Hot & Cold Water Tanks

For those properties with an older water system there may be a hot and/or cold water tank located in the loft or another high point in the building, but it’s important not to ignore them.

These tanks may supply a hot water cylinder, but also supply water directly to toilets, urinals and cold water taps.  The problem with these tanks is that they can have a build up of sludge, develop scum, sometimes corrode, leak and also attract bird and insects.

When a tank is in poor condition it can cause serious health issues.  One of the most dangerous is legionella bacteria, which colonises stagnant warm water where there are nutrients from scale.  The bacteria can cause Legionnaires’ disease when tiny droplets are inhaled, for example when water splashes in a sink.

There are requirements for water installations, however; older tanks may not meet today’s expectations.

Rules are described in the Water Supply (Water Fittings) Regulations 1999, which plumbers must follow.

Tips for checking and maintaining your tanks:

• Safe access to the tank in order to inspect, clean and maintain is needed
• Check for a tight fitting lid – often the lid may be missing or has been replaced by a piece of timber. Such lids can often sag, break up and sometimes end up in the water
• The lid is there to stop vermin, birds and insects from getting into the tank (needs to be tight fitting, not necessarily air tight)
• Take a look inside at the bottom of the tank – silt occurring over time should be cleaned, which can be completed by a plumber
• Assess the surface of the water, if there’s scum on the top then it is stagnating – again this can be dealt with by a plumber
• There should be insect screens on the air inlet (poking out of the lid) and on the overflow – a plumber can check this
• Check that the tank is insulated on the sides and top ideally with plastic-encased rockwool.