Severn Trent Water and Yorkshire Water estimate that at least 50% of under-counter unvented water heaters are installed non-compliantly.

What is non-compliant?

Is your unvented hot water heater installation compliant?

Did you realise that hard piping the pressure relief valve to the waste pipe (like the one in the picture below) is non-compliant with, and does not conform to, the water or building regulations?

Non-compliant install

Fitting a non compliant installation is illegal and if a building owner/user is issued with a non compliance notification and fail to rectify the notice they would be served with an enforcement order/notice, if they then fail to comply they could be criminally prosecuted and if found guilty, receive a fine.

We see many, many water heater pressure relief valve discharges installed like this one, in fact anecdotal evidence suggests that well over 50% of installations are non-compliant.

Why is this installation non-compliant?

Because the regulations state that…

• If the PRV discharge is connected to a foul waste or soil pipe there must be an ‘air break to drain’ This is a requirement to prevent ANY potential fluid coming back up from the foul (category 5 fluid hazard) drain and contaminating the “wholesome” hot water. A non-return style valve simply does not give enough protection against this potential hazardous contamination.

• Equally important is that if it is hard piped there is no visible signs of water discharge (leading to undue consumption) and…

• There will be no visible warning to indicate something is wrong with the water heater itself or the expansion vessel!

But if so many are fitted this way non compliantly…

Why are they fitted this way?

Is it because the installer…

• Had no knowledge of the requirements?

• Had a lack of cost effective credible alternatives?

• Was unaware of the current water and building regulations?

• Had simply ‘always done it that way’ and no one had said anything was wrong?

Now there is no excuse, because hotun has been invented so that installations can be done compliantly – quickly and easily.

So, what is compliant then?

Using hotun makes the installation compliant

Compliant install

hotun allows the installer to pipe the discharge from the PRV, locally to a foul waste or soil pipe.

But what about foul odours?

Just fitting a standard tundish won’t prevent foul odours. Fitting a non-return enclosed type valve won’t act as an “air break to drain” and maybe you can’t a discharge pipe to the outside wall to a safe point of discharge or it’s not cost-effective. The answer to your problem is to….

Fit a hotun dry trap tundish – Be fully compliant. Easier, and quicker, less costly hotun provides…

A tundish – to provide visual evidence of a fault

An airbrake to drain – to prevent foul backflow from the drain contaminating the wholesome water

A visible means of discharge – to drain over pressure discharge

A non-return valve – to prevent foul odours