Baxi 80e Combi Boiler Woes
- Thread starter migrantwing
- Start date
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Clearly information is erroneous as someone relying on what you post would automatically assume you are correct and end up changing components that may well be fine. Those values you quote will certainly make boiler work in like never intended and function erroneously too.
Clearly information is erroneous as someone relying on what you post would automatically assume you are correct and end up changing components that may well be fine. Those values you quote will certainly make boiler work in like never intended and function erroneously too.
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I guess you missed this comment I made "" The thermistors used in boiler temperature sensors are almost certainly going to be lower cost devices, most likely with a steeper T/R curve ""
To say the thermistor is good if the measured resistance is anywhere between 1 KΩ and 30 KΩ is not good advice. It implies that any thermistor that was, irrespective of the temperature, between 1 KΩ and 30 KΩ would allow the boiler to accurately sense temperature.
The resistance of the thermistor on one type of Baxi is quoted as 680Ω at 80°C and on a different model it is 1.5KΩ at 80°C .Each type of boiler has it's own type of thermistor.
Two different themistors and both would pass your 1KΩ to 30KΩ at room temperature, one would fail if the temperature wa about 80°C
But put the wrong type into a boiler and then when the water was close to boilng point the PCB would be getting from the thermistor a resistance that suggested the water was about 80°C
So why bother posting information you know is likely to be wrong?
Stay off Google.
Stay off Google.
Bernard I'm not sure what point you're trying to make. The specific sensor we are talking about on the baxi 80e operates from 0.9 - 30kohms between 0 -100 degrees. If the thermistor stays between this range and the boiler faults with the 'dhw thermistor fault' error code the the pcb or harness are faulty, if the resistance falls outside this range then obviously thermistor itself is faulty. I haven't bothered quoting specific resistances and temperatures through the curve as the op almost certainly wont have surface temperature probes but may have a multimeter.
Is that to me or to DP
Google is one of several ways to find manufacturer's documentation about their equipment. Another of my sourced is a mailing list of experienced and qualified engineers covering a wide range of industries.
As to DP's method of testing a thermo couple temperature sensor...... Even Baxi provide a value for their temperature sensor at "cold" in the public domain information they produce.
Primary temperature sensor faulty.
Cold resistance approx. 11K ohms
(resistance reduces with increase in temp.)
Google is one of several ways to find manufacturer's documentation about their equipment. Another of my sourced is a mailing list of experienced and qualified engineers covering a wide range of industries.
As to DP's method of testing a thermo couple temperature sensor...... Even Baxi provide a value for their temperature sensor at "cold" in the public domain information they produce.
Primary temperature sensor faulty.
Cold resistance approx. 11K ohms
(resistance reduces with increase in temp.)
The point I am making, an I am surprised that I have to make it to "qualified engineers" is that the test has to verfy that not only is the themistor present and not open circuit but that it is still within specification ( and not the wrong type ).
As in my last post manufacturers do provide values for the thermistors at "cold" temperatures and this value should be used to verify that the thermistor is within specification at "cold" temperatures. It is still chancing that the thermistor is accurate at higher temperatures.
Yet you put information up about a totally unrelated product.
Take your morning meds before you do something even more senile and hurt yourself.
Take your morning meds before you do something even more senile and hurt yourself.
That's at room temperature (21 degrees), the operating range which the pcb can expect to see is 0.9(100degrees) - 30kohms(0 degrees), if the range stays within that the fault will not be generated by the pcb unless the pcb is faulty. What do other random thermistor readings have to do with anything? (fortunately primary and dhw have the same exact readings and curve on this model)
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Bernard, what has thermocouple got to do with thermistors.
Clearly information you glean from public domain is not making sense to you as not only are you quoting wring value, you are also confused if you think thermocouple can provide resistances you quoted in your post
Clearly information you glean from public domain is not making sense to you as not only are you quoting wring value, you are also confused if you think thermocouple can provide resistances you quoted in your post
He is only a bored old retired person who seems to enjoy posting totally irrelevant information.
Rather annoying for the professionals here who try to give correct and focussed advice!
Perhaps one day the site owner here will realise that its tine to ban him.
Tony
Rather annoying for the professionals here who try to give correct and focussed advice!
Perhaps one day the site owner here will realise that its tine to ban him.
Tony
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Agreed. Copying and pasting from Google can be difficult at times
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