0; }\n.qh-pd .feat-list li { padding: 4px 0 4px 22px; position: relative; font-size: 15px; color: #1a1a1a; }\n.qh-pd .feat-list li::before { content: \"✓\"; position: absolute; left: 0; color: #008377; font-weight: 800; font-size: 15px; }\n\n\/* ── Spec \/ detail table ─────────────────────────────────────────────── *\/\n.qh-pd .spec-table { width: 100%; border-collapse: collapse; margin-bottom: 1.5rem; font-size: 14px; }\n.qh-pd .spec-table td { padding: 8px 12px; border-bottom: 1px solid #d4eeeb; vertical-align: top; }\n.qh-pd .spec-table tr:nth-child(even) td { background: #e6f4f3; }\n.qh-pd .spec-table tr:nth-child(odd) td  { background: #fff; }\n.qh-pd .spec-table td:first-child { font-weight: 700; color: #005f55; width: 40%; }\n.qh-pd .sku { font-family: 'Courier New', monospace; font-size: 12px; background: #e6f4f3; color: #005f55; padding: 2px 6px; border-radius: 3px; font-weight: 700; }\n\n\/* ── Callouts ────────────────────────────────────────────────────────── *\/\n.qh-pd .callout { padding: 0.85rem 1.15rem; border-radius: 0 6px 6px 0; margin: 0.9rem 0; font-size: 14.5px; line-height: 1.7; }\n.qh-pd .callout-teal  { background: #e6f4f3; border-left: 4px solid #008377; color: #00443d; }\n.qh-pd .callout-amber { background: #fef8ec; border-left: 4px solid #f4a921; color: #4a3000; }\n.qh-pd .callout-warn  { background: #fff3e0; border-left: 4px solid #e65100; color: #4a1800; }\n.qh-pd .callout-blue  { background: #e8f4fd; border-left: 4px solid #1565c0; color: #0a2a50; }\n\n\/* ── Installation steps ──────────────────────────────────────────────── *\/\n.qh-pd .steps { list-style: none; padding: 0; margin-bottom: 1.4rem; counter-reset: step; }\n.qh-pd .steps li {\n  counter-increment: step;\n  display: flex; align-items: flex-start; gap: 0.85rem;\n  padding: 0.75rem; border-radius: 6px;\n  margin-bottom: 0.5rem; font-size: 14.5px; line-height: 1.7;\n  background: #fff; border: 1px solid #d4eeeb;\n}\n.qh-pd .steps li::before {\n  content: counter(step);\n  display: flex; align-items: center; justify-content: center;\n  flex: 0 0 28px; width: 28px; height: 28px; min-width: 28px;\n  border-radius: 50%;\n  background: #008377; color: #fff;\n  font-size: 13px; font-weight: 800; line-height: 1;\n  margin-top: 3px;\n}\n.qh-pd .steps li strong { color: #005f55; }\n\n\/* ── FAQ ─────────────────────────────────────────────────────────────── *\/\n.qh-pd .faq-item { border-bottom: 1px solid #d4eeeb; padding: 0.85rem 0; }\n.qh-pd .faq-item:last-child { border-bottom: none; }\n.qh-pd .faq-q {\n  font-size: 14.5px; font-weight: 700; color: #005f55;\n  padding-left: 1.4rem; position: relative; cursor: default;\n}\n.qh-pd .faq-q::before { content: \"Q\"; position: absolute; left: 0; color: #008377; font-weight: 900; }\n.qh-pd .faq-a { font-size: 14px; color: #2a2a2a; margin-top: 0.4rem; padding-left: 1.4rem; line-height: 1.7; }\n\n\/* ── What's in the box ───────────────────────────────────────────────── *\/\n.qh-pd .box-grid {\n  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));\n  gap: 0.6rem; margin-bottom: 1.4rem;\n}\n.qh-pd .box-item {\n  background: #e6f4f3; border: 1px solid #b2dcd8; border-radius: 6px;\n  padding: 0.6rem 0.75rem; font-size: 13.5px; color: #00443d;\n  display: flex; align-items: flex-start; gap: 0.4rem;\n}\n.qh-pd .box-item::before { content: \"✔\"; color: #008377; font-weight: 900; flex-shrink: 0; margin-top: 1px; }\n\n\/* ── Compatibility strip ─────────────────────────────────────────────── *\/\n.qh-pd .compat-strip {\n  background: #005f55; color: #fff; border-radius: 6px;\n  padding: 0.8rem 1.1rem; font-size: 14px; margin-bottom: 1.4rem; line-height: 1.7;\n}\n.qh-pd .compat-strip strong { color: #7fe8df; }\n\u003c\/style\u003e\n\n\u003cdiv class=\"qh-pd\"\u003e\n\n  \u003c!-- ── Badges ── --\u003e\n  \u003cdiv class=\"badge-row\"\u003e\n    \u003cspan class=\"badge b-teal\"\u003eUnderfloor Heating\u003c\/span\u003e\n    \u003cspan class=\"badge b-dark\"\u003eSingle Room \/ Extension\u003c\/span\u003e\n    \u003cspan class=\"badge b-teal\"\u003eUp to 30 m²\u003c\/span\u003e\n    \u003cspan class=\"badge b-amber\"\u003e2 or 3 Circuits\u003c\/span\u003e\n    \u003cspan class=\"badge b-dark\"\u003eBuilt-in Pump \u0026amp; Mixing Valve\u003c\/span\u003e\n    \u003cspan class=\"badge b-grey\"\u003eDomestic \u0026amp; Commercial\u003c\/span\u003e\n    \u003cspan class=\"badge b-outline\"\u003ePolypipe UFH\u003c\/span\u003e\n  \u003c\/div\u003e\n\n  \u003c!-- ── Introduction ── --\u003e\n  \u003cp class=\"prod-desc\"\u003e\n    The Polypipe Zonal Regulation Unit (ZRU) is a complete, self-contained underfloor heating control unit that allows a single room or extension of up to 30 m² to be connected to an existing wet central heating system — with no costly hydraulic alterations, no new wiring centres, and no changes to the existing boiler or radiator circuits. It bridges the temperature gap between a radiator system (typically 70–80°C flow) and the lower temperatures required for underfloor heating (30–55°C) using a built-in thermostatic blending valve. A dedicated pump within the unit provides the correct flow rate for the UFH loops independently of the existing system pump. The PB970028 variant includes a built-in 2-circuit manifold as standard; a third circuit can be formed by adding two 15mm spigot elbows and two 15mm tees (sold separately).\n  \u003c\/p\u003e\n\n  \u003c!-- ── Key features ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eKey Features\u003c\/div\u003e\n  \u003cul class=\"feat-list\"\u003e\n    \u003cli\u003eConnects single rooms or extensions up to 30 m² to any existing 2-pipe wet heating system\u003c\/li\u003e\n    \u003cli\u003eNo hydraulic or electrical alterations to the existing heating system required\u003c\/li\u003e\n    \u003cli\u003eBuilt-in thermostatic blending valve blends flow water to the correct UFH temperature (30–60°C)\u003c\/li\u003e\n    \u003cli\u003eDedicated integral pump boosts flow — UFH loops are not dependent on the existing system pump\u003c\/li\u003e\n    \u003cli\u003eBuilt-in pipe thermostat senses available heat — pump only runs when boiler water exceeds 45°C\u003c\/li\u003e\n    \u003cli\u003eOptional volt-free room thermostat or wireless sensor connection for precise air temperature control\u003c\/li\u003e\n    \u003cli\u003e2-circuit manifold built in as standard — expandable to 3 circuits with standard 15mm fittings\u003c\/li\u003e\n    \u003cli\u003eCan operate the UFH zone independently of the rest of the heating system when used with a zone valve\u003c\/li\u003e\n    \u003cli\u003eAlso suitable for low surface temperature (LST) radiator applications where water temperature control is needed\u003c\/li\u003e\n    \u003cli\u003eWall-mounted in the heated room or positioned elsewhere in the property — fully flexible siting\u003c\/li\u003e\n    \u003cli\u003eSuitable for domestic and commercial buildings\u003c\/li\u003e\n    \u003cli\u003eCompatible with all Polypipe UFH systems: Overlay™, Overlay™ Lite, MHP, solid screeded floors, and more\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003c!-- ── What's in the box ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eWhat's Included\u003c\/div\u003e\n  \u003cdiv class=\"box-grid\"\u003e\n    \u003cdiv class=\"box-item\"\u003eZonal Regulation Unit body (pump, blending valve, pipe stat)\u003c\/div\u003e\n    \u003cdiv class=\"box-item\"\u003e2-circuit built-in manifold (flow \u0026amp; return)\u003c\/div\u003e\n    \u003cdiv class=\"box-item\"\u003eWiring module with terminal block\u003c\/div\u003e\n    \u003cdiv class=\"box-item\"\u003eWall fixing template \u0026amp; screws\u003c\/div\u003e\n    \u003cdiv class=\"box-item\"\u003eFixing plugs\u003c\/div\u003e\n    \u003cdiv class=\"box-item\"\u003eInstallation guide\u003c\/div\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"callout callout-teal\"\u003e\n    ℹ️ \u003cstrong\u003e3rd circuit upgrade:\u003c\/strong\u003e To form a third heating circuit, add 2 × 15mm spigot elbows and 2 × 15mm tees to the ZRU manifold ports. These standard Polypipe PolyPlumb fittings are sold separately.\n  \u003c\/div\u003e\n\n  \u003c!-- ── How it works ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eHow the ZRU Works\u003c\/div\u003e\n  \u003cp style=\"font-size:14.5px; color:#2a2a2a; margin-bottom:0.8rem; line-height:1.75;\"\u003e\n    The ZRU forms a low-loss header between the existing heating circuit and the UFH loops, managing temperature and flow automatically. The six-step operational sequence is:\n  \u003c\/p\u003e\n  \u003col class=\"steps\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBoiler fires:\u003c\/strong\u003e Heating water circulates from the boiler through the existing system pipework and enters the ZRU via the Heating Flow connection.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePipe thermostat activates:\u003c\/strong\u003e The built-in pipe thermostat senses that heating water is available (≥45°C) and sends a live signal to the ZRU pump.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRoom thermostat calls for heat:\u003c\/strong\u003e If a room thermostat is fitted and the room temperature is below setpoint, the pump starts and draws water into the UFH circuits.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThermostatic blending valve regulates temperature:\u003c\/strong\u003e A mixture of hot flow water and cooler UFH return water is blended to the correct underfloor temperature (adjustable 30–60°C) before being pumped into the loops.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRoom thermostat satisfied:\u003c\/strong\u003e When the room reaches setpoint, the thermostat breaks the signal to the pump — the UFH pump stops, but the existing heating system continues to run normally.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBoiler shuts down:\u003c\/strong\u003e As the boiler switches off and main flow water cools below 45°C, the pipe thermostat breaks the pump signal and the ZRU goes to standby.\u003c\/li\u003e\n  \u003c\/ol\u003e\n\n  \u003c!-- ── Specifications ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eTechnical Specifications\u003c\/div\u003e\n  \u003ctable class=\"spec-table\"\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMPN \/ Product Code\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"sku\"\u003ePB970028\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003ePolypipe\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eZonal Regulation Unit (ZRU) — 2\/3 Circuit, complete with manifold\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMax Room \/ Extension Area\u003c\/td\u003e\n\u003ctd\u003eUp to 30 m²\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eNumber of UFH Circuits\u003c\/td\u003e\n\u003ctd\u003e2 (built-in manifold); expandable to 3 with standard 15mm fittings\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eFlow Temperature Control\u003c\/td\u003e\n\u003ctd\u003eThermostatic blending valve — adjustable 30°C to 60°C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMinimum Boiler Water Temperature to Activate\u003c\/td\u003e\n\u003ctd\u003e45°C (pipe thermostat make point)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePipe Thermostat: Make \/ Break\u003c\/td\u003e\n\u003ctd\u003eMakes at 40°C \/ Breaks at 32°C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eElectrical Supply\u003c\/td\u003e\n\u003ctd\u003e240V AC, 3A fused spur\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRoom Thermostat Connection\u003c\/td\u003e\n\u003ctd\u003eVolt-free contact (battery-operated or wired thermostat); remove link on wiring block when thermostat fitted\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePipework Connections\u003c\/td\u003e\n\u003ctd\u003e15mm compression — Heating Flow, Heating Return, UFH Flow(s), UFH Return(s)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMinimum Pipe Size to ZRU\u003c\/td\u003e\n\u003ctd\u003e15mm (do not connect from any pipe smaller than 15mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePreferred System Connection\u003c\/td\u003e\n\u003ctd\u003eMain 22mm flow and return distribution pipework of a 2-pipe system\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePressure Rating\u003c\/td\u003e\n\u003ctd\u003ePN6\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMax Ambient Temperature\u003c\/td\u003e\n\u003ctd\u003e60°C (at 95°C fluid temperature)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eWall-mounted — 100mm minimum from finished floor level\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMounting Clearance\u003c\/td\u003e\n\u003ctd\u003e80mm minimum wall clearance for mixing valve adjustment access\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eDomestic and commercial — all Polypipe UFH floor types\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\n  \u003c!-- ── Compatibility ── --\u003e\n  \u003cdiv class=\"compat-strip\"\u003e\n    \u003cstrong\u003eCompatible UFH Systems:\u003c\/strong\u003e Polypipe Overlay™ · Overlay™ Lite · MHP (Minimum Depth) · Solid screeded floor systems · Low surface temperature (LST) radiator applications\n  \u003c\/div\u003e\n\n  \u003c!-- ── Installation Guide ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eInstallation Overview\u003c\/div\u003e\n  \u003cdiv class=\"callout callout-warn\"\u003e\n    ⚠️ \u003cstrong\u003eCompetent person required:\u003c\/strong\u003e All electrical connections must comply with the current edition of BS 7671 (IET Wiring Regulations). Electrical work must be carried out by, or inspected and tested by, a qualified electrician. Plumbing connections must comply with the Water Supply (Water Fittings) Regulations 1999. Always check boiler manufacturer guidance before installing a second pump on the system.\n  \u003c\/div\u003e\n\n  \u003col class=\"steps\"\u003e\n    \u003cli\u003e\n      \u003cstrong\u003ePre-fill UFH pipework:\u003c\/strong\u003e If the ZRU is to be installed after floor screed or coverings are laid, fill and pressure-test the UFH circuit beforehand. Temporarily cap the pipes and keep them full of water (under pressure where possible). Take precautions against freezing in cold conditions.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eSelect mounting position:\u003c\/strong\u003e Ideally mount in the heated room at 100mm above finished floor level to allow pipe connections to exit the floor correctly. The ZRU can alternatively be positioned elsewhere in the property if more convenient. Ensure 80mm minimum clearance to the left of the unit for mixing valve access.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eFix to wall (Step 1):\u003c\/strong\u003e Tape the supplied fixing template to the wall. Mark and drill fixing holes. Insert wall plugs and screw the ZRU body firmly to the wall. Do not over-tighten fixings.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eConnect heating pipework (Step 2):\u003c\/strong\u003e Connect the Heating Flow and Heating Return ports to the existing 2-pipe system via isolation valves. The preferred connection point is the main 22mm distribution pipework. Alternatively connect to the nearest existing radiator. Do not connect from any pipe smaller than 15mm.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eConnect UFH circuits (Step 3):\u003c\/strong\u003e Connect the underfloor heating flow and return loops to the ZRU manifold ports using isolation valves. For 2 circuits, use the built-in manifold ports. To add a 3rd circuit, fit 15mm spigot elbows to the underside exit points and use 15mm tees off the manifold. Blank off any unused ports with spigot blanking plugs. Use PolyPlumb elbow fittings to exit pipes from floor level; cover elbows in polystyrene before screeding to allow future access, or enclose within a PolyPlumb Junction Box.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eWire electrical connections (Step 4):\u003c\/strong\u003e Connect 240V mains supply via a 3A fused spur to the ZRU wiring block as per the wiring diagram in the installation guide. If a room thermostat is being fitted, connect the volt-free contacts to the designated terminals and remove the shorting link from the wiring block. If no thermostat is fitted, leave the link in place — the ZRU will run purely on pipe thermostat control.\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cstrong\u003eFill and commission:\u003c\/strong\u003e Fill the complete system (boiler, radiators, and UFH circuits) and bleed any air. Check all connections for leaks. Set the thermostatic blending valve to the desired UFH flow temperature (typically 35–50°C depending on floor construction). Fire the boiler and confirm the ZRU pump starts when flow temperature exceeds 45°C. Verify correct operation of the room thermostat (if fitted).\n    \u003c\/li\u003e\n  \u003c\/ol\u003e\n\n  \u003cdiv class=\"callout callout-teal\"\u003e\n    ℹ️ \u003cstrong\u003eSolid floor timing note:\u003c\/strong\u003e For solid screeded floor installations, the thermal mass of the floor means slow response times. The timings of the existing central heating may need adjusting so the UFH circuit has sufficient warm-up time before occupancy. Low-mass systems (Overlay™, Overlay™ Lite, MHP) respond much faster and are generally compatible with existing boiler on\/off timing.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"callout callout-amber\"\u003e\n    💡 \u003cstrong\u003eIndependent zone operation:\u003c\/strong\u003e To operate the UFH room completely independently of the existing heating system (e.g. different schedule or setpoint), install a zone valve between the boiler\/distribution pipework and the ZRU Heating Flow connection, controlled by a programmable room thermostat. Without this, the ZRU will only operate when the existing heating system is also running.\n  \u003c\/div\u003e\n\n  \u003c!-- ── FAQ ── --\u003e\n  \u003cdiv class=\"section-label\"\u003eFrequently Asked Questions\u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eCan I add underfloor heating to just one room without changing my existing radiator system?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eYes — that is exactly what the ZRU is designed for. It connects a single room or extension to your existing radiator circuit without any modifications to the boiler, pump, or existing pipework. It has its own pump and mixing valve and manages the temperature conversion internally.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eMy existing system runs at around 75°C. Is that too hot for UFH?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eNot with the ZRU. The built-in thermostatic blending valve reduces the flow temperature to between 30°C and 60°C before it reaches the UFH pipework. You set the blending valve to the appropriate temperature for your floor construction — typically 35–45°C for a screed floor and up to 50°C for a timber floor system.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eDoes the ZRU work if my boiler is a combi?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eYes, the ZRU is compatible with combi boilers. However, note that adding a second pump to the system can affect some boilers hydraulically — always check with the boiler manufacturer that a second pump is compatible before installation.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eWhat happens if my boiler is off? Will the underfloor heating still work?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eNo — the ZRU only operates when the boiler is supplying heat. The pipe thermostat within the unit detects when flow water reaches 45°C and only then starts the UFH pump. If the boiler is off, the ZRU pump will not run. To allow the UFH to run independently on a separate schedule, a zone valve is needed (see installation note above).\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eHow many circuits can the ZRU serve?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eThe PB970028 includes a built-in 2-circuit manifold, so it can serve two UFH loops directly out of the box. A third circuit can be added by fitting two 15mm spigot elbows and two 15mm tees to the manifold — standard PolyPlumb fittings available separately. For rooms over 30 m², Polypipe recommend connecting via a full multi-circuit manifold rather than a ZRU.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eDo I need a room thermostat?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eA room thermostat is optional. Without one, the ZRU operates purely on the pipe thermostat — running whenever the boiler is on and stopping when the boiler shuts down. Adding a volt-free room thermostat (battery-operated or wired) allows the room temperature to be set and maintained precisely, stopping the UFH pump once the room reaches temperature even if the boiler is still running. This is strongly recommended for energy efficiency and comfort.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eWhere should the ZRU be mounted?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eIdeally on the wall of the room being heated, at 100mm above the finished floor level so that the UFH pipe connections exit from the floor cleanly beneath it. If this is not practical, it can be positioned elsewhere in the property — for example in a hallway cupboard — as long as the pipe stat will still accurately detect the system flow temperature.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eWhat pipe size is required to connect the ZRU?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eAll connections to the ZRU are 15mm compression. The ZRU must not be connected to the existing system from a pipe smaller than 15mm. The preferred connection point is the main 22mm flow and return distribution pipework; the system can also be connected from the nearest radiator if more convenient.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eCan the ZRU be used for low surface temperature (LST) radiators instead of UFH?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eYes. Because the ZRU thermostatically controls water temperature, it can also be used to supply low surface temperature radiators where the maximum surface temperature must be limited — for example in schools, care homes, or healthcare settings.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"faq-item\"\u003e\n    \u003cdiv class=\"faq-q\"\u003eWhat floor types is the ZRU compatible with?\u003c\/div\u003e\n    \u003cdiv class=\"faq-a\"\u003eThe ZRU is compatible with all Polypipe wet UFH systems: screeded solid floor systems, Overlay™ low-profile board systems, Overlay™ Lite, and MHP (Minimum Depth Panel) systems. For low-mass systems (Overlay™, Overlay™ Lite, MHP), the fast response means the ZRU works well with the existing boiler's on\/off timer. For solid screeded floors, you may need to advance the existing heating start time to allow the floor mass to warm up in time.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"Polypipe","offers":[{"title":"Default Title","offer_id":63634088657245,"sku":"PB970028","price":670.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/PolypipeZonalRegulationUnit23CircuitZRUCompletewithManifold.jpg?v=1772130862","url":"https:\/\/qualityheating.co.uk\/products\/polypipe-zonal-regulation-unit-2-3-circuit-zru-complete-with-manifold","provider":"AIZO Quality Heating","version":"1.0","type":"link"}