Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on
from cold, and it goes through a moment of self test before reporting
fault code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of
the main HE. Basically just to check they were seated properly (to be
fair they did not feel loose the touch). Then I turned it on again, and
this time it all sprang into life normally. So probably just a lose
connection or even a bit of condensation in a connector (the boiler had
been relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
o.uk...
Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on from
cold, and it goes through a moment of self test before reporting fault
code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of the
main HE. Basically just to check they were seated properly (to be fair
they did not feel loose the touch). Then I turned it on again, and this
time it all sprang into life normally. So probably just a lose connection
or even a bit of condensation in a connector (the boiler had been
relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.

That's all very well, John, but what has it to do with Nige?
Oh, heated arguments

On 29/06/2016 03:11, bm wrote:
"John Rumm" wrote in message
o.uk...
Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on from
cold, and it goes through a moment of self test before reporting fault
code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of the
main HE. Basically just to check they were seated properly (to be fair
they did not feel loose the touch). Then I turned it on again, and this
time it all sprang into life normally. So probably just a lose connection
or even a bit of condensation in a connector (the boiler had been
relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.

That's all very well, John, but what has it to do with Nige?
Oh, heated arguments

Lot of gas and hot air, getting into hot water ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

One other issue is corrosion of the pins or socket and moving in and out can
fix the issue.
The low current through these sensors does not keep them clean.
This is not just on boilers seen it in all sorts of equipment with
connectors unfortunately. I doubt if they are gold plated are they!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"John Rumm" wrote in message
o.uk...
Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on from
cold, and it goes through a moment of self test before reporting fault
code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of the
main HE. Basically just to check they were seated properly (to be fair
they did not feel loose the touch). Then I turned it on again, and this
time it all sprang into life normally. So probably just a lose connection
or even a bit of condensation in a connector (the boiler had been
relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 29 Jun 2016 03:06:13 +0100, John Rumm
wrote:

Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on
from cold, and it goes through a moment of self test before reporting
fault code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of
the main HE. Basically just to check they were seated properly (to be
fair they did not feel loose the touch). Then I turned it on again, and
this time it all sprang into life normally. So probably just a lose
connection or even a bit of condensation in a connector (the boiler had
been relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.


Assuming the sensor had a negative temperature coefficient, isn't that
what you would expect from an open circuit sensor?


--

Graham.

%Profound_observation%

On 29/06/2016 12:18, Graham. wrote:
On Wed, 29 Jun 2016 03:06:13 +0100, John Rumm
wrote:

Just in case anyone is getting the same error:

Odd one on a friends boiler (Vaillant Ecotec 824+ combi). Turn it on
from cold, and it goes through a moment of self test before reporting
fault code 76 "main heat exchanger over temperature". Which is quite an
achievement for a cold boiler that has not even lit the burner yet ;-)

So I popped the cover off, had a fiddle with the connectors on the
temperature sensors on the pipes connecting to the input and output of
the main HE. Basically just to check they were seated properly (to be
fair they did not feel loose the touch). Then I turned it on again, and
this time it all sprang into life normally. So probably just a lose
connection or even a bit of condensation in a connector (the boiler had
been relatively unused for a couple of months).

So I figured we could count that as a false positive, so went into the
installer mode[1] menu and erased the fault code history.

[1] The default installer code is 17 for many Vaillant boilers.


Assuming the sensor had a negative temperature coefficient, isn't that
what you would expect from an open circuit sensor?

Yup pretty much - pretty sure its just an NTC thermister.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/