Trying to help a friend remotely with this symptom of an Ariston boiler:

"Is displaying a fault which my handbook says could be due to low water
pressure, and to increase the water inlet coming in to it... where might
this inlet be? The boiler is coming on, getting to a certain temp
(varies) then closing down."

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

thx
E.

On 16/06/2012 20:25, eastender wrote:
Trying to help a friend remotely with this symptom of an Ariston boiler:

"Is displaying a fault which my handbook says could be due to low water
pressure, and to increase the water inlet coming in to it... where might
this inlet be? The boiler is coming on, getting to a certain temp
(varies) then closing down."

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

thx
E.
Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.

--
David

On 16/06/2012 20:28, gremlin_95 wrote:
On 16/06/2012 20:25, eastender wrote:
Trying to help a friend remotely with this symptom of an Ariston boiler:

"Is displaying a fault which my handbook says could be due to low water
pressure, and to increase the water inlet coming in to it... where might
this inlet be? The boiler is coming on, getting to a certain temp
(varies) then closing down."

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

thx
E.
Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.


I've never quite understood why all boilers seem to require manual
intervention to repressurise them. No system is perfect - they'll all
lose some water by some means or other. Back in the good old days all
hot water came from a cylinder and all heating water was circulated in a
loop that was constantly fed at gravity pressure by a header tank that
rather nicely took care of everything.

Now you have to turn two stupid little taps after you discover, on a
cold winter's morning, that the central heating never came on two hours
ago as it was supposed to and that the bath the children had the night
before means that there's no hot water for your morning shower...

Why is a safe and reasonably fool-proof automatic pressurising not
possible at a sufficiently marginal expense to the average boiler?

Michael

On 16/06/2012 20:38, Michael Kilpatrick wrote:

I've never quite understood why all boilers seem to require manual
intervention to repressurise them. No system is perfect - they'll all
lose some water by some means or other. Back in the good old days all
hot water came from a cylinder and all heating water was circulated in
a loop that was constantly fed at gravity pressure by a header tank
that rather nicely took care of everything.

Now you have to turn two stupid little taps after you discover, on a
cold winter's morning, that the central heating never came on two
hours ago as it was supposed to and that the bath the children had the
night before means that there's no hot water for your morning shower...

Why is a safe and reasonably fool-proof automatic pressurising not
possible at a sufficiently marginal expense to the average boiler?

Michael


I guess it helps you to pick up faults before they get worse, things
like leaky PRVs, pinhole leaks, failing expansion vessels etc. FWIW
though, I only have to increase the pressure slightly every year on my
system.

I have seen commercial systems with automatic re-pressurising though...

--
David

On Sat, 16 Jun 2012 20:38:07 +0100, Michael Kilpatrick
wrote:

Why is a safe and reasonably fool-proof automatic pressurising not
possible at a sufficiently marginal expense to the average boiler?

Lazy or thoughtless *******s just leave the valve open and the fill
pressure pre-set to 1bar.
I've seen the downsides of that one.

In article ,
gremlin_95 wrote:


think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.

Thanks * I presume she should leave the boiler electrics on but turn the
thermo down to cool it for a bit if it's been on?

E.

On 16/06/2012 20:28, gremlin_95 wrote:
On 16/06/2012 20:25, eastender wrote:
Trying to help a friend remotely with this symptom of an Ariston boiler:

"Is displaying a fault which my handbook says could be due to low water
pressure, and to increase the water inlet coming in to it... where might
this inlet be? The boiler is coming on, getting to a certain temp
(varies) then closing down."

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

thx
E.
Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.


But if the system is losing pressure, there's an underlying problem
which needs to be fixed. Re-pressurising it may work in the short term,
but the symptoms will return.
--
Cheers,
Roger
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checked.

On 16/06/2012 21:35, Roger Mills wrote:


But if the system is losing pressure, there's an underlying problem
which needs to be fixed. Re-pressurising it may work in the short
term, but the symptoms will return.


Yes indeed, the OP should keep an eye on it once re-pressurised.

--
David

On 16/06/2012 21:20, eastender wrote:
In ,
wrote:

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...
Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.
Thanks * I presume she should leave the boiler electrics on but turn the
thermo down to cool it for a bit if it's been on?

E.
It will be fine if the heating hasn't been on, don't worry about turning
anything down.

--
David

On 16/06/2012 20:38, Michael Kilpatrick wrote:
On 16/06/2012 20:28, gremlin_95 wrote:
On 16/06/2012 20:25, eastender wrote:
Trying to help a friend remotely with this symptom of an Ariston boiler:

"Is displaying a fault which my handbook says could be due to low water
pressure, and to increase the water inlet coming in to it... where might
this inlet be? The boiler is coming on, getting to a certain temp
(varies) then closing down."

think it needs repressurisating - here's a pic below the unit:

http://www.flickr.com/photos/49435266@N05/7381312968

Which tap(s) need to be turned (slowly i think) - I'm thinking its the
ones for the flexible hose...

thx
E.
Yes open both the black taps slowly and then close them when the
pressure reaches approx 1.0 - 1.5 bar when the system is cold.


I've never quite understood why all boilers seem to require manual
intervention to repressurise them. No system is perfect - they'll all
lose some water by some means or other. Back in the good old days all
hot water came from a cylinder and all heating water was circulated in a
loop that was constantly fed at gravity pressure by a header tank that
rather nicely took care of everything.

Now you have to turn two stupid little taps after you discover, on a
cold winter's morning, that the central heating never came on two hours
ago as it was supposed to and that the bath the children had the night
before means that there's no hot water for your morning shower...

Why is a safe and reasonably fool-proof automatic pressurising not
possible at a sufficiently marginal expense to the average boiler?

Michael


Once a properly installed system has been bled a few times to get all
the air out, it should run for years on end without needing to be
re-pressurised. As you are doubtless aware, topping up is a discrete
operation, and you're supposed to disconnect the filling loop once
you've done it (although many people don't!)

I'm sure that automatic top-up is *possible* - but it's not *desirable*.
You would need a permanently connected filling loop (which is bad) plus
an electrically operated valve to let water in when required. If that
valve failed, you could potentially get the system pressurised to mains
pressure - resulting in constant water loss through the PRV. Even if an
auto top-up system worked properly, it would mask common problems like
expansion vessel failure, resulting in the constant replacement of the
system water - with loss of inhibitor, and introduction of air.

Apart from that, it's a good idea! g

Incidentally, the F&E tank on a vented system doesn't *always* take care
of everything. Usually, so little water is lost that the ball-valve
doesn't have to open for a very long time. If a leak does then occur, so
that a top-up is needed, chances are that the ball-valve will stuck
firmly shut!
--
Cheers,
Roger
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checked.

On 16/06/2012 21:17, Grimly Curmudgeon wrote:
On Sat, 16 Jun 2012 20:38:07 +0100, Michael Kilpatrick
wrote:

Why is a safe and reasonably fool-proof automatic pressurising not
possible at a sufficiently marginal expense to the average boiler?

Lazy or thoughtless *******s just leave the valve open and the fill
pressure pre-set to 1bar.

Some have a pressure pre-set, do they? But *not* also a top-up
management system? That sounds like the worst of both worlds!

Our Baxi just has two taps and a pressure guage, and topping up relies
solely on hand-eye co-ordination.

I've seen the downsides of that one.

Well, quite. But any system which is capable of an automatic top-up
should be able to give an indication (however rough) of the number of
times it's had to top itself up. And maybe give a visual warning that
someone passing by the boiler can spot, such as a highly visible red
light that latches on once a top-up has occurred, until somoene cancels
the warning thus absolving the boiler of further responsibility.

Once you have automatic repressurisation hardware
(electronically-controlled water valves) the complexity of the
management system is a trivial expense. I assume there's a
microcontroller of some sort in the boiler, as our Baxi gives various
coded error messages and temperature display on a 2-digit 7-segment
display. Therefore having a few lines of extra code which allows a
repressurisation to be activated, but only for a limited time (in order
not to continue spewing water somewhere in the house!) is a virtually
zero marginal cost to the entire development event for the boiler.
Having an even cleverer system which knows not to initiate a top-up
within an hour of a previous top-up again is also a fairly trivial
software solution which doesn't require additional hardwa
microcontrollers have clock systems and I think you can extend them to
be able to count a period of any arbitrary length, seconds hours or
millennia, possibly!

Put it this way: it took several goes for me eventually to find out
where the small leak in an insufficiently-tightened fitting in our (2yr
old) replacement heating system was. Only on the third occasion did it
leak a sufficient quantity of water such that rather than just dampen
the loft insulation wool it dripped through the ceiling and left a small
puddle of water in the hallway.

For us there was absolutely no benefit in having a shut-down scenario
and an enforced manual top-up. How many hours and/or hundreds of pounds
of labour would it have taken to find the tiny leak after the first
shut-down occurred? It might never have been found either visually or
through a pressure test, since the leak clearly only got triggered once
in a blue moon through whatever combination of events and environmental
conditions! The loft insulation could have dried before we found it,
too. We might as well have had a system which allowed the leak to show
itself *properly* and be done with it.

Michael

On 16/06/2012 21:53, Roger Mills wrote:

I'm sure that automatic top-up is *possible* - but it's not *desirable*.
You would need a permanently connected filling loop (which is bad) plus
an electrically operated valve to let water in when required. If that
valve failed, you could potentially get the system pressurised to mains
pressure - resulting in constant water loss through the PRV.

Of course. But all things fail. Even manually-operated taps. I'm
assuming that's why the boiler has two taps in series, so that you have
to open *both* to open the filler loop? Looking at my boiler, that's all
they appear to be: two taps in series. You can just as well have two
electrically-operated valves instead of one. You can also design valves
with integral microswitches to offer feedback to the control system to
indicate one or more possible fault conditions.

Even if an
auto top-up system worked properly, it would mask common problems like
expansion vessel failure, resulting in the constant replacement of the
system water - with loss of inhibitor, and introduction of air.

As I've just written in another post, you can make a clever control
system that eliminates the need for a boiler shut-down at the first
whiff of a problem, but which does alert the user. You could even have
an annoying piezzo-electric buzzer if you liked. Boilers have
microcontrollers in them. Once you've got an extra panel lamp, the
electrically-operated valves and the warning buzzer, anything else is
just a bit of software development that is a one-off marginal expense,
so the cleverness of the system is not a problem, only the additional
cost of the physical components.

For example, you could easily devise a system which doesn't top up more
than once every 24hrs. Or one which doesn't allow a top-up state to
persist for more than 20 seconds if the desired pressure is not reached,
to avoid pouring water out of a hole somewhere. That's just noddy
software, easy-peasy. Or one which will top-up once (with the 20-second
rule applying) but will not top-up again a second time until the user
resets the warning condition, thus handing responsibility to the user to
investigate further. With or without an annoying warning buzzer!

As I said in my other message, the shut-down state was of no use to me,
as it took several top-ups over 2 years to identify the mystery leak
which may have dribbled very slowly, but only after the third (?) top-up
did it spew out enough water in one go so as to be detectable by a
puddle on the hall floor and ruined paint on the hall ceiling. I needed
to know that something was wrong in the form of a slow or occasional
leak - but I didn't benefit from having no heating one winter morning!

All those things are easy - it only requires the willingness of the
home-owner to absorb the extra cost of the electrically-operated valves,
because the marginal cost of the software development is a negligible
one-off.


Michael

On 16/06/2012 22:46, Michael Kilpatrick wrote:

As I've just written in another post, you can make a clever control
system that eliminates the need for a boiler shut-down at the first
whiff of a problem, but which does alert the user. You could even have
an annoying piezzo-electric buzzer if you liked. Boilers have
microcontrollers in them. Once you've got an extra panel lamp, the
electrically-operated valves and the warning buzzer, anything else is
just a bit of software development that is a one-off marginal expense,
so the cleverness of the system is not a problem, only the additional
cost of the physical components.

I built a simple auto-fill system here at Lowe Towers.

It's basically a 1-bar Pressure Reducing Valve, and an electrically
operated solenoid in series.

The control system is trivial, it's a DIN-rail timer module.

When the heating comes on in the morning / afternoon, the switched live
to the boiler is intercepted at the timer module, and it activates the
solenoid for a 10-second fill-period. After 10 seconds, it times out
and drops over to fire the boiler.

So the system operates for typically 20 seconds a day: once at each 'on'
period from the CH timeclock, when thy system will be cold.

The timer / solenoid is there to prevent it feeding a major leak.

--
Ron

On 16/06/2012 22:46, Michael Kilpatrick wrote:


Of course. But all things fail. Even manually-operated taps. I'm
assuming that's why the boiler has two taps in series, so that you have
to open *both* to open the filler loop?

My belief is that the two taps are there so that the system remains
sealed when the flexible filling loop pipe is removed - as it is
supposed to be when not actively being used, in order to prevent
accidental over-pressurisation.
--
Cheers,
Roger
____________
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checked.

On 17/06/2012 09:02, Ron Lowe wrote:
On 16/06/2012 22:46, Michael Kilpatrick wrote:

As I've just written in another post, you can make a clever control
system that eliminates the need for a boiler shut-down at the first
whiff of a problem, but which does alert the user. You could even have
an annoying piezzo-electric buzzer if you liked. Boilers have
microcontrollers in them. Once you've got an extra panel lamp, the
electrically-operated valves and the warning buzzer, anything else is
just a bit of software development that is a one-off marginal expense,
so the cleverness of the system is not a problem, only the additional
cost of the physical components.

I built a simple auto-fill system here at Lowe Towers.

It's basically a 1-bar Pressure Reducing Valve, and an electrically
operated solenoid in series.

The control system is trivial, it's a DIN-rail timer module.

When the heating comes on in the morning / afternoon, the switched live
to the boiler is intercepted at the timer module, and it activates the
solenoid for a 10-second fill-period. After 10 seconds, it times out and
drops over to fire the boiler.

So the system operates for typically 20 seconds a day: once at each 'on'
period from the CH timeclock, when thy system will be cold.

The timer / solenoid is there to prevent it feeding a major leak.


My guess is that, even if it didn't feed a major leak, it would still
mask a partial failure of the expansion vessel. You'd pressurise at
start-up, the pressure would rise above 3.5bar when the system got hot,
and expel water through the PRV. The pressure would fall below 1 bar
when the system cooled - and be topped up by your automatic system at
next start-up. Twenty seconds would be sufficient for this, but you'd
soon lose all your inhibitor!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

Roger Mills wrote:
On 16/06/2012 22:46, Michael Kilpatrick wrote:


Of course. But all things fail. Even manually-operated taps. I'm
assuming that's why the boiler has two taps in series, so that you have
to open *both* to open the filler loop?

My belief is that the two taps are there so that the system remains
sealed when the flexible filling loop pipe is removed - as it is
supposed to be when not actively being used, in order to prevent
accidental over-pressurisation.

Or, as the rules state, possible back feed from the system into the
drinking water supply.

--
Tciao for Now!

John.

On 17/06/2012 09:02, Ron Lowe wrote:


I built a simple auto-fill system here at Lowe Towers.

It's basically a 1-bar Pressure Reducing Valve, and an electrically
operated solenoid in series.

The control system is trivial, it's a DIN-rail timer module.

When the heating comes on in the morning / afternoon, the switched live
to the boiler is intercepted at the timer module, and it activates the
solenoid for a 10-second fill-period. After 10 seconds, it times out and
drops over to fire the boiler.

So the system operates for typically 20 seconds a day: once at each 'on'
period from the CH timeclock, when thy system will be cold.

The timer / solenoid is there to prevent it feeding a major leak.



OK, but the system just blindly goes ahead and does it every morning if
it needs to. You're still pumping 10 seconds of water every day and the
user might be non the wiser as to what is going on. A slightly more
complex system would, as I described, not force a shut-down the very
second a pressure loss occurred, but neither would it blindly do a
top-up every day: it take a more analytical approach and make more
informed decisions, based on the number and frequency of the top-ups, as
to whether shutting down would be the more sensible thing to do rather
than just alerting the user and carrying on. That's why such analysis
should (and could) be done by the microcontroller/microprocessor that
already exists in the boiler.

Michael

On 17/06/2012 11:03, Roger Mills wrote:
On 17/06/2012 09:02, Ron Lowe wrote:

I built a simple auto-fill system here at Lowe Towers.


My guess is that, even if it didn't feed a major leak, it would still
mask a partial failure of the expansion vessel. You'd pressurise at
start-up, the pressure would rise above 3.5bar when the system got hot,
and expel water through the PRV. The pressure would fall below 1 bar
when the system cooled - and be topped up by your automatic system at
next start-up. Twenty seconds would be sufficient for this, but you'd
soon lose all your inhibitor!

Yes, it might mask that.
I do monitor the system hot pressure from time to time to see if it's
creeping over the usual 2.5 ish bar.

But the main reason I needed the auto-fill was that the system does have
a trivial leak ( it drops below the boiler's threshold over about 1-2
weeks ). I'm not prepared to rip up the flooring to find that.

And I *need* to be sure the system will come on when I'm away for
extended periods over the winter to avoid freezing.

That's the major driver here, and over-rides most other concerns.
The system as-designed does what I need.

--
R