Noticed a small leak from my Vitodens 200 system boiler today. It's coming
from what appears to be a thermocouple (its a brass cylinder with a thin
copper tube going to the PCB) in the water return. What does that do?

I've been online to spares places to try and find it - although not
knowing what it's called doesn't help and I couldn't find any pics that
matched up.

Have to try and find the paperwork tomorrow.

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Dave Plowman London SW
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Seems it's a manometer. Presumably to work the gauge which shows the water
pressure?

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Dave Plowman London SW
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Dave Plowman (News) wrote:
Seems it's a manometer. Presumably to work the gauge which shows the water
pressure?

Possibly but as it goes to the PCB, it will measure the system pressure
and shut down the boiler if it falls below a prescribed limit.

If the pressure gauge is electronic, the same sensor might be used for
the display but otherwise a simple selef contained mechanical pressure
gauge is probably used for the display.

The term manometer is more associated with measuring gas pressures which
is not likely to be monitored by your boiler but also could be measuring
fan air pressure which will be monitored by the control system.

In article ,
Bob Minchin wrote:
Dave Plowman (News) wrote:
Seems it's a manometer. Presumably to work the gauge which shows the
water pressure?

Possibly but as it goes to the PCB, it will measure the system pressure
and shut down the boiler if it falls below a prescribed limit.

If the pressure gauge is electronic, the same sensor might be used for
the display but otherwise a simple selef contained mechanical pressure
gauge is probably used for the display.

The term manometer is more associated with measuring gas pressures which
is not likely to be monitored by your boiler but also could be measuring
fan air pressure which will be monitored by the control system.

A manometer is simply a device for measuring gas or liquid pressure.

In this case it pokes into the water return to the boiler, so I'd guess it
simply measures the water pressure - being a pressurized system. Won't
know if it cuts off the boiler if the pressure is too low until I change
it when the new one arrives on Monday. It's then I'll find all it needed
was a new O ring. ;-)

--
*If God had wanted me to touch my toes, he would have put them on my knees

Dave Plowman London SW
To e-mail, change noise into sound.

On Fri, 15 Feb 2013 17:26:43 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
Bob Minchin wrote:
Dave Plowman (News) wrote:
Seems it's a manometer. Presumably to work the gauge which shows the
water pressure?

Possibly but as it goes to the PCB, it will measure the system pressure
and shut down the boiler if it falls below a prescribed limit.

If the pressure gauge is electronic, the same sensor might be used for
the display but otherwise a simple selef contained mechanical pressure
gauge is probably used for the display.

The term manometer is more associated with measuring gas pressures which
is not likely to be monitored by your boiler but also could be measuring
fan air pressure which will be monitored by the control system.

A manometer is simply a device for measuring gas or liquid pressure.

Fluid pressure then.

In this case it pokes into the water return to the boiler, so I'd guess it
simply measures the water pressure - being a pressurized system. Won't
know if it cuts off the boiler if the pressure is too low until I change
it when the new one arrives on Monday. It's then I'll find all it needed
was a new O ring. ;-)

In article ,
Bob Minchin wrote:
Dave Plowman (News) wrote:
Seems it's a manometer. Presumably to work the gauge which shows the
water pressure?

Possibly but as it goes to the PCB, it will measure the system pressure
and shut down the boiler if it falls below a prescribed limit.

If the pressure gauge is electronic, the same sensor might be used for
the display but otherwise a simple selef contained mechanical pressure
gauge is probably used for the display.

The term manometer is more associated with measuring gas pressures which
is not likely to be monitored by your boiler but also could be measuring
fan air pressure which will be monitored by the control system.

The new part arrived today and it's simply a 'mechanical' gauge connected
by a copper tube to the sensor. No electrical connection. Had it not been
winter, I'd have removed it first - and then tried a new O ring.

--
*Why is the word abbreviation so long?

Dave Plowman London SW
To e-mail, change noise into sound.