How does a combi boiler circuit work?

[mrmarcus]

Please can somone confirm if I have this right regarding central heating and hot water system using a combi boiler or correct me if I have this wrong;

There will be a Mains water feed pipe to the boiler,
A hot water supply pipe from boiler to go to the hot taps,
A hot water supply pipe from boiler to the radiators,
A returning water pipe from the radiators to the boiler.

Cold water taps would be fed from a branch off the mains supply.

Also is the central heating circuit topped up automatically or manually and is there a pressure release valve in comi boilers or is some kind of expansion vessel required in the circuit somewhere or is it only a pipe to the rads and another back from the rads and the safety stuff is inbuilt into the boiler?

Thanks.

[parapaul]

From what I can see of our Worcest Bosch combi:

mrmarcus said:

Please can somone confirm if I have this right regarding central heating and hot water system using a combi boiler or correct me if I have this wrong;

There will be a Mains water feed pipe to the boiler,
Yes
A hot water supply pipe from boiler to go to the hot taps,
Yes
A hot water supply pipe from boiler to the radiators,
Yes
A returning water pipe from the radiators to the boiler.
Yes

Cold water taps would be fed from a branch off the mains supply.
Yes - although I'd assumed the cold taps were mains fed and the boiler was fed from a branch off.



Also is the central heating circuit topped up automatically or manually
manually
and is there a pressure release valve in comi boilers or is some kind of expansion vessel required in the circuit somewhere or is it only a pipe to the rads and another back from the rads and the safety stuff is inbuilt into the boiler?
just the pipe, any clever stuff is in the boiler

Thanks.