No external pump no tanks no external expansion vessel no motorised valves and in many cases item 6 is not needed either.
Combi boiler central heating system diagram.
The central heating portion of a combi is on a pressurised closed loop system heated by the boiler as required.
Instead they heat water for central heating and domestic hot water as required.
They have two heat exchangers inside them.
Combination boilers have no tanks at all.
Central heating wiring diagrams baxi system 818 824 installation and servicing boiler overheating diynot forums doent duo tec combi 24 28 33 40 erp service manual nest thermostat 105e solo pf 2 60 diagram earlier applia help with centre central heating wiring diagrams baxi system 818 824 installation and servicing baxi boiler overheating diynot forums doent baxi duo read more.
A primary heat exchanger.
For central heating 2.
An automatic bypass valve is fitted inside most combi boilers by the manufacturer these days.
This diagram illustrates how simple the heating system connected to a combi boiler is.
Combi boilers heat water directly from the mains when you turn on a tap so you won t need a hot water storage cylinder or a cold water storage tank in the roof space.
In direct contrast open vent also called regular standard or conventional boilers and system boilers heat water that s stored in a tank.
A combination or combi boiler is both a high efficiency water heater and a central heating boiler in a single compact unit.
Central heating system diagram with high pressure boiler this type of system operates at mains water pressure and uses a stored hot water system.
How a combi boiler works at least a modern combi boiler is.