PRV discharge pipe routing issues -

PRV discharge pipe routing issues – hotun, the simple solution

PRV discharge process

It is essential that on a sealed heating or hot water system, any PRV discharge can be observed and that passing water is safely directed to a point of discharge. This can be difficult for installers working with a landlocked application or high-rise application where available points of discharge can sometimes be limited to an internal drain. The hotun tundish is fully compliant with building and water regulations and differs from the traditional tundish with its ability to eliminate many of the boiler PRV discharge pipe routing issues installers commonly face.

PRV discharge pipe routing issues -

PRV discharge pipe routing issues

A traditional tundish allows water from a PRV discharge to pass and enables the user to observe this from its open-sided construction, however, complications can occur for installers including limited points of discharge and odours sometimes still travelling back up the boiler?s pressure relief valve discharge pipe if this is connected to drain.

Boiler PRV discharge pipe – how to stop odours with hotun

The hotun dry trap tundish has been purposely designed to help resolve PRV discharge pipe issues by preventing smells from travelling back up the drain connection. The hotun tundish follows the same design of the standard tundish with an open-side to allow the user to witness the passing of PRV discharge but also includes a non-return valve. The non-return valve comprises a one-way sprung valve that closes shut to protect against odours but when water is present and between 5ml and 30ml, the sprung valve is triggered and opens to allow the water to pass through.

Boiler PRV discharge pipe - how to stop odours with hotunPRV discharge pipe issues resolved with hotun

Boiler pressure relief valve discharge pipe – how to combat limited points of discharge with hotun

The hotun hiflo tundish can be used to help combat limited points of discharge for installers working with a landlocked application or high-rise application. It is now possible for the PRV discharge connection to be directly connected to the internal waste and condensate drain pipes with Ideal condensing boilers providing that hotun guidance is adhered to.

Boiler pressure relief valve discharge pipe - how to combat limited points of discharge with hotun

  1. Internal boiler condensate trap
  2. 5mm condensate pipe (must always Tee in below tundish outlet)
  3. 32 – 22mm rubber reducer
  4. Boiler pressure relief valve PRV
  5. 15mm Copper PRV discharge pipe
  6. hotun shield
  7. hotun hiflo (max 600mm from boiler)
  8. 32mm HDPE/PP waste pipe
  9. 32mm universal HDPE/PP waste T fitting (Min 100mm vertical pipe before Tee from Tundish outlet)

Typical compliant installation options for boiler PRV discharge to drain via hotun dry trap tundish

Typical compliant installation options for boiler PRV discharge to drain via hotun dry trap tundish

Typical compliant installation options for unvented hot water cylinders T & P and PRV discharge to drain via hotun dry trap tundish

Typical compliant installation options for unvented hot water cylinders T & P and PRV discharge to drain via hotun dry trap tundish

Benefits of hotun

The hotun dry trap tundish provides installers with a solution to PVR discharge issues that is quicker, easier and cheaper than alternative methods whilst being all under one fully compliant unit. A comparison of the hotun product against other current compliant installation options including average money savings can be found below:

hotun dry trap tundish- solutions to PVR discharge issues

Benefits of the hotun include:

  • Small-sized and ideal for use in small spaces
  • Users are able to visibly see the PVR discharge and can use this as a warning that expert assistance is required
  • Ability to deal with trickle and full flow discharge conditions
  • Flow capacity of 12 litres/minute maximum flow capacity for hotun
  • Flow capacity of 18 litres/minute maximum flow capacity for hotun hiflo
  • Compatible with any unvented hot water heater or sealed system boiler PRV discharge pipe
  • Removes the risk of wholesome water supply contamination (unvented hot water cylinders only)
  • Eliminates the need for any drilling work through external walls
  • Inlet and outlet connections are made with standard plumbing connections

Additional information

The hotun and hotun hiflo PRV discharge products are tested by accredited UKAS bodies and are the only dry trap tundish officially accepted for use by the following:

For further information on boiler applications please click here

For unvented hot water heater applications (under 15 litres capacity) click here

For unvented hot water heater applications (over 15 litres capacity) click here

To buy one of our hotun dry trap tundishes or products please see our trade suppliers list here