LPG is mainly used where there is no mains natural gas supply to the property and where the customer does not want unsightly oil tanks with the inherent smell of burning oil. These installations can be very discreet and compact.
If room is at a premium as with many homes then perhaps a combination boiler would be best for supplying hot water on demand so there is no need for a large storage vessel for hot water or tanks in the loft. This unit also does the central heating.
If you have a large family and/or house then a sealed central heating system with a cylinder incorporating a solar energy system might be more suitable.
If you have high hot water demands then an unvented hot water system with sealed central heating will supply your hot water demands at mains pressure with the benefits of a sealed central heating system for high efficiency. Alternatively just updating your existing central heating system with TRV’s, a room thermostat and controls via valves to control the temperature of the hot water and central heating will help.
Unvented hot water cylinders give a constant supply of hot water supplied at mains pressure. These installations come into their own when there is a constant high demand; ie a number of en-suites all being run at the same time or when the customer demands good pressure and flow rates