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Fxed at last! My Wallstar 15/20 oil boiler is now working properly

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MM

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Dec 20, 2012, 2:49:25 AM12/20/12
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With the original spec DKO970 control box fitted (a new one, not the
actual original unit that was fitted when the boiler was brand new 9
years ago) we noticed that the fire valve was letting air in, tiny
amounts, tiny bubbles, every now and again. The transparent tube was
full for a while, then a few minutes later there'd be tiny little
bubbles appearing just where the tube is connected to the fire valve
and soon the entire tube was practically all air, the burner was
puffing like Puffing Billy and sending out puffs of smoke, whereupon
the engineer said "That's going to lock ou!" and lock out it did. Then
after locking out and reset pressed, the fuel started flowing again,
after a fashion, allowing the boiler to fire again, and this just went
on and on: Run for a few minutes -- air bubbles -- lockout --
recover.

However, the DKO970 seems much more sensitive than the TF 832.3 and
made valiant attempts to let the boiler fire, but kept on locking out
every few seconds. It was this that helped diagnose the fundamental
problem.

The engineer said it absolutely should NOT be like that, so he fitted
a new fire valve and pump. The old pump, well you cannot believe how
shagged it was. He got me to turn the shaft and it wasn't just tight
at one spot, it was practically rock solid! I held the pump in one
hand and turned the shaft with my other hand and I really had to
wrench the shaft past its tight spot. Bloody awful. I reckon the pump
bearings must have been running hot with a tight spot like that,
although how the motor and capacitor ever managed to start the pump
turning, beats me. But start it did. I reckon the problem was
compounded by the combination of the tight spot and the fire valve
leaking in air. Somehow, the pump and control gubbins made every
attempt to run, but that tight spot would nearly always be where the
pump came to rest when the boiler switched off.

He reckons that if the pump has been sucking air over several months,
even a year, it was pretty soon f***ed. The old fire valve was totally
shagged. Sucking on the "to pump" side of it (as if siphoning), one
could barely get anything through it. So maybe the pump, as the
problem worsened -- remember how I said it started in July then got
steadily worse, so that by October the lockouts were happening
practically every day? -- had been trying its damndest to suck oil
and so when air got in instead (through the duff fire valve) the pump
somehow kept going, but was literally pumping itself into an early
grave. With lack of a constant flow of fuel to lubricate itself, the
bearings started running hot and the tight spot developed.

As for the other parts fitted (motor, solenoid, photocell, oh, well,
at least they're not going to wear out any time soon! I'm just pleased
to have a working boiler again at long last. Of course, in hindsight
we should have checked the pump FIRST, but since it was only three
years old, we assumed it must be okay.

My engineer and I have come to an amicable arrangement which involves
draining and power flushing the system in the Spring and putting new
inhibitor in.

MM

harry

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Dec 20, 2012, 2:52:03 AM12/20/12
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If the pump shaft was worn, maybe air was being sucked in there. New
one on me though.

harry

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Dec 20, 2012, 2:53:54 AM12/20/12
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If the pump shaft was worn, maybe the air was being sucked in there.

Brian Gaff

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Dec 20, 2012, 3:55:07 AM12/20/12
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Three years? One might ask if there is something else making the flow less
than good making the pump die early?
I hate oil heating. I remember it at a place I stayed once, seemed to be
always on the blink..
Brian

--
From the Sofa of Brian Gaff Reply address is active
"MM" <kyli...@yahoo.co.uk> wrote in message
news:kme5d8p5h66r14pk0...@4ax.com...

Jim K

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Dec 20, 2012, 7:40:18 AM12/20/12
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like a gunged up tank filter?

Jim K


On Dec 20, 8:55 am, "Brian Gaff" <Bria...@blueyonder.co.uk> wrote:
> Three years? One might ask if there is something else making the flow less
> than good making the pump die early?
>  I hate oil heating. I remember it at a place I stayed once, seemed to be
> always on the blink..
> Brian
>
> --
> From the Sofa of Brian Gaff Reply address is  active"MM" <kylix...@yahoo.co.uk> wrote in message

MM

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Dec 20, 2012, 7:46:51 AM12/20/12
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Well, maybe through that route as well. But the fire valve was deffo
shagged.

MM

MM

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Dec 20, 2012, 7:52:49 AM12/20/12
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On Thu, 20 Dec 2012 08:55:07 -0000, "Brian Gaff"
<Bri...@blueyonder.co.uk> wrote:

>Three years? One might ask if there is something else making the flow less
>than good making the pump die early?

Yes, the air. If the pump was sucking in air bubbles intermittently
via the fire valve over a period of months, that could place severe
strain on the bearings if not properly lubricated. It may even have
been the case that the pump shaft was constantly coming to a stop
"dry" when the oil flow temporarily ceased and the boiler locked out,
thus causing excessive wear on the bearings.

> I hate oil heating. I remember it at a place I stayed once, seemed to be
>always on the blink..
>Brian

Well, yes, *now* I know! I lived with gas down south before moving up
here and the boiler ran for 23 years with never more than a
thermocouple every two - three years.

However, I asked the heating engineer whether it would be worth
switching to Calor Gas (there is no mains gas here), and he said
absolutely not. Heating oil has a far higher calorific value than
propane, pound for pound.

MM

MM

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Dec 20, 2012, 7:58:52 AM12/20/12
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On Thu, 20 Dec 2012 04:40:18 -0800 (PST), Jim K <jk98...@gmail.com>
wrote:

>like a gunged up tank filter?

Hardly. It was checked at the last service in March and checked again
this time. 'Twas the fire valve that was the culprit. The pump
desperately tried to keep going, sucked air intermittently, the pump
bearings overheated, the tight spot developed, thus giving rise to the
problem steadily worsening since July. Mweanwhile the capacitor
started giving up the ghost trying to start the pump across the tight
spot. Mostly, up to around October, the pump did start, but then
increasingly it failed to, and the lockouts occurred.

MM

Allan Mac

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Dec 20, 2012, 10:01:58 AM12/20/12
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On 20 Dec, 12:58, MM <kylix...@yahoo.co.uk> wrote:
> On Thu, 20 Dec 2012 04:40:18 -0800 (PST), Jim K <jk989...@gmail.com>
Pleased it's going, and you've got a few spares !!

Dave Liquorice

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Dec 20, 2012, 11:49:04 AM12/20/12
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On Thu, 20 Dec 2012 12:58:52 +0000, MM wrote:

>> like a gunged up tank filter?
>
> Hardly. It was checked at the last service in March and checked again
> this time.

Did I not suggest a complete strip down and check of flow for the entire
oil line a while back? That would have picked up the blocked fire
valve...

--
Cheers
Dave.



Dave Liquorice

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Dec 20, 2012, 11:44:42 AM12/20/12
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On Thu, 20 Dec 2012 08:55:07 -0000, Brian Gaff wrote:

> I hate oil heating. I remember it at a place I stayed once, seemed to
> be always on the blink..

Ours is fine, it's let us down twice in 12 years. Once was water freezing
in a low point in the supply line. Once was a sooted up photo cell.
Certainly seems more reliable than these highly complex and thus
unreliable gas condenser/combi jobbies, far more queries about bust gas
boilers in here than bust oil boilers... B-)

--
Cheers
Dave.



dennis@home

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Dec 20, 2012, 1:31:43 PM12/20/12
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That's quite poor, my gas boiler has had one failure in 32 years.
The gas valve stopped opening so it wouldn't fire.


MM

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Dec 20, 2012, 1:45:39 PM12/20/12
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Hindsight is a wunnerful thang!

MM
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