Ballon D’Eau

What this refers to is the installing of Unvented Hot Water Storage Systems.

The law, which is explained in Building Regulations Approved Document G3, states that an UHWSS must be installed by a 'competent' person. By 'competent', the Building Regulations Approved Document G3 says:

Installation
3.8 The unit or package should be installed by a competent person, i.e., one holding a current Registered Operative Identity card for the installation of unvented domestic hot water storage systems.

Dave Green Plumbing holds a Registered Operative Identity card - Reg No: 04162038/1

The main reason why it's so important to make sure anyone installing, servicing or repairing your UHWSS is 'competent' under the government's legal definition is because unvented hot water cylinders have the potential, when they go wrong, of exploding with incredible, destructive force.

Because of this, UHWSS come with numerous safety features designed into them, all of which should mean it's impossible for the cylinder to fail. But, rather obviously, these safety features must be in working order if they're to operate correctly.

While it is incredibly rare for an UHWSS to fail, if your UHWSS has been 'repaired' or 'installed' by someone not legally competent, or a problem has been ignored by the home owner, then the potential for your UHWSS to malfunction or even explode is obviously increased.

Those of you who live in Ware may remember the explosion at Mill Acres, on Station Road, in 2002, which was caused by an UHWSS. If you saw the aftermath then you will also have seen that the large hole in the building's exterior was nothing compared to the internal damage. Ware Online has a small article on the explosion.

The reason why an UHWSS can be so destructive is because one litre of boiling water, when held under pressure in a cylinder, is suddenly exposed to air, that one litre of water expands to up to sixteen thousands litres of steam.

Unvented Hot Water Storage Systems are incredibly safe and efficient, but they require installing, servicing and repairing by people who are legally competent. No matter which plumber you choose, make sure they have a current Registered Operative Identity card.