[Milsec]

I need to find someone in to look at this 3 year old boiler. IMO it has a sticky and/or defective divertor valve (see below for a list of symptoms).

I was wondering if anyone could recommend any good, reliable and fairly priced heating engineers in the NW London area?

Thanks all.


Fault description

1) Divertor valve sometimes makes a grinding noise as it moves position. (Has done that about 6 months after installation, but everything worked fine.)

2) No hot water on demand when heating is on sometimes,and radiators become very hot and boiler indicates (green light flashes) that that it is heating hot water for the hot tap even after hot tap has been closed and no hot tap is open.

This tends to happen usually when the central heating has been on (ie the boiler is fired up already and hot).
The condition persists even if the boiler is switched off at mains and then on again after say 10 -20 seconds. Turning the hot water temperature control knob to off and then on again can stop the green light flashing, but does not restore normal hot water delivery.

It seems divertor valve has seized when this happens.

Boiler has to be switched off at mains and left to cool down for some time (at least an hour or more) to restore normal operation.

There are times when the valve only partially opens because luke warm water comes out of the hot tap.

Recently the divertor valve has been know to stick from cold (first thing in the morning when heating is off.

3) Boiler goes into warm start mode during the night (when heating is off). Radiators get warm and boiler cycles on and off frequently (e.g. 2 mins on, 30-40 secs off). Boiler shows yellow light and flashing green -- no hot tap was opened when this occurs.

4) General performance of boiler is erratic.
There are constant pump overruns when the boiler switches off even though demanded temperature from the room stat has not been reached. And this happens when the boiler isn't in the fault mode described in 2) or 3).

Milsec wrote:

I was wondering if anyone could recommend any good, reliable and fairly
priced heating engineers in the NW London area?

Don't know of any, changed the valve on our 828e myself, it's very easy
to do on this boiler

Lee
--
Email address is valid, but is unlikely to be read.

In message , Milsec
writes

I need to find someone in to look at this 3 year old boiler. IMO it
has
a sticky and/or defective divertor valve (see below for a list of
symptoms).

I'm sure Ed Sirett will be along in a minute or two

--
geoff

[Milsec]

Originally Posted by Lee

Milsec wrote:

I was wondering if anyone could recommend any good, reliable and fairly
priced heating engineers in the NW London area?

Don't know of any, changed the valve on our 828e myself, it's very easy
to do on this boiler

Lee
--
Email address is valid, but is unlikely to be read.

Thanks Lee,

I may have had a go if the weather was milder, and may do if I still haven't found some one by then. Give us a few pointers then, especially about draining the system and making sure that you don't get water on the electronics box!
By the way did you have all of the symptoms I have especially the excessive pump overuns and funny warm-start behavior?

Milsec

Milsec wrote:

I may have had a go if the weather was milder, and may do if I still
haven't found some one by then. Give us a few pointers then, especially
about draining the system and making sure that you don't get water on
the electronics box!

Turn off the power first
All I did was close off the boiler shutoff valves and drained the water
from the boiler, carefully
(It's obviously not necessary to drain the whole system if using the
shutoff valves)
Others here have suggested not using the built in drain points on the
valves, as they may leak apparently, but they worked fine for me.
It is possible not to spill any on the PCB if you are careful, but
obviously protect it with something absorbent if you want.

The valve itself is easy, but don't forget to change the O rings, washer
and clip - it should come with new ones. Mine did.

By the way did you have all of the symptoms I have especially the
excessive pump overuns and funny warm-start behavior?

Yep Especially the warm start malarky, which I turned off because it
was aggravating the problem.
Like yours, the valve on ours was noisy from the start, but the new
valve is almost silent.

Got the valve he
http://www.ezypart.co.uk/parts/part_id__156
Seen them cheaper, but this place delivered next day

Lee
--
Email address is valid, but is unlikely to be read.

On Sun, 26 Feb 2006 01:01:23 +0000, Milsec wrote:


I need to find someone in to look at this 3 year old boiler. IMO it has
a sticky and/or defective divertor valve (see below for a list of
symptoms).

I was wondering if anyone could recommend any good, reliable and fairly
priced heating engineers in the NW London area?

Thanks all.


_Fault_description_

1) Divertor valve sometimes makes a grinding noise as it moves
position. (Has done that about 6 months after installation, but
everything worked fine.)

2) No hot water on demand when heating is on sometimes,and radiators
become very hot and boiler indicates (green light flashes) that that
it is heating hot water for the hot tap even after hot tap has been
closed and no hot tap is open.

This tends to happen usually when the central heating has been on
(ie the boiler is fired up already and hot).
The condition persists even if the boiler is switched off at mains and
then on again after say 10 -20 seconds. Turning the hot water
temperature control knob to off and then on again can stop the green
light flashing, but does not restore normal hot water delivery.

It seems divertor valve has seized when this happens.

Boiler has to be switched off at mains and left to cool down for some
time (at least an hour or more) to restore normal operation.

There are times when the valve only partially opens because luke warm
water comes out of the hot tap.

Recently the divertor valve has been know to stick from cold (first
thing in the morning when heating is off.

3) Boiler goes into warm start mode during the night (when heating is
off). Radiators get warm and boiler cycles on and off frequently (e.g.
2 mins on, 30-40 secs off). Boiler shows yellow light and flashing
green -- no hot tap was opened when this occurs.

4) General performance of boiler is erratic.
There are constant pump overruns when the boiler switches off even
though demanded temperature from the room stat has not been reached.
And this happens when the boiler isn't in the fault mode described in
2) or 3).

I think your diagnosis is quite correct.
You can switch off the warm start feature by turning the DHW control to
minimum and then back to the previous setting. The green light will
then only flash when a tap is running.

The diverter valve is £100 (available form A10 boiler spares and
doubtless online).

If you try to fix (rather than replace) the diverter it will fall apart
so don't try until you are ready.

Email me privately if you are prepared to wait a couple of weeks before I
can help. With care the job can be done without a full drain down.

--
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

On Sun, 26 Feb 2006 18:48:44 +0000, Lee wrote:

Milsec wrote:

I may have had a go if the weather was milder, and may do if I still
haven't found some one by then. Give us a few pointers then, especially
about draining the system and making sure that you don't get water on
the electronics box!

Turn off the power first
All I did was close off the boiler shutoff valves and drained the water
from the boiler, carefully
(It's obviously not necessary to drain the whole system if using the
shutoff valves)
Others here have suggested not using the built in drain points on the
valves, as they may leak apparently, but they worked fine for me.
It is possible not to spill any on the PCB if you are careful, but
obviously protect it with something absorbent if you want.

The valve itself is easy, but don't forget to change the O rings, washer
and clip - it should come with new ones. Mine did.

By the way did you have all of the symptoms I have especially the
excessive pump overuns and funny warm-start behavior?

Yep Especially the warm start malarky, which I turned off because it
was aggravating the problem.
Like yours, the valve on ours was noisy from the start, but the new
valve is almost silent.

Got the valve he
http://www.ezypart.co.uk/parts/part_id__156
Seen them cheaper, but this place delivered next day

I agree this is a straight forward job and the price online is a lot
better than the spares shop. I've never had any trouble with the boiler
isolators or drain off valves on this model.



--
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

[Milsec]

Ed, Lee thanks for the feedback.

Yes I've had a look at the valve (I hope it not soft brass, otherwise I'm definitely not touching it). But there has been some recent developments:

1) Warm start can't be tuned off anymore. Turning the water temperature knob to the left and back again still leaves the green light on.
2) Got an F.22 error. Very strange indeed since there was and is water in the system. I turned the boiler off, waited 10 secs and then powered on again and it worked as usual. Maybe it was crud in the system stalling the pump?

I'm hoping these are related to the valve sticking and out of sync states(?) and nothing more.

By the way, what is anti-cycling, and what does Part load setting (d.00) mean?

Regards.

On Tue, 28 Feb 2006 00:24:43 +0000, Milsec wrote:


Ed, Lee thanks for the feedback.

Yes I've had a look at the valve (I hope it not soft brass, otherwise
I'm definitely not touching it). But there has been some recent
developments:

1) Warm start can't be tuned off anymore. Turning the water temperature
knob to the left and back again still leaves the green light on.
2) Got an F.22 error. Very strange indeed since there was and is water
in the system. I turned the boiler off, waited 10 secs and then powered
on again and it worked as usual. Maybe it was crud in the system
stalling the pump?

I'm hoping these are related to the valve sticking and out of sync
states(?) and nothing more.

By the way, what is anti-cycling, and what does Part load setting
(d.00) mean?

Regards.

When you have fixed the diverter valve I suspect the other problems may
disappear. Note there is something of a detent at the end of the DHW
knob's range. Try giving turning it a little more a the lowest end.

Anti cycling is a delay imposed by the controller to reduce short cycling.
AFAIK the delay is the same whether it's from the internal or external
thermostat being satisfied, but it is temperature related (hotter makes
it shorter).

The parameter d.02 is a modifiable one which can be used to adjust the
anti-cycling delay.

The parameter d.00 is also adjustable and can be used to adjust the
maximum power of the burner in heating mode. It goes from 0 to 15 I expect
the 0 maps to the lowest setting i.e about 40% of full power.

HTH


--
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