Water has started to run slowly from the Overflow? The pressure gauge
onthe boiler is indicating approx 3bar. I have de-pressurised the
system and refilled to 1 bar bleed & bleed all raditors. The filling
key is removed.

Everything seemed ok but overnight the pressure rose again to 3 bar and
the overflow is running again.

This is not covered in the fault diagnosis provided? my guess is that
the water divering valve is faulty.

has anyone had experience of this fault.


--
MrMick

"MrMick" wrote in message
. ..

Water has started to run slowly from the Overflow? The pressure gauge
onthe boiler is indicating approx 3bar. I have de-pressurised the
system and refilled to 1 bar bleed & bleed all raditors. The filling
key is removed.

Everything seemed ok but overnight the pressure rose again to 3 bar and
the overflow is running again.

This is not covered in the fault diagnosis provided? my guess is that
the water divering valve is faulty.

has anyone had experience of this fault.


--
MrMick

I would bet that your 'water-to-water' plate heat exchanger has got a leak.
This is a twin chamber, one side of which contains the 'heated water' from
your boiler, the other half contains mains pressure water which goes off to
your hot tap. Turn on your hot tap, mains water goes through the plate heat
exchanger, gets hot, then comes out of your tap! If there is a leak between
the wall in the chamber, mains water (being of much higher pressure than 3
bar) will push its way into your heating circuit, thus raising the pressure.
Empty your pressure, turn off your boiler at the mains before you go to
work, if it has raised when you come home then the plate heat exchanger is
definitely your problem.

Easy to change, order yourself a pressure relief valve at the same time
though as this may continue to drip.

Angus

Fentoozler Wrote:
"MrMick" wrote in message
. ..

Water has started to run slowly from the Overflow? The pressure gauge
onthe boiler is indicating approx 3bar. I have de-pressurised the
system and refilled to 1 bar bleed & bleed all raditors. The filling
key is removed.

Everything seemed ok but overnight the pressure rose again to 3 bar
and
the overflow is running again.

This is not covered in the fault diagnosis provided? my guess is that
the water divering valve is faulty.

has anyone had experience of this fault.


--
MrMick

I would bet that your 'water-to-water' plate heat exchanger has got a
leak.
This is a twin chamber, one side of which contains the 'heated water'
from
your boiler, the other half contains mains pressure water which goes
off to
your hot tap. Turn on your hot tap, mains water goes through the plate
heat
exchanger, gets hot, then comes out of your tap! If there is a leak
between
the wall in the chamber, mains water (being of much higher pressure
than 3
bar) will push its way into your heating circuit, thus raising the
pressure.
Empty your pressure, turn off your boiler at the mains before you go
to
work, if it has raised when you come home then the plate heat exchanger
is
definitely your problem.

Easy to change, order yourself a pressure relief valve at the same
time
though as this may continue to drip.

Angus


Thanks,
Did that last night and after 2 hours pressure had increased to 2.5
bar.
looking at the connections inside the boiler I see that the cold supply
goes through the diverter valve to the heat exchanger, is it possible
for the leak to be in the diverter and is there any way of confirming
if its diverter or heat exchanger?

Mick


--
MrMick

"MrMick" wrote in message
. ..

Fentoozler Wrote:
"MrMick" wrote in message
. ..

Water has started to run slowly from the Overflow? The pressure gauge
onthe boiler is indicating approx 3bar. I have de-pressurised the
system and refilled to 1 bar bleed & bleed all raditors. The filling
key is removed.

Everything seemed ok but overnight the pressure rose again to 3 bar
and
the overflow is running again.

This is not covered in the fault diagnosis provided? my guess is that
the water divering valve is faulty.

has anyone had experience of this fault.


--
MrMick

I would bet that your 'water-to-water' plate heat exchanger has got a
leak.
This is a twin chamber, one side of which contains the 'heated water'
from
your boiler, the other half contains mains pressure water which goes
off to
your hot tap. Turn on your hot tap, mains water goes through the plate
heat
exchanger, gets hot, then comes out of your tap! If there is a leak
between
the wall in the chamber, mains water (being of much higher pressure
than 3
bar) will push its way into your heating circuit, thus raising the
pressure.
Empty your pressure, turn off your boiler at the mains before you go
to
work, if it has raised when you come home then the plate heat exchanger
is
definitely your problem.

Easy to change, order yourself a pressure relief valve at the same
time
though as this may continue to drip.

Angus


Thanks,
Did that last night and after 2 hours pressure had increased to 2.5
bar.
looking at the connections inside the boiler I see that the cold supply
goes through the diverter valve to the heat exchanger, is it possible
for the leak to be in the diverter and is there any way of confirming
if its diverter or heat exchanger?


The diverter will leak to atmosphere along the shaft not into the other wet
system