Combination (Combi) boilers are generally considered to be the easiest and most cost-effective way to install a central heating system.
Combination boilers have no tanks or cylinders. Instead, they heat water for central heating and domestic hot water as required (a bit like a pay as you go mobile phone contract, they only start costing you when you make phone calls).
The central heating portion of a combi is on a pressurised closed loop system, heated by the boiler as required. For domestic hot water the mains supply is fed direct to the boiler. This means no hot tank to refill, and a constant supply of hot water at mains pressure.
The issues with this type of system:
- If your incoming cold-water pressure is too low, they will not work correctly.
- If the house has too many bathrooms and a high call or hot water at any one time.
- If they don’t work no back up hot water option.
Although combination boilers are not suitable for all households, they are often the first choice as there is less things to go wrong on central heating system and are cheaper to run.