The new hotun sf range launch

RA Tech UK Ltd, the creator of simple and long-term solutions that solve common heating and plumbing problems, has unveiled the next generation of its best-selling hotun dry trap tundish


The new hotun sf range has been designed to make installation achievable in just a few seconds, with the addition of industry-leading JG Speedfit Technology.

The revolutionary hotun was invented in 2015 by RA Tech Managing Director and experienced plumber, Russell Armstrong, to easily enable installers to discharge unvented water heaters and cylinders Temperature and Pressure Relief Valves, and boiler Pressure Relief Valves, compliantly to a local waste or soil pipe. It also eliminates the risk of odours returning from the foul drain.

Officially accepted for use with boilers and cylinders from the UK’s largest manufacturers, the award-winning hotun dry trap tundish has benefitted from further development. The new range provides a simple solution for boilers, plus small and large unvented cylinders, offering 15mm and 22mm pushfit sizes on the inlet and 22mm compression and 32mm pushfit on the outlet.

All models are WRAS approved and independently tested for flow rate by UKAS test house Kiwa. As well as coping with trickle and low volume flow discharges, the range now boasts flow rates of 16LPM for hotun sf (15/22), 25LPM for the hotun hiflo SF (15/32) and 40LPM on the hotun xlsf 22/32 model, so there will always be a model that will suit a full flow discharge for your application.

Russell Armstrong says: “The hotun is a compact, open-sided tundish that cleverly incorporates a unique and patented in-built non-return valve. It?s an incredibly useful product for any installer to have in their armory, and the development of the new hotun sf range with push-fit fittings now makes it even quicker and easier for installers to use.”

To find the WRAS certificate click this link 

For the UKAS KIWA test results click here

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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