Thetford iNDUS eco, a macerator toilet with a fixed black-water tank, is now standard on Kabe’s top Swedish motorhomes and appears in Hymer’s new 2027 B-Class MasterLine. Neither move has reached UK showrooms yet.

That is the real story behind Thetford’s August press release. Strip out “breakthrough” and “conscious people” and what is left is a supplier pushing liner-class comfort into mainstream motorhomes, with two respected brands as proof.

What Thetford Has Actually Launched

iNDUS eco is a cut-down version of the original iNDUS system Thetford brought out in 2020. Thetford took out grey-water reuse and automatic chemical dosing.

Dirk Valder, Thetford’s Manager of Product Management RV/OEM, called the result “a Tecma-light version”.

The system has five parts:

  • A free-standing toilet with a two-stage macerator (mixing, then pumping). Thetford puts the toilet’s weight at 7.5 kg.
  • A fixed black-water tank, quoted at 50 litres in 2024. Thetford says that equals 2.5 cassettes.
  • A discharge unit with a hose, quoted at 2 m in 2024.
  • An odour filter and waste mixing, which Thetford says make toilet chemicals unnecessary.
  • An app showing tank levels and discharge points. Thetford said in 2024 it draws on Campercontact data covering more than 50,000 locations.

Thetford quotes 200 ml for a small flush and 500 ml for a large one. Its liner-class Tecma Silence 2G weighs 22.5 kg, according to Thetford Marine’s spec page. Thetford’s launch material puts its water use at 2 to 2.5 litres per use, but the same spec page gives a range of 0.5 to 2.7 litres per flush.

That gap is the whole pitch. Home-style flushing without the weight and the water bill.

The “up to seven days off grid” claim is Thetford’s sum, not a test result. Marketing manager Norbert van Noesel set it out in 2024: a 50-litre tank holds 2.5 cassettes, and cassettes are emptied every three days on average.

Real life will vary with tank size, the number of people aboard and how they use it.

Launch timing is also muddier than the release suggests. Thetford first showed iNDUS eco to OEMs at Caravan Salon 2024. First fitments and the full market launch followed in 2025.

What Happened at Caravan Salon 2026

Kabe went further than the release says. Its model year 2027 announcement on 27 August 2026 made iNDUS eco standard in both its fully integrated Crown and Imperial ranges. For model year 2026 it had been an option on those two lines.

Hymer premiered the facelifted B-Class MasterLine at the show, which ran from 28 August to 6 September in Düsseldorf.

German dealer Der Freistaat lists a new Thetford iNDUS system “with macerator and underfloor fixed tank” among the highlights of the 2027 B-ML I 780. Its video of the I 880 refers to a 50-litre waste tank. A Finnish dealer quotes 55 litres.

Hymer’s own launch release does not mention the toilet at all. Thetford calls it an option. We have not yet seen a UK price list that shows it either way.

What This Means for UK Dealers

In the short term, very little changes on the forecourt.

Kabe reaches the UK through Coachman, which Kabe has owned outright since February 2021. Coachman’s UK page for the Travel Master Imperial, the British cousin of the Kabe Imperial, still lists a “Thetford swivel toilet with ceramic bowl, electric flush and wheeled waste container”. That is a cassette.

Hymer is a different case. The B-ML is sold through the Erwin Hymer Group UK network, including Lowdhams, Southdowns, Marquis and Emmbee.

Hymer’s UK site lists the 2027 B-ML I 780 from £150,570 and the I 880 from £161,470. If iNDUS eco reaches the UK order form, these are the buyers who will see it first.

Let’s be fair to Thetford. It is not calling time on the cassette. Its own launch page says research shows cassette toilets “remain the superior choice for the majority of the market”.

Its C220 and C260 cassette toilets have more than 2.5 million installations in Europe, by Thetford’s count. iNDUS eco is aimed at a slice of the market, not all of it.

The UK question is where the waste goes. Thetford says the system will discharge “at any discharge location”, because waste without chemicals can go where treated waste cannot.

That suits the Continent, with its wide network of aires and drive-over service points. England has few standalone motorhome service points. Most emptying happens at campsite chemical disposal points, often raised hoppers built for cassettes.

UK owners on forums report that many drive-over drains on sites are signed for grey water only. A hose-fed black tank needs a ground-level drain, a manhole, or the site’s say-so.

Until Thetford shows how the discharge unit copes with a raised Elsan point, treat “any discharge location” as a Continental promise, not a UK one.

What UK Dealers Should Do Now

  • Ask your Hymer area manager whether iNDUS eco will be on the UK B-ML order form for 2027, at what price, and whether it is standard or optional.
  • Get the discharge detail from Thetford UK in writing. Is draining by gravity or by pump, how long is the hose, and can it reach a raised chemical disposal point?
  • Prepare a straight answer for the buyer who asks: “Can I empty it on a UK site?” Know which sites near you have ground-level drains.
  • On your website and spec sheets, say “macerator toilet with fixed black-water tank” in plain words. Do not lift “liner-class” or “seven days” without the conditions attached.
  • At handover, walk the owner through emptying, flushing the tank through and winter care. A fixed tank cannot be carried to a sluice like a cassette.
  • Brief your workshop. A macerator pump, tank sensors and an app add parts that can fail. Ask Thetford about UK parts stock and training before the first unit lands.

The Bigger Picture

Toilets have become a selling point, not an afterthought. In two years Thetford has added separation toilets, separation kits and iNDUS eco alongside the cassette.

Rivals are pushing bag-welding systems. Dethleffs, Hymer’s sister brand in Erwin Hymer Group, now fits Clesana’s waterless C1 bag-welding toilet ex works, according to Clesana. Dethleffs UK lists it as a factory option.

Valder says Thetford sees “high interest” among OEMs in both southern and northern Europe for “season 2028-2029”. He named no brands and gave no volumes. Read it as a sales goal, not an order book.

The likely outcome is a split market. Cassettes stay the default for most UK motorhomes, where cost, weight and site layout favour them. Fixed black tanks creep down from the liners into upper-premium A-class models first, led by brands such as Kabe and Hymer.

For dealers, the next step is simple. Find out before your customers do whether the UK-bound 2027 B-ML carries iNDUS eco, and how a UK owner is meant to empty it.