Condensing boilers are water heaters fuelled by gas or oil. They achieve high efficiency (typically greater than 90% on the higher heating value) by condensing water vapour in the exhaust gases and so recovering its latent heat of vaporisation, which would otherwise have been wasted.
Combi boilers are the most common boiler type in the UK with over 70% of UK homes choosing them. Combination Boilers work by instantly heating water from the mains as soon as a shower or hot water tap is turned on making them efficient and also there is no need for a separate water cylinder or tank.
In 1996 the government passed a law that requires all landlords, who rent either part or all of a property, to have all household gas appliances and pipes checked every 12 months. They are also expected to hold a Landlord certificate for Gas Safety (CP12) that attests to this effect.
If you are planning on having your home renovated then perhaps it is worth considering having a water underfloor heating system installed. Underfloor heating installation (also known as underground heating or water underfloor heating installation) and free up wall space (no need for radiators) and give a clean interior design.
Unvented water cylinders store water at high pressures and are therefore able to supply water at similar pressures to the cold water supply. The increased pressure also ensures better showers without the need for pumps. With both hot and cold water services fed from the mains, there is no more need for a cold water tank, keeping loft spaces clear, and pipe work to a minimum.