Jargon Buster - E

Confused by DIY terms? We’ve got you covered from A-Z with our Jargon Buster!

Electrolytic Action

Different types of metals used in central heating systems, such as copper and aluminium, can act like a battery in the presence of mildly acidic water, present in some central heating systems, resulting in corrosion.

Electronic Ignition

Most modern boilers have an electronic ignition which has replaced permanent pilot ignition systems (commonly referred to as pilot lights). When the appliance is required to generate heat (either for hot water or for heating the property), a spark is produced at the ignition electrode, supplied from an electronic spark generator, which in turn lights the gas burner of the appliance.

Emergency Control Valve ECV (Sometimes referred to as a gas shut off valve)

This is a device for shutting off the supply of gas in an emergency, which is intended to be used by the consumer of gas, and is installed at the end of a gas service pipe or gas distribution main. In domestic premises, this will be located in close proximity to the gas meter.

English Bond

The English bond consists of alternating rows of stretchers (long faces) and headers (ends), with the alternative headers centred over and under the vertical joints of the stretchers. This is the strongest bonding arrangement possible as there are no continuous vertical joints within the thickness of the brickwork.

Expansion Tank

This is a tank, vessel or housing, designed and built to contain fluids under pressure such as water in a pressurised central heating system. Its purpose is to accommodate the increase in water pressure and volume when water is heated. Inside the vessel, heated water is separated from a volume of air by a rubber diaphragm. When the heated water expands, it exerts a force on this diaphragm, compressing the air on the other side.

Expansion Vessel (see expansion tank)

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