Could someone please explain what a fully modulating combination
boiler is, or point me to a source online where I could read up about
this myself

Also does anyone know were I could find documentation such as
installation,
maintenance and specification for the Vaillant boiler VCW GB 242 EH, I
have tried the Vaillant litereture line several times, but they seem
incapable of sending anything out.

If anyone knows and could tell me if this type of boiler is "fully
modulating" it would be much appreciated

Thanks & Regards

Gaffar

Could someone please explain what a fully modulating combination
boiler is,

A fully modulating boiler is one that can vary the heat output according to
demand. A combination boiler is one that incorporates a hot water system to
supply taps. Most combi boilers are of the instantaneous type.

It is essential for sane operation that such instantaneous combis are fully
modulating. Otherwise, turning the tap down will cause the temperature to
rise until the boiler decides it needs to cut out, turning the water cold. A
fully modulating type will just turn down the gas to keep the temperature at
the set point.

Christian.

"Christian McArdle" wrote in message
. net...
Could someone please explain what a fully modulating combination
boiler is,

A fully modulating boiler is one that can
vary the heat output according to
demand.

Not quite. Some do. Some modulate down to maintain a flow temperature
stetpoint, which may not be quite in synch with demand.

Christian McArdle wrote:

Could someone please explain what a fully modulating combination
boiler is,

A fully modulating boiler is one that can vary the heat output according to
demand. A combination boiler is one that incorporates a hot water system to
supply taps. Most combi boilers are of the instantaneous type.

It is essential for sane operation that such instantaneous combis are fully
modulating. Otherwise, turning the tap down will cause the temperature to
rise until the boiler decides it needs to cut out, turning the water cold. A
fully modulating type will just turn down the gas to keep the temperature at
the set point.

Christian.

Thanks for the simple explanation, the concept is at least understood
now.

I have finally received the installation ans servicing manual from
Vaillant and in it, although there is nothing explicit which says that
it is fully modulating, there is a section for fault finding of which 1
sheet is headed "check burner modulation" would this indicate that this
boiler is fully modulated, or am I way off the mark

Thanks for the replies.

Regards
Gaffar

On Wed, 12 Jan 2005 22:34:49 +0000, Gaffar wrote:

Christian McArdle wrote:

Could someone please explain what a fully modulating combination
boiler is,

A fully modulating boiler is one that can vary the heat output according to
demand. A combination boiler is one that incorporates a hot water system to
supply taps. Most combi boilers are of the instantaneous type.

It is essential for sane operation that such instantaneous combis are fully
modulating. Otherwise, turning the tap down will cause the temperature to
rise until the boiler decides it needs to cut out, turning the water cold. A
fully modulating type will just turn down the gas to keep the temperature at
the set point.

Christian.

Thanks for the simple explanation, the concept is at least understood
now.

I have finally received the installation ans servicing manual from
Vaillant and in it, although there is nothing explicit which says that
it is fully modulating, there is a section for fault finding of which 1
sheet is headed "check burner modulation" would this indicate that this
boiler is fully modulated, or am I way off the mark


I'm nigh on certain that all Vaillant combis are modulating.
I think there may be some very early Vokeras which aren't.

--
Ed Sirett - Property maintainer and registered gas fitter.
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