Harvey Arc Vs TwinTec S4
Purchasing a water softener online can be confusing - especially when it comes to purchasing the best make and model. f you’ve been researching the Harvey Arc vs TwinTec S4, you’re not alone. Both are compact, non-electric water softeners from trusted UK manufacturers. But which is better for your home – and your wallet?
In this guide, we’ll break it down by performance, efficiency, availability, and value - so you don't pay more than you have to.A Specification Comparison
The TwinTec S4 has the Same Technical Spec as the Harvey Arc
The TwinTec S4 water softener is the best water softener available online and one of the most advanced systems. From automatic regeneration to smart shuttled metering - this system is low maintenance and highly efficient.
Specification
Type of System: Twin Tank
Flow Rate: 56L/min
Efficiency: Non-electric, uses 300g of salt & 17L of water per regenration.
Regeneration Time: 11 minutes.
Size: Height: 49.0 cm, Width: 20.5 cm, Depth: 44.0 cm
Pressure: 1-10 Bar
Salt: Standard Block Salt
Warranty: 10 Years on parts
Price: Only £1149.99 (RRP £1450)
📊 Comparison Table: Harvey Arc vs TwinTec S4
| Feature | Harvey Arc | TwinTec S4 |
|---|---|---|
| Distribution | Retail (direct through Harvey) | Exclusive dealer network |
| Installation | Harvey supplied & installed | DIY, 3rd-party plumber or Dealer-supplied & installed |
| Warranty | 2–5 years (basic cover, 10 years available at extra costs) | 10 years (parts & 2 years labour) |
| Efficiency | Highest salt/water efficiency in class | Highest salt/water efficiency in class |
| Flow Rate | 56L/min (ideal for 3-4 bathroom homes) | 56L/min (ideal for 3-4 bathroom homes) |
| Build Quality | Premium recycled composite casing | Premium recycled composite casing |
| Eco Credentials | Made using recycled materials | Made using recycled materials |
| Service & Support | Via Harvey | Direct from Harvey or local dealers |
| Best For | Homes with high usage or multiple bathrooms | Budget-conscious buyers & homes with high usage or multiple bathrooms |
🧬 Harvey Arc & TwinTec S4 Lineage and Evolution
The TwinTec brand, along with the MiniMax, are manufactured by Harvey, but have been specifically branded differently in order to be sold through different distribution channels. Over the past two decades, Harvey have developed a range of highly regarded water softeners — and whilst the TwinTec brand has the same specification, it is sold through dealer networks. On the other hand, Harvey sells its Arc brand direct from Harvey only.
🏷️ Harvey Water Softeners Timeline
The Harvey HV3
🔹 Released in early 2000s
🔹 Twin-cylinder, block salt
🔹 Non-electric with basic resin efficiency
🔹 Early model
The Harvey HV4
🔹 Successor to the HV3
🔹 Improved water flow and salt usage
🔹 Compact enough for under-sink installation
🔹 Harvey models can last up to 10 years, so the HV4 is still widely seen in UK homes
The Harvey Arc
🔹 Current model.
🔹 Sold via Harvey direct.
🔹 Typically comes with a 2–5year warranty
🔹 Connects to a smart phone app for salt usage alerts.
🛠️ TwinTec Water Softener Range (Dealer-Only)
🛠️ TwinTec Timeline
The TwinTec S3
🔹 Reliable and compact system
🔹 Non-electric with dual-cylinder design
🔹 Very popular for mid-sized UK homes
🔹 Good efficiency but older internal tech
The TwinTec S4
(Current Best Seller - same technical spec as the arc but no smart phone app)
🔹 Fully upgraded for modern plumbing systems
🔹 Best-in-class salt and water efficiency - lowest running costs.
🔹 Flow rate up to 56L/min – ideal for homes with 3+ bathrooms
🔹 Made with recycled plastics
🔹 Full 10-year parts & labour warranty via approved dealers
The Harvey Cobalt
(Newest model, not sold online)
🔹 Same as the Arc but different cabinet
🔹 Enhanced smart features & advanced internal monitoring
🔹 Sleeker casing, slimmer under-sink fit
🔹 Connects to smart phone app
🔹 Currently available through select dealers only
💬 What Homeowners Are Saying About Harvey Arc & TwinTec S4 - Real User Opinions (from forums & Reddit)
These user experiences reflect a common theme: the Harvey Arc and TwinTec S4 deliver comparable performance under the hood—but the Arc often costs more upfront and comes with a shorter warranty. Many buyers prefer the TwinTec S4 for better long-term value and broader availability.
Why People Choose The TwinTec S4
🗣️ “Harvey are definitely worth it but you can get cheaper models like the Harvey TwinTec S4. Basically most of the softeners have the same interior.” — Reddit user on r/DIYUK
🗣️ “Consider buying a Twintec, which is rebranded Harvey but with no frills (who the heck needs WiFi on their softener???) like from here… then get a good plumber to fit it for you.” — Reddit user r/DIYUK, recalling Harvey Arc warranty issue post-3‑year period
🗣️ “Harvey’s Arc Curve salt is only produced by them currently, so you pay a premium... ” — Reddit user, r/WaterSofteners (comparing Arc and TwinTec S4)
🗣️ “We’ve had the TwinTec S4 for a few years now — it’s been flawless. No issues, soft water all the time, and barely uses any salt. It just works. Honestly one of the best home purchases we’ve made.” — Reddit user, r/HomeImprovementUK
🗣️ “Was looking at the Harvey Arc but ended up with the S4 after speaking to installers — they all said it’s better made, easier to service, and runs more efficiently. Zero regrets.” — Homeowner from a UK Plumbing Forum
🗣️ “TwinTec S4 is what most pros install in their own homes. That was enough for me.” — Plumber’s comment quoted on r/AskUK
🗣️ “Everyone seems to push the Arc but it’s mainly because it’s newer marketing. The S4 is still the better system overall — less salt, longer warranty, and it’s been proven for years.” — Customer comment, Trustpilot summary
🤔 Frequently Asked Questions (FAQs)
Q: Is the Harvey Arc superior to the TwinTec S4?
A: No, unless you specifically would like a smart phone app that can alert you on salt. While the Harvey Arc is marketed as a newer model, many professionals and experienced users still recommend the TwinTec S4. The two softeners have the same technical specification and the S4 is known for its long-term reliability, low salt usage, and proven twin-cylinder non-electric performance. In fact, the S4 remains the go-to choice for many UK installers due to its efficiency, warranty, and compatibility with British plumbing systems.
Q: How much does the Harvey Arc cost compared to the TwinTec S4?
A: The Harvey Arc is generally more expensive, but quotations are given through Harvey direct. The TwinTec S4 often offers better value for money at £1149.99 — with the same features — and is more widely available online or through independent installers. This makes it easier to shop around for the best deal.
Q: Is my warranty still valid if a plumber installs my water softener?
A: Yes. With TwinTec, as long as the unit is installed correctly by a qualified person and following the supplied guidelines, the warranty remains valid — even if you don't use a Harvey-approved dealer. But always check the fine print and ask the question to whom you purchase from.
Q: Is there a difference in the warranty between the Arc and the TwinTec S4?
A: Yes. The TwinTec S4 usually comes with a 10-year parts warranty, especially when bought through a recognised supplier. The Harvey Arc comes with a shorter warranty of 5 years. The S4’s longer warranty coverage is one of the reasons it’s so highly rated.
Q: Can I switch from an Arc to an S4 easily?
A: Absolutely. Both systems are similar in size and plumbing requirements, so switching from an Arc to a TwinTec S4 is straightforward — especially if you already have plumbing in place.
Q: Are there any performance differences between the Arc and the S4?
A: They have the same performance on paper.
🧠 Final Thoughts: Harvey Arc or TwinTec S4?
If you’ve been comparing the Harvey Arc water softener with the TwinTec S4, it’s easy to see why both are popular choices in UK homes. The Harvey Arc offers modern touches like smartphone connectivity and sleek branding — but under the hood, it shares the same core technology as the S4. Not only that, but the S4 can b up to £400 cheaper.
For most households, the TwinTec S4 comes out on top. It delivers the same twin-cylinder, non-electric performance, but with added benefits:
- - A longer 10-year warranty
- - Lower price point
- - Broader installer support and online availability
- - Proven reliability with years of real-world performance
Unless app notifications or newer branding are critical to your decision, the TwinTec S4 water softener offers better overall value, long-term savings, and peace of mind — making it the trusted recommendation for installers, engineers, and savvy homeowners alike.
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