The hotun revolution

This small, simple & affordable product is going to Revolutionise Plumbing and Architecture as we know it, we call it, The hotun revolution


Water is easily seen from above by the installer or homeowner


The Concept

I developed a product that could accept a discharge from an unvented hot water cylinder PRV and connect it to drain compliantly. I had absolutely no idea how well the idea would catch the imagination of the industry.

The initial concept was simple: Providing a compliant connection from the small unvented cylinder to a local drain. However, our horizons were altered irrevocably when we were approached by Worcester Bosch just three weeks after the launch of this little product.

They invited me to come and have a chat. I spoke with some people from their technical team. They liked the concept so much they accepted it for use with their boilers.

Little did I know that the issue of running a landlocked boiler PRV to drain had been causing issues for boiler manufacturers and installers for some time. Amazingly, hotun hiflo has become that solution!

Making Life Easier for Architects and Planners

But the hotun Dry Trap Tundish isn’t just great for boiler manufacturers and installers. The concept of running the PRV to local drain has untold benefits for architects and planners too. On top of this, it provides a cost-benefit out of all proportion to what is essentially a very simple piece of kit.

Traditionally on projects such as flats and spec office developments, all boiler & cylinder PRVs could only be terminated compliantly either externally to the building, or
run down service voids internally to a basement level, where they would each be terminated over an open trapped gulley, they would also have to be individually and carefully labeled to ensure correct identification

This caused no end of hassle for building design engineers and architects. Architects don’t want the external fabric of their buildings unnecessarily festooned with copper pipework. Up till now, his only alternative was to run every individual PRV discharge pipe down the internal of the building. In terms of both labour and material, this process was extremely costly.

How Our Simple Product Fixes an Age-Old Problem

Thanks to the hotun hiflo Dry Trap Tundish, for the very first time, a boiler manufacturer has allowed for this connection to be made internally.

It provides a safe and visible means of discharge within the building envelope. This discharged water can then be run to a local internal drain. The hotun Dry Trap Tundish is a small bit of kit measuring approximately 100 x 60mm. It costs approximately £20 per unit. But despite this, it can save architects and planners thousands of pounds.

Its inbuilt trap provides the ability to pass water through while preventing odours from the drains back into the building. This means that there is no longer any need to run PRVs externally or to take tortuous paths down service voids to the basement. Instead, it is all contained within the confines of the apartment itself.

Safeguards include margins of error in maximum flow rates. Most boilers will discharge between 14 and 18 liters/min if they run open bore, which they normally don’t. The hotun hiflo has a rated capacity of 18 liters/min. Recent UKAS accredited tests prove that hotun hiflo can handle flows of almost 20L/min. What’s more, our new speedfit variants take this capacity up to 25 liters/min. (UKAS Accredited)

We also provide a safety guard for accessible locations (boilers only). It’s a clear plastic shield that clips over the product. This stops curious fingers from exploring potentially scalding hot discharges from the PRV. We call this hotun shield.

The hotun revolution

The hotun range of dry trap tundishes is such a game-changer that some are calling it the next Adey MagnaClean. On top of that, the #hotunRevolution has opened up a whole new world of possibilities for architects and design engineers to explore

Despite being so small, so simple, and so affordable, this disruptive and innovative product is going to make major waves.

For more details please email us at or call us on 01332 702678

Get In Touch

Registered Address

RA Tech UK Ltd
6 Nottingham Road
Long Eaton, Nottingham, UK

T: 01332 702678



In one simple fitting, hotun solves the problem of compliantly running a PRV valve discharge from a pressurised hot water cylinder relief valve or boiler pressure relief valve to a local waste or soil pipe.

hotun combines a tundish and a non-return valve to make a dry trap tundish which acts as a visible early warning device and prevents foul odours from escaping from the waste/soil pipe.


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