22mm Compression
23–45 L/min Optimum Flow
Catalytic — No Chemicals · No Power
WRAS Approved
10-Year Warranty
Made in Britain
The Stuart Turner C23-45 is a catalytic water conditioner for 22mm pipework, designed for whole-house limescale prevention in domestic properties with a mains flow rate of 23–45 litres per minute. Its unique catalytic alloy core converts calcium carbonate in the water into microscopic suspended crystals that cannot adhere to any surface — keeping boilers, cylinders, taps, showers, and kitchen appliances free from hard limescale build-up without salt, chemicals, or any external power supply. WRAS approved and backed by a 10-year manufacturer's warranty, it is one of the most trusted and established water conditioning solutions available in the UK.
Stuart Turner has been manufacturing water management products in Britain since 1874 — and the Stuart Water Conditioner range reflects the same engineering standards that have made the brand the UK's leading shower pump and booster pump manufacturer. The C23-45 is the mid-range model in the three-strong domestic conditioner line-up, covering the flow rates typical of larger homes, properties with 22mm mains supplies, and higher-demand water systems. Correct sizing to the actual flow rate of your incoming supply is the key to effective catalytic conditioning — and the Stuart range provides three precisely calibrated options to cover all domestic scenarios.
Why Choose the Stuart Turner C23-45?
⚗️ Catalytic Alloy Core TechnologyThe catalytic alloy core — not salt, not magnets, not electricity — triggers a physical change in calcium carbonate as water flows through the unit. Calcium precipitates as microscopic non-adhering crystals that stay in suspension and flush harmlessly away.
🏠 Whole-House ProtectionInstalled once on the incoming mains supply after the stopcock, the C23-45 conditions all water entering the property — protecting every boiler, hot water cylinder, radiator, tap, shower, kettle, dishwasher, and washing machine simultaneously.
🔧 Zero Maintenance — EverNo salt to add, no cartridges to replace, no electrical components, no servicing. Install it once and it works continuously with no user input for its entire 15-year average active lifespan.
✅ WRAS ApprovedWRAS (Water Regulations Advisory Scheme) approved — product approval reference 1606370 — confirming it is suitable for use on drinking water systems in accordance with UK Water Regulations.
🍼 Safe for Drinking & Baby FormulaUnlike salt-based softeners, no sodium is added to the water. Treated water is safe to drink directly from the tap and is confirmed safe for preparing baby formula.
💧 Treated Water Stores for 3 MonthsThe catalytic treatment is stable — treated water stored in a cylinder, tank, or vessel remains conditioned for up to three months, making it suitable for systems with cold water storage tanks.
📐 Any Orientation — Any PositionThe compact 290 × 34mm cylindrical body installs in any orientation — horizontal, vertical, or diagonal — making it adaptable to almost any pipework arrangement, including installations with limited space around the stopcock.
🌱 Environmentally FriendlyNo salt brine discharge into drainage systems. No chemical waste. No electricity consumption. The catalytic alloy core works passively using only the kinetic energy of the water flow itself.
📋 Supports Part L ComplianceInstallation of a Stuart Water Conditioner can play an effective role in demonstrating compliance with Part L of the Building Regulations (Conservation of Fuel and Power), which requires optimisation of fuel and power use — relevant in both new-build and renovation projects.
⚡ Quieter, More Efficient AppliancesLimescale insulates heat exchangers, forcing boilers and water heaters to work harder — increasing energy consumption and noise. By preventing limescale build-up from the outset, the C23-45 helps appliances run at their designed efficiency throughout their working lives.
🏭 British Engineering Since 1874Stuart Turner is one of Britain's oldest and most respected fluid management manufacturers. The Water Conditioner range is designed, tested, and manufactured in the UK to the same exacting standards as their renowned pump range.
🛡️ 10-Year Manufacturer's WarrantyBacked by Stuart Turner's full 10-year warranty — exceptional coverage that reflects both the product's build quality and the manufacturer's confidence in its long-term performance.
How It Works — Catalytic Conditioning Explained
The Stuart Turner C23-45 uses a fundamentally different approach to limescale prevention compared to either salt-based softeners or the galvanic/zinc anode technology used by some competing products. Its core is a precision-engineered catalytic alloy — a proprietary metallic formulation that acts as a catalyst when water flows across its surface.
As mains water passes through the conditioner, the catalytic alloy surface triggers nucleation — the process by which dissolved calcium carbonate (CaCO₃) begins to crystallise. Crucially, the catalyst controls how and where this crystallisation happens: rather than forming at pipe walls, heat exchanger surfaces, or appliance elements (which is what produces traditional hard limescale), the calcium crystallises in the bulk of the water flow itself, forming vast numbers of microscopic aragonite crystals that remain in suspension.
💡 Why the crystals don't stick
These microscopically small crystals have a very high surface-area-to-volume ratio and a slightly negative surface charge. Both properties make them energetically unfavourable to bond to pipe and appliance surfaces — they prefer to remain in suspension and are simply carried along with the water flow, eventually draining away through normal use. This is a permanent physical change to the calcium, not a temporary field effect — the crystals remain non-adhering whether the water is stored, heated, or used immediately.
Unlike magnetic or electronic conditioners, whose claimed effects depend on externally applied fields that dissipate quickly as water moves away from the treatment zone, the catalytic conversion in the C23-45 produces a permanent crystalline change that persists through the entire plumbing system. Treated water stored for up to three months retains its conditioned state — beneficial for properties with cold water storage tanks where the treated water may sit before use.
The catalytic alloy is not consumed by the process — it acts purely as a catalyst, meaning its ability to trigger nucleation does not deplete over time. Stuart Turner quotes an average active lifespan of 15 years, with a 10-year manufacturer's warranty giving confident long-term coverage.
Choosing the Right Model — C23-45 vs. C3-22 vs. C46-75
Stuart Turner sizes their water conditioners by the optimum flow rate range of your incoming cold water mains, not by pipe diameter alone. The C23-45's 22mm compression connections fit the 22mm mains pipework typical of larger homes, but sizing by flow rate is what determines effectiveness — a 22mm supply at low flow rates may still be better served by the C3-22, while a particularly high-demand property may require the C46-75.
| Model |
Part No. |
Optimum Flow Rate |
Connection |
Length |
Best For |
| C3-22 |
44617 |
3–22 l/min |
15/22mm compression (with 15mm reducers) |
265mm |
Smaller homes, 15mm mains, lower-flow supplies |
| C23-45 ★ This product |
44618 |
23–45 l/min |
22mm compression |
290mm |
Larger homes, 22mm mains, medium-to-high flow |
| C46-75 |
44619 |
46–75 l/min |
22mm compression |
— |
High-flow or large domestic properties |
📏 How to measure your mains flow rate: Use a bucket (measured in litres) and a stopwatch. Turn on a cold tap fully, time how long it takes to fill the bucket, and calculate litres per minute. Do this at a tap that is direct-fed from the mains (not via a tank). Match the result to the table above. If your flow rate falls between models or you are unsure, contact your plumber or Stuart Turner's TechAssist team for advice.
Installation
The C23-45 is installed inline on the incoming cold water mains, immediately after the main stopcock — before the supply reaches any branch point, appliance, or tank. This ensures the entire household water supply is treated. It connects using the supplied 22mm compression fittings, making it compatible with standard 22mm copper or plastic mains pipework. No specialist tools are required; a competent plumber can typically complete the installation in under an hour.
The unit can be installed in any orientation — horizontal, vertical, or at any angle — which is a significant practical advantage in tight, congested under-sink or utility room installations where many competing products require a specific orientation for correct operation. Flow direction should follow the arrow marked on the body.
✅ Installation Checklist
Install after the main stopcock, before any branches · 22mm compression fittings supplied in the box · Any pipe orientation is acceptable · No electrical connection required · No bypass required but recommended for servicing access · Install an isolating valve each side for future maintenance. Full installation guide available to download from Stuart Turner's website.
The Stuart Turner Advantage — British Engineering, Exceptional Longevity
Stuart Turner's water conditioners are notable for their average 15-year active lifespan — significantly longer than many competing salt-free conditioning products, whose zinc anodes or other consumable elements deplete over 7–10 years and require unit replacement. Because the catalytic alloy in the C23-45 is not consumed by the conditioning process, the unit's effectiveness does not gradually decline in the same way. Stuart Turner's TechAssist team and national network of service engineers also provide a level of manufacturer support rarely available from smaller conditioner brands.
The C23-45 holds WRAS approval (1606370) — a rigorous UK certification process that confirms a product does not adversely affect the quality of drinking water. It is also UKCA and CE marked, confirming compliance with applicable UK and European product safety regulations.
Key Features
-
Catalytic alloy core — converts calcium carbonate into non-adhering suspended microscopic crystals
-
Optimum flow rate: 23–45 l/min — calibrated for medium-to-high mains flow rates
-
22mm compression connections — fits standard 22mm copper and plastic mains pipework
-
Stainless steel housing — durable, corrosion-resistant construction
-
Install in any orientation — maximum installation flexibility
- Maximum operating pressure: 10 bar
-
Whole-house treatment — installed once at the mains entry point
-
Treated water stores for up to 3 months — suitable for cold water storage systems
-
Zero maintenance — no salt, chemicals, electricity, or periodic servicing
- Average 15-year active lifespan
-
WRAS approved — approval reference 1606370 — safe for drinking water systems
- UKCA / CE marked
- Supports Building Regulations Part L compliance
-
Drinking water safe — no sodium added; safe for babies and low-sodium diets
-
Environmentally friendly — no salt discharge, no chemical waste, no electricity
-
Made in Britain by Stuart Turner — established 1874
- 10-year manufacturer's warranty
- MPN: 44618 | EAN / GTIN: 5050400446187
Technical Specifications
| Specification |
Detail |
| Model / Product Name |
Stuart Turner C23-45 Water Conditioner |
| Part Number (MPN) |
44618 |
| EAN / GTIN |
5050400446187 |
| Conditioning Technology |
Catalytic alloy core |
| Optimum Flow Rate Range |
23–45 l/min |
| Maximum Operating Pressure |
10 bar |
| Connection Size |
22mm |
| Connection Type |
Compression (brass) |
| Housing Material |
Stainless steel |
| Length |
290 mm |
| Diameter |
34 mm |
| Weight |
0.95 kg |
| Installation Orientation |
Any — horizontal, vertical, or angled |
| Power Required |
None |
| Chemicals / Salt Required |
None |
| Maintenance Required |
None |
| Treated Water Storage |
Up to 3 months |
| Average Active Lifespan |
15 years |
| WRAS Approval |
Yes — approval reference 1606370 |
| Conformity |
UKCA / CE |
| Country of Manufacture |
Great Britain |
| Manufacturer's Warranty |
10 years |
Frequently Asked Questions
How is catalytic conditioning different from galvanic (zinc anode) conditioning?
Both approaches convert calcium carbonate into non-adhering aragonite crystals, but the mechanism differs. Galvanic conditioners (such as Aquabion) use a sacrificial zinc anode that releases zinc ions into the water — the zinc ions react with calcium to trigger the phase change, but the zinc anode is gradually consumed and the unit must be replaced after 7 years. The Stuart Turner catalytic alloy acts as a true catalyst: it triggers the calcium crystallisation without itself being consumed, resulting in a longer average active lifespan (15 years) and no periodic replacement of internal components. Neither system adds sodium or removes minerals from the water.
Will I still see limescale deposits?
You may see some deposits — but they will be soft, powdery aragonite rather than hard, adhering calcite. Soft deposits on shower screens, kettles, and tap fittings wipe away easily without chemical descalers or scrubbing. You will not see the rock-hard, surface-bonded scale that damages boiler elements and blocks pipes.
How do I know if the C23-45 is the right size for my home?
Measure your mains flow rate: fill a bucket of known volume (e.g. 10 litres) from a direct mains-fed cold tap fully open, and time how long it takes. Calculate litres per minute. If the result is between 23 and 45 l/min, the C23-45 is the correct model. Below 22 l/min, choose the C3-22. Above 45 l/min, choose the C46-75. Do not exceed the upper limit of the optimum range — oversizing reduces conditioning effectiveness.
Is it safe to drink the treated water?
Yes — the C23-45 is WRAS approved for use on drinking water systems (approval reference 1606370). It adds no chemicals, salt, or other substances to the water. The catalytic alloy is inert in contact with drinking water. Treated water is safe for all domestic uses including baby formula preparation.
Does it work on a cold water storage system (indirect system)?
Yes — install the conditioner on the incoming cold water mains supply before it reaches the cold water storage tank. The treated water fills the tank and retains its conditioning for up to three months of storage, which covers the vast majority of domestic usage patterns.
Can it be installed on plastic (MDPE or plastic mains) pipe?
Yes — the 22mm compression fittings are suitable for copper or plastic mains pipework. Ensure the correct olive and compression fitting type are used for the pipe material (a plumber will know which). The conditioner body is stainless steel and compatible with all standard UK mains pipe materials.
Does it protect against existing limescale?
The C23-45 prevents new hard limescale from forming. Some softening of existing deposits may occur over time as conditioned water flows past them, but it is primarily a preventative product. If substantial existing limescale is present in a boiler or cylinder, a professional descaling service or power flush may be advisable at the time of installation.
How long does it last and when should I replace it?
Stuart Turner quote an average active lifespan of 15 years for the catalytic alloy core — significantly longer than zinc anode-based conditioners. The 10-year manufacturer's warranty provides comprehensive coverage over a major portion of this lifespan. Unlike consumable-based systems, there is no gradual depletion indicator — the unit either works or it does not. If you have had the unit for over 15 years, it is advisable to replace it as a precaution.
Does it need a bypass valve?
A bypass is not required for operation, but it is good plumbing practice to install isolating valves (service valves) on either side of the conditioner when fitting it. This allows the unit to be isolated and removed for inspection or replacement without shutting off the entire mains supply, which is particularly useful in properties where the main stopcock is inconvenient to access.
What's in the Box
- 1× Stuart Turner C23-45 catalytic water conditioner
- 22mm compression fittings (both ends)
- Installation guide
⚠️ Important Notes: Installation should be carried out by a competent plumber in accordance with the Water Supply (Water Fittings) Regulations 1999 and the installation guide. Install after the main stopcock, before any branch points or storage tanks. Ensure the flow direction arrow on the body is aligned with the direction of water flow. Do not use if the incoming mains flow rate consistently exceeds 45 l/min — use the C46-75 (44619) instead. For flow rates below 23 l/min, use the C3-22 (44617). Not suitable for treating water above 10 bar. For commercial-scale flow rates, see Stuart Turner's CM (commercial/magnetic) range.
