A motorhome toilet system that uses grey water to flush, lets you know when it is full and automatically empties through a hose has been launched by Thetford.

The company says its Indus system has been designed to “jump the curve” in the development of motorhome toilets, offering freedom and convenience and the ability to go “off-grid” without having to empty the system for up to seven days.

It works by using grey water from the grey water tank to flush the toilet, and using three different additives which are added automatically to break down the macerated waste product.

Grey and black water can then be disposed of at the touch of a button via a 2m hose connected to a dosing module shaped a bit like a plunger.

This can be positioned over any conventional grey water disposal point, provided it is connected to a main sewer, which Thetford says most are.

A specially created app lets you know when the toilet needs emptying or additives need replacing. It can also direct you to the nearest of over 25,0000 disposal points it has listed across Europe, using a system designed by CamperConnect.

A replacement pack of additives costs €29.95 – prices in sterling are yet to be fixed.

The Indus system has been five years in the making, and is initially going to be fitted in all new Bürstner models for the 2021 season. The company says it is in discussions with other manufacturers about fitting the system in their models, but so far can only say publicly that Adria has also expressed an interest in fitting the system to some of its models this season. The toilet itself, which comes with a soft close lid, has also been designed to stand free of any wall to make it easier to clean.

Because of the complexity of the system, it cannot currently be retrofitted, although Thetford says it is possible that in the future parts of the system might be available for retrofitting.

It is also making a version of the system designed for people who may want to stay on one site longer than a week. This will include a 20-litre tank that can be removed.

Thetford says it has designed the system after conducting research that found that motorcaravanners were emptying their toilet and grey waste water tanks much more frequently than they needed to, because they were relying on guesswork to determine when they are full.

Thetford marketing manager Norbert van Noesel said that although the new system is focused mainly on freedom and convenience, it has strong environmental credentials too, over and above all the additives being biodegradable. “By re-using grey water for toilet flushing, people save on average 112 liters of fresh water per four weeks and therefore also the same amount of waste water,” he said.