Harvey TwinTec S4 Review

Looking to purchase a water softener? We’re here to help. This post is a Harvey TwinTec S4 review. It includes a full breakdown of the pros and cons when purchasing this machine.

What Is The Harvey TwinTec S4 Water Softener?

The Harvey TwinTec Series 4 is a twin tank and non-electric water softener which has been designed in the UK by Harvey Water Softeners. If you have been googling water softeners in the UK, you may have already come across Harvey and their range of different models.

The Series 4 model is one of the most up to date, which offers a great cost-effective water softening solution with an almost identical specification as newer models.

Formerly Known as …

The previous model of the TwinTec S4 was the Harvey TwinTec S3.

Harvey TwinTec S4 Review
Image Credit: TwinTec

Is It the Best Choice for My Home?

This softener is designed for family homes with up to 3 bathrooms. 

The Harvey TwinTec S4 Review Score & Rating


Rating: 5 out of 5.

Summary: What’s Great About This Softener 

Great Capacity, Small in Size, the Most Efficient and Great Value For Money. 

We found this product to have a great technical spec – and  appears to be one of the most efficient on the market. It is suitable for areas with very hard water, has a great flow rate of 56L/Min, a high soft water capacity and is also small in size.

When compared to other softeners online, the salt and water usage was lower per regeneration – meaning you’ll have the cheapest running costs. Not only that, but in comparison to other Harvey model specifications (The Arc, MiniMax and HV4) we found the technical specification to be the same.

At £1249.99 the TwinTec is the best water softener on the market in terms of specification, combined with price and value for money. You’ll get a softener that is designed to last at the least 10 years – with a 10 year warranty.

Summary: What’s Not So Great About This Softener 

Not The Newest Model & No Advanced Technology.

We live in the age of the digital era. With everything we could possibly need at the touch of a button. This softener was released in 2019/2020 – and therefore lacks current digital smart phone technology. Unlike the newer Harvey Arc, which comes with a downloadable app that can tell you when your water usage and exactly when salt is running low. It is worth noting however, that despite the absence of smart phone technology, the technical specification of the Series 4 is exactly the same as the Arc.

The actual softener design and appearance seems irrelevant – given it fits underneath your kitchen sink. But if you are a tech wizz and need the latest up to date of everything – it might be your decision to pay £400-£500 more for the Arc. 

However, the drawback of a newer model like the Harvey Arc, is that you will likely be paying a lot more for essentially the same product. So, the decision really depends on if you want the best value for money and cheaper option or a digital focus with a mobile app preference.

The Technical Specifics:

  • Design & Type 

Non-electric, Twin Tank, requires block salt. 

  • Size

Hxwxd: 490 x 205 x 440mm.

  • Performance & Efficiency 

Salt: 300g per regeneration.

Water usage per regeneration: 17L.

Regeneration time: 11minutes.

  • Flow Rate & Soft Water Capacity 

Max Flow Rate: 56L/min.

Soft Water Capacity: 500L

Max Hardness Level: 635ppm

Min/Max Pressure: 1-10Bar.

  • Durability & Certification

WRAS certified.

  • Warranty 

10 Year Warranty for parts.

The Pros 

  • Its size. In general, you should always check to see if your home has enough space under the kitchen sink for a softener. The Harvey S4 is one of the smallest we have seen in terms of dimensions and so is ideal for fitting. 
  • No need to worry about regeneration and programming. This unit is non–electric and works using a smart metering system. It is automatic and you don’t have to add in times or worry about setting regeneration times.
  • It has a twin tank. Two tanks allow for constant soft water. It also means the softener has a capacity big enough family homes with up to 3 bathrooms.
  • High flow rate and can soften very hard water. Harvey claims up to 635ppm.
  • It is designed for high flow systems and combi boilers. Which means less worry about pressure drops.
  • Low running costs and high efficiency. It has some of the lowest salt and water usages we have seen.
  • 10-year warranty on parts and 2 years labour. The warranty stands regardless of your installer. Meaning you can have a plumber do the job. A 10 year warranty offers a great value on money in terms of product lifespan.

The Cons 

  • No mobile technology. It is by no means dated – but the S4 is also not the latest Harvey release. Newer models have increased technology and a mobile app which can tell you when your salt is running low (although they are around £400-£500 more expensive).
  • May struggle in larger homes with more than 4 bathrooms. For large families this softener may struggle and may not be big enough to supply soft water to the whole home.
  • Hard to find. Harvey softeners and products are mainly sold through Harvey direct and resellers offline and so are hard to find online. Prices can vary offline depending on where you buy it.

Harvey TwinTec S4 Price, Value & Where to Buy

£1199.99 – £1599.99

The S4 is advertised online across several different websites. For online purchasing and the best price, we found North East & Yorkshire Water Softeners to be the cheapest. NE Water softeners are currently advertising £100 off all systems with the discount code HARVEY – meaning you can buy this system for £1149.99 without an installation kit and £1249.99 with an installation kit.

This softener seems to be a great choice and you can find more info at Twintec.

We hope this Harvey TwinTec S4 review has been helpful, if you want to keep researching, checkout our other reviews below.

Before you buy check out these other Reviews…

The Harvey Arc Water Softener Review

The Kinetico Premier Compact Review

The Harvey Crown Water Softener Review