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  #1   Report Post  
Wainscotting
 
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Default Vaillant Combi Boiler

When heating is on it takes an age to draw hot water. The diaphragm is new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


  #2   Report Post  
andrewpreece
 
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"Wainscotting" wrote in message
...
When heating is on it takes an age to draw hot water. The diaphragm is new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


I'm no expert but I've an idea what it is. It's a 242 right? There is a
valve/actuator thingy fairly central behind the panel. There is a pressure
activated lever emerging from it, which should actuate a red microswitch
within a few seconds, but it takes ages on knackered actuators, and you can
watch this lever arm inching slowly towards the microswitch. You won't get
hot water until it activates the microswitch, I suspect you're waiting 30-45
seconds for water? Sorry not to be technically accurate, others may give
a better explanationj, but have a look with the panel off, identify the
actuator/lever/microswitch assembly then get someone to turn on the hot tap
and see how long it takes to work. Solution? Probably get a new atuator
assembly, it may be all corroded/scaled up anyway.

PS. If you search for uk.d-i-y on Google ( search for 'Google groups' using
the options provided on Google's page ) you will get the uk.d-i-y archive,
and youcan search within this for more info on this problem, it has come up
within the last year at least once I believe.

Andy.


  #3   Report Post  
Wainscotting
 
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"andrewpreece" wrote in message
...

"Wainscotting" wrote in message
...
When heating is on it takes an age to draw hot water. The diaphragm is

new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


I'm no expert but I've an idea what it is. It's a 242 right? There is a
valve/actuator thingy fairly central behind the panel. There is a pressure
activated lever emerging from it, which should actuate a red microswitch
within a few seconds, but it takes ages on knackered actuators, and you

can
watch this lever arm inching slowly towards the microswitch. You won't get
hot water until it activates the microswitch, I suspect you're waiting

30-45
seconds for water? Sorry not to be technically accurate, others may give
a better explanationj, but have a look with the panel off, identify the
actuator/lever/microswitch assembly then get someone to turn on the hot

tap
and see how long it takes to work. Solution? Probably get a new atuator
assembly, it may be all corroded/scaled up anyway.

PS. If you search for uk.d-i-y on Google ( search for 'Google groups'

using
the options provided on Google's page ) you will get the uk.d-i-y archive,
and youcan search within this for more info on this problem, it has come

up
within the last year at least once I believe.

Andy.


Tanks for the reply Andy. It is actually a VCW T3W (either 20/1, 25/1 or
18). I will investigate tomorrow and see if I can locate the parts you
mention. Thanks for the Google archive info as well.


  #4   Report Post  
Ed Sirett
 
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Default

On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm is new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


  #5   Report Post  
Wainscotting
 
Posts: n/a
Default


"Ed Sirett" wrote in message
news
On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm is

new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Thanks Ed. I will have a llok in my instalation manual to try and locate it
(and the microswitch mentioned in Andy's post).




  #6   Report Post  
andrewpreece
 
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Default


"Wainscotting" wrote in message
...

"Ed Sirett" wrote in message
news
On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm is

new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).


Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Thanks Ed. I will have a llok in my instalation manual to try and locate

it
(and the microswitch mentioned in Andy's post).


If it's not a 242 then disregard what I said - I had a 242 and it had the
same
symptoms as your combi, but I have no idea what your combi looks like
inside, unless Vaillant use a largely common design. Ed Sirrett is a
professional and has more of an idea than I do!

Andy.


  #7   Report Post  
Wainscotting
 
Posts: n/a
Default


"andrewpreece" wrote in message
...

"Wainscotting" wrote in message
...

"Ed Sirett" wrote in message
news
On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm

is
new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).

Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Thanks Ed. I will have a llok in my instalation manual to try and locate

it
(and the microswitch mentioned in Andy's post).


If it's not a 242 then disregard what I said - I had a 242 and it had the
same
symptoms as your combi, but I have no idea what your combi looks like
inside, unless Vaillant use a largely common design. Ed Sirrett is a
professional and has more of an idea than I do!

Andy.


No problem - appreciate the reply


  #8   Report Post  
Ed Sirett
 
Posts: n/a
Default

On Wed, 13 Oct 2004 22:09:13 +0100, andrewpreece wrote:


"Wainscotting" wrote in message
...

"Ed Sirett" wrote in message
news
On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm is

new
so what else could be the cause? The boiler is about 15-20 years old
(VWSine).

Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Thanks Ed. I will have a llok in my instalation manual to try and locate

it
(and the microswitch mentioned in Andy's post).


If it's not a 242 then disregard what I said - I had a 242 and it had the
same
symptoms as your combi, but I have no idea what your combi looks like
inside, unless Vaillant use a largely common design. Ed Sirrett is a
professional and has more of an idea than I do!


Vaillants of this era are somewhat unique in their design features.
I am very familiar with 242s this is a slightly earlier model called a
Sine.
It could be the diverter valve and the HW performance is still there
at a reduced level
because some water goes through the secondary heat exchanger.
I rather assumed this might be the case.

This model has a cold/hot standby switch (this can make the difference of
around 30 seconds for hot HW to arrive at the tap). It might be that the
switch or some of the control gear has turned off this facility.

As you rightly say the DHW flow sensor whilst newly diaphragmed is sticky
in some other way (this can certainly happen on 242s - but I don't know
whether it's the same kit on Sines).


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


  #9   Report Post  
Wainscotting
 
Posts: n/a
Default


"Ed Sirett" wrote in message
news
On Wed, 13 Oct 2004 22:09:13 +0100, andrewpreece wrote:


"Wainscotting" wrote in message
...

"Ed Sirett" wrote in message
news On Thu, 14 Oct 2004 16:36:26 +0100, Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm

is
new
so what else could be the cause? The boiler is about 15-20 years

old
(VWSine).

Failed diverter valve.
The diaphragm you refer to is presumably the HW flow sensor?
I think they are sub £70 quid.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Thanks Ed. I will have a llok in my instalation manual to try and

locate
it
(and the microswitch mentioned in Andy's post).


If it's not a 242 then disregard what I said - I had a 242 and it had

the
same
symptoms as your combi, but I have no idea what your combi looks like
inside, unless Vaillant use a largely common design. Ed Sirrett is a
professional and has more of an idea than I do!


Vaillants of this era are somewhat unique in their design features.
I am very familiar with 242s this is a slightly earlier model called a
Sine.
It could be the diverter valve and the HW performance is still there
at a reduced level
because some water goes through the secondary heat exchanger.
I rather assumed this might be the case.

This model has a cold/hot standby switch (this can make the difference of
around 30 seconds for hot HW to arrive at the tap). It might be that the
switch or some of the control gear has turned off this facility.

As you rightly say the DHW flow sensor whilst newly diaphragmed is sticky
in some other way (this can certainly happen on 242s - but I don't know
whether it's the same kit on Sines).


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


Even in the summer I have to keep the radiator switch in the on position and
shut off all the radiator thermostats, plus, keep the cold/hot standby
switchin the "instant" position if I am to guarantee hot water. This time of
the year, with the heating on, if hot water is coming out of the tap and I
turn the cold/hot standby switch into the other position (not instant) the
boiler will shut off.
To recap....in the summer with the rad switch off I can't get any hot water
(most of the time). With the rad switch on I only get hot water if the
standby switch is in the "instant" position. With the heating on, hot water
takes up to 5 mins to come out of the tap and only then, with the standby
switch in the "instant" position. I will never get hot water if the standby
switch is not in the "instant" position. Perhaps it's time for a new boiler?


  #10   Report Post  
Paul King
 
Posts: n/a
Default

Wainscotting wrote:
When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).


I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler 'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the "silver
tank" which is the DHW heat exchanger. As another poster has said, the DHW
flow switch operates a couple of microswitches which fire up the boiler when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount of
WD40 at the point where the rod comes out of the flow switch body. You can
get a pair of pliers onto the bar and move it up and down to get the WD40 to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

HTH
--

Reply address is spamtrapped. Remove theobvious for valid e-mail address




  #11   Report Post  
Wainscotting
 
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Default


"Paul King" wrote in message
news:1097786351.2BWD3IA2pSU1qusXQkAzqQ@teranews...
Wainscotting wrote:
When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).


I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler

'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the

"silver
tank" which is the DHW heat exchanger. As another poster has said, the DHW
flow switch operates a couple of microswitches which fire up the boiler

when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount

of
WD40 at the point where the rod comes out of the flow switch body. You can
get a pair of pliers onto the bar and move it up and down to get the WD40

to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

HTH
--

Reply address is spamtrapped. Remove theobvious for valid e-mail address


Yep..that's the boiler. I will have a look at what you suggest tomorrow.
Thanks.


  #12   Report Post  
raden
 
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Default

In message 1097786351.2BWD3IA2pSU1qusXQkAzqQ@teranews, Paul King
writes
Wainscotting wrote:
When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).


I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler 'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the "silver
tank" which is the DHW heat exchanger. As another poster has said, the DHW
flow switch operates a couple of microswitches which fire up the boiler when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount of
WD40 at the point where the rod comes out of the flow switch body. You can
get a pair of pliers onto the bar and move it up and down to get the WD40 to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

WD40 really isn't the best long term fix

I would suggest silicone grease, until someone else picks me up on this
--
geoff
  #13   Report Post  
IMM
 
Posts: n/a
Default


"raden" wrote in message
...
In message 1097786351.2BWD3IA2pSU1qusXQkAzqQ@teranews, Paul King
writes
Wainscotting wrote:
When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).


I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler

'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the

"silver
tank" which is the DHW heat exchanger. As another poster has said, the

DHW
flow switch operates a couple of microswitches which fire up the boiler

when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount

of
WD40 at the point where the rod comes out of the flow switch body. You

can
get a pair of pliers onto the bar and move it up and down to get the WD40

to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

WD40 really isn't the best long term fix

I would suggest silicone grease, until someone else picks me up on this


Maxie, you are right. WD40 is a water repellent NOT a lubricant.


  #14   Report Post  
Paul King
 
Posts: n/a
Default

IMM wrote:
"raden" wrote in message
...
In message 1097786351.2BWD3IA2pSU1qusXQkAzqQ@teranews, WD40 really

isn't the best long term fix

I would suggest silicone grease, until someone else picks me up on
this


Maxie, you are right. WD40 is a water repellent NOT a lubricant.


I'm not disagreeing with either of you - just telling what I did. I used the
WD40 not to lube the actuator rod, but as a solvent to dissolve all of the
crud and gunge which had accumulated through time.

It worked, and I never had any more problems in the further 13 years I lived
at the house.
--

Reply address is spamtrapped. Remove theobvious for valid e-mail address


  #15   Report Post  
Ed Sirett
 
Posts: n/a
Default

On Fri, 15 Oct 2004 15:15:18 +0100, Paul King wrote:



It worked, and I never had any more problems in the further 13 years I lived
at the house.


.... further 13 years... we'd see a Puma,Ocean,Wickes etc. put in and
removed during that time.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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




  #16   Report Post  
raden
 
Posts: n/a
Default

In message , IMM writes

"raden" wrote in message
...
In message 1097786351.2BWD3IA2pSU1qusXQkAzqQ@teranews, Paul King
writes
Wainscotting wrote:
When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).

I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler

'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the

"silver
tank" which is the DHW heat exchanger. As another poster has said, the

DHW
flow switch operates a couple of microswitches which fire up the boiler

when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount

of
WD40 at the point where the rod comes out of the flow switch body. You

can
get a pair of pliers onto the bar and move it up and down to get the WD40

to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

WD40 really isn't the best long term fix

I would suggest silicone grease, until someone else picks me up on this


Maxie, you are right. WD40 is a water repellent NOT a lubricant.

Of course

--
geoff
  #17   Report Post  
P.R.Brady
 
Posts: n/a
Default

Paul King wrote:
Wainscotting wrote:

When heating is on it takes an age to draw hot water. The diaphragm
is new so what else could be the cause? The boiler is about 15-20
years old (VWSine).



I used to have a Vaillant VCW25 Sine which did this!
If yours is this type, You'll need to take off the front door, boiler 'stat
knob, front panel and left hand side panel to get at the DHW flow switch,
which is at the rear of the boiler, low down on the left, behind the "silver
tank" which is the DHW heat exchanger. As another poster has said, the DHW
flow switch operates a couple of microswitches which fire up the boiler when
hot water (tap) is required.

In my case, the actuator rod had become very stiff through time and was
hardly moving - thus no hot water. I cured it by squirting a small amount of
WD40 at the point where the rod comes out of the flow switch body. You can
get a pair of pliers onto the bar and move it up and down to get the WD40 to
do its stuff. I then cleaned all the gunge off with paper towels, and a
final short squirt of WD40 again. Never had any more problems after that.

HTH


Had this about 6 months ago and replaced the flow switch. I could not
find a 'repair kit' though it looks a doddle to refurbish if I'd been
able to do so. I got a new switch for around £105.

You could test whether it's a sluggish flow switch by removing the front
cover, the cover of the switch box and lifting the switches with a long
insulated screwdriver. It should fire up immediately.

Phil.

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