On Thu, 07 Jul 2005 12:48:20 +0100, F wrote:

On 07/07/2005 12:23 Tony Bryer wrote:

You're confusing a system boiler and a combi. A system boiler includes a
pump and will have flow and return connections like any other boiler. A
combi adds main cold water in and DHW out to serve the hot water taps,
the hot water being heated when required.

I understand combis (I think!): they heat cold water straight from the
mains and send it straight to a hot tap. The heated water isn't stored.

The better models have a store to assist with short term flow rate.


Are you saying that the only difference between 'system' and 'heating'
is the presence of a pump within the casing?

In many cases: yes. However it is common to also find that a system
boiler will also include the components for a Sealed system. See FAQ.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html