Viessmann Combi
 

A friend (as in the Flue question) has had a combi fitted upstairs (new flue
through roof). The fitter did a great job, but the electrician needs to come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control. However, what is the noise - is it a fan?

Viessmann Combi
 

In article ,
"John" writes:
A friend (as in the Flue question) has had a combi fitted upstairs (new flue
through roof). The fitter did a great job, but the electrician needs to come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control.

Shouldn't cause any problems -- boilers have to survive the
occasional power cut. I wouldn't switch it off this way too
often when the burners are alight though, as it may cause
localised boiling and overheating of the heat exchanger
when the pump suddenly stops.

However, what is the noise - is it a fan?

Um, how could we possibly tell?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Viessmann Combi
 

In article ,
John wrote:
A friend (as in the Flue question) has had a combi fitted upstairs (new
flue through roof). The fitter did a great job, but the electrician
needs to come in 2 weeks after my friend returns from holiday -
therefore it is running without a room stat at present.

No problem - if it's like mine. It comes with the thermostat wiring
bypassed anyway.

He is concerned about the noise and some of his family have switched it
off at the spur unit. My instinct is that this is a bad idea as it
could upset the pump or fan control. However, what is the noise - is it
a fan?

You can hardly hear mine at all with the cover on. Apart from when it
first starts - I think it blows air fast though the flue to make sure
there is no gas in there. But it's not a combi.
The electronics are fine if you power down completely - it will remember
all the settings.

--
*Why can't women put on mascara with their mouth closed?

Dave Plowman London SW
To e-mail, change noise into sound.

Viessmann Combi
 

On 31 Aug 2008 13:37:32 GMT, (Andrew
Gabriel) wrote:

In article ,
"John" writes:
A friend (as in the Flue question) has had a combi fitted upstairs (new flue
through roof). The fitter did a great job, but the electrician needs to come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control.

Shouldn't cause any problems -- boilers have to survive the
occasional power cut. I wouldn't switch it off this way too
often when the burners are alight though, as it may cause
localised boiling and overheating of the heat exchanger
when the pump suddenly stops.

That's interesting. The fan failed on my 3 year old WB combi boiler,
which I discovered immediately when I returned from holiday. The
engineer (one from WB) told me not to switch it off *ever* at the main
switch since the boiler needs to perform self tests every 24 hours and
(the switching off) may have caused the premature fan failure.

I'm not saying I believe him. I am just reporting this since the WB
engineer *should* know what he is talking about.

--
(\__/) M.
(='.'=) Owing to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking most articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.
See http://improve-usenet.org

Viessmann Combi
 

In article ,
Mark wrote:
That's interesting. The fan failed on my 3 year old WB combi boiler,
which I discovered immediately when I returned from holiday. The
engineer (one from WB) told me not to switch it off *ever* at the main
switch since the boiler needs to perform self tests every 24 hours and
(the switching off) may have caused the premature fan failure.

I'm not saying I believe him. I am just reporting this since the WB
engineer *should* know what he is talking about.

I'd agree with him - although not necessarily word for word. My Viessmann
runs the pump for a short time every 24 hours even with heating and water
heating shut down to prevent it seizing. There is a standby button to
achieve this state as well as a normal mains isolator on the boiler.

--
*Always drink upstream from the herd *

Dave Plowman London SW
To e-mail, change noise into sound.

Viessmann Combi
 

On Mon, 01 Sep 2008 14:50:20 +0100, "Dave Plowman (News)"
wrote:

In article ,
Mark wrote:
That's interesting. The fan failed on my 3 year old WB combi boiler,
which I discovered immediately when I returned from holiday. The
engineer (one from WB) told me not to switch it off *ever* at the main
switch since the boiler needs to perform self tests every 24 hours and
(the switching off) may have caused the premature fan failure.

I'm not saying I believe him. I am just reporting this since the WB
engineer *should* know what he is talking about.

I'd agree with him - although not necessarily word for word. My Viessmann
runs the pump for a short time every 24 hours even with heating and water
heating shut down to prevent it seizing. There is a standby button to
achieve this state as well as a normal mains isolator on the boiler.

Why should the fan be liable to seizing up when not in use unless it's
faulty? After all the fan is not use for quite a while between
manufacture and installation.

--
(\__/) M.
(='.'=) Owing to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking most articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.
See http://improve-usenet.org

Viessmann Combi
 

In article ,
Mark wrote:
On Mon, 01 Sep 2008 14:50:20 +0100, "Dave Plowman (News)"
wrote:

In article ,
Mark wrote:
That's interesting. The fan failed on my 3 year old WB combi boiler,
which I discovered immediately when I returned from holiday. The
engineer (one from WB) told me not to switch it off *ever* at the main
switch since the boiler needs to perform self tests every 24 hours and
(the switching off) may have caused the premature fan failure.

I'm not saying I believe him. I am just reporting this since the WB
engineer *should* know what he is talking about.

I'd agree with him - although not necessarily word for word. My
Viessmann runs the pump for a short time every 24 hours even with
heating and water heating shut down to prevent it seizing. There is a
standby button to achieve this state as well as a normal mains isolator
on the boiler.

Why should the fan be liable to seizing up when not in use unless it's
faulty? After all the fan is not use for quite a while between
manufacture and installation.

That's why I said I didn't agree with him word for word. But do with the
principle of leaving the boiler powered up - if it needs it. The
installation instructions should make it clear whether this is needed.

--
*If I throw a stick, will you leave?

Dave Plowman London SW
To e-mail, change noise into sound.

Viessmann Combi
 

On Sun, 31 Aug 2008 14:23:45 +0100, "John"
wrote:

A friend (as in the Flue question) has had a combi fitted upstairs (new flue
through roof). The fitter did a great job, but the electrician needs to come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control. However, what is the noise - is it a fan?

It could be the pump. As the thermostatic valves on the radiators
close, the pump faces increased resistance (or something). It will
start off quiet and get louder as the house heats up if this is the
case.

The thermostat circuit could be low voltage in which case you could do
it yourself:)

Viessmann Combi
 

"Keith2.0" wrote in message
...
On Sun, 31 Aug 2008 14:23:45 +0100, "John"
wrote:

A friend (as in the Flue question) has had a combi fitted upstairs (new
flue
through roof). The fitter did a great job, but the electrician needs to
come
in 2 weeks after my friend returns from holiday - therefore it is running
without a room stat at present.

He is concerned about the noise and some of his family have switched it
off
at the spur unit. My instinct is that this is a bad idea as it could upset
the pump or fan control. However, what is the noise - is it a fan?

It could be the pump. As the thermostatic valves on the radiators
close, the pump faces increased resistance (or something). It will
start off quiet and get louder as the house heats up if this is the
case.

The thermostat circuit could be low voltage in which case you could do
it yourself:)

He was running it with only DHW selected. His son got up in the middle of
the night to switch it off due to the new noise in the house.

Viessmann Combi
 

In article ,
Keith2.0 wrote:
On Sun, 31 Aug 2008 14:23:45 +0100, "John"
wrote:

A friend (as in the Flue question) has had a combi fitted upstairs (new
flue through roof). The fitter did a great job, but the electrician
needs to come in 2 weeks after my friend returns from holiday -
therefore it is running without a room stat at present.

He is concerned about the noise and some of his family have switched it
off at the spur unit. My instinct is that this is a bad idea as it
could upset the pump or fan control. However, what is the noise - is
it a fan?

It could be the pump. As the thermostatic valves on the radiators close,
the pump faces increased resistance (or something). It will start off
quiet and get louder as the house heats up if this is the case.

Assuming a modern Viessmann (I only have details of my one) the pump is a
vary speed unit so will adjust. It also has a built in bypass loop.

The thermostat circuit could be low voltage in which case you could do
it yourself:)

Mine uses a room temperature sensor rather than a thermostat. So all
adjustments are done from the programmer. But it has the option to use a
conventional one.

--
*Warning: Dates in Calendar are closer than they appear.

Dave Plowman London SW
To e-mail, change noise into sound.

Viessmann Combi
 

On Mon, 01 Sep 2008 19:23:35 +0100, "Dave Plowman (News)"
wrote:

In article ,
Mark wrote:
On Mon, 01 Sep 2008 14:50:20 +0100, "Dave Plowman (News)"
wrote:

In article ,
Mark wrote:
That's interesting. The fan failed on my 3 year old WB combi boiler,
which I discovered immediately when I returned from holiday. The
engineer (one from WB) told me not to switch it off *ever* at the main
switch since the boiler needs to perform self tests every 24 hours and
(the switching off) may have caused the premature fan failure.

I'm not saying I believe him. I am just reporting this since the WB
engineer *should* know what he is talking about.

I'd agree with him - although not necessarily word for word. My
Viessmann runs the pump for a short time every 24 hours even with
heating and water heating shut down to prevent it seizing. There is a
standby button to achieve this state as well as a normal mains isolator
on the boiler.

Why should the fan be liable to seizing up when not in use unless it's
faulty? After all the fan is not use for quite a while between
manufacture and installation.

That's why I said I didn't agree with him word for word. But do with the
principle of leaving the boiler powered up - if it needs it. The
installation instructions should make it clear whether this is needed.

The user and the installation instructions make no mention of leaving
the boiler switched on.

I must admit to being confused here. Either there is a risk of
seizure to the fan if switched off and therefore it must be left on or
there is little/no risk and hence it does not matter whether it is
left on or not?

--
(\__/) M.
(='.'=) Owing to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking most articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.
See http://improve-usenet.org

Viessmann Combi
 

On Sun, 31 Aug 2008 14:23:45 +0100, John wrote:

A friend (as in the Flue question) has had a combi fitted upstairs (new
flue through roof). The fitter did a great job, but the electrician
needs to come in 2 weeks after my friend returns from holiday -
therefore it is running without a room stat at present.

He is concerned about the noise and some of his family have switched it
off at the spur unit. My instinct is that this is a bad idea as it could
upset the pump or fan control. However, what is the noise - is it a fan?

There are two sources of noise the combustion fan and the circulator.
When on standby these may operate.

Most modern boilers seem to have an anti pump seize feature. Some pumps
when they get older can seize up if they are left for several months.
Once a day is probably OTT to ensure that the pump does not seize but
IMHO it must add some reliability. Older systems where the pump is only
used for the CH did have a habit of seizing over the summer.

However the most likely cause of significant noises from a combi when not
in use is some sort of warm standby mode. It might also be that the
customer has not been fully informed about the way the boiler works
etc.etc. And are inclined to believe that off should mean off and are
thus concerned about the noises.


I'm unaware if any boiler has an anti seize feature for the combustion
fan, these rarely seize, in my experience, anyway, so far.

In general the only boiler that I know of made in the last 15 years which
was intended not to be connected to the mains 24/7 was spit the baxi
barceona. A number of features require permanent power

Frost Protection
Built in time clocks.
Anti seize feature.
Warm stand by feature.




--
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
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

Viessmann Combi
 

In message , Ed Sirett
writes

I'm unaware if any boiler has an anti seize feature for the combustion
fan, these rarely seize, in my experience, anyway, so far.

because pumps can seize by scaling on the shaft - a quick flick keeps
this at bay

fans seize when the bearings have come to the end of their life
dead jim

--
geoff