It depends on heat loss, number of bathrooms, hot-water demand, available fuel and existing pipework. A heating professional should survey the property and calculate the load.
Central Heating Appliances for Different Fuels and Systems
Choosing a boiler starts with the property, not the appliance badge. Heat loss, hot-water demand, fuel availability and the existing system all affect the specification. MacBlair stocks combination boilers, system models and off-grid heating options for replacement and new installations.
A combi heats mains water as it is needed and does not use a separate hot-water cylinder. A system boiler works with stored hot water, which may be a better fit where several outlets can be used together. The installer should calculate output rather than simply matching the old boiler’s rating.
Properties without mains gas can compare LPG heating appliances with oil-fired boilers. Fuel storage, delivery access, flue position and maintenance requirements belong in that decision.
Installation and combustion work are not DIY tasks. Use a Gas Safe registered engineer with the correct appliance and fuel qualifications for gas or LPG, and an OFTEC registered technician for oil work. The boiler, controls, flue, condensate route and heating-water treatment must be commissioned as one system.
Boilers FAQ's
A combi produces hot water directly without a separate cylinder. A system boiler heats stored water in a cylinder and can better support several outlets used together.
An installer assesses room dimensions, insulation, windows, emitters, design temperatures and hot-water demand. Replacing like for like by kW alone can lead to oversizing.
No. Gas boiler installation, commissioning and gas work must be completed by a Gas Safe registered engineer qualified for that appliance and fuel.
Check system condition, controls, flue route, condensate drainage, gas or oil supply, water pressure and radiator sizing. Cleaning and protection may also be required.