According to Heat and Plumb, Conventional Central Heating ... needed for this are stored in the boiler itself, making it more compact than the previous system. The unvented system is enclosed ...

If you're hearing a clicking or tapping sound and your boiler is struggling to fire up, it is most probably ignition failure.

It can be a self-contained electrical-powered unit that heats an internal reservoir of liquid (electric hydronic baseboard heater), or one integrated into a home’s central heating system boiler ...

They perform the same role as a gas, oil or LPG boiler in a central heating system, but use ambient heat from the ground instead of burning fossil fuels. Heat pumps are more environmentally friendly ...