Vokera Syntesi35 error 07 continued

[duncanc]

Hi Ray,
thanks for your info, checked out hot water only, would seem to be ok, boiler cuts out as soon as tap is turned off.
Think the sensors could be at fault, as soon as hot tap is turned off the temp immediately jumps up at least 20'C, some times it keeps going up and up fluctuating up to as much as 95'C then back down again the it will settle around 45>55'C. 9If it doesn't shut down on error 07)
Last night I thought heating was ok, now not so sure, would the primary sensor(s) affect the CH though?
When the heating is on should the temp gauge read the heating water temp?
I did find a vokera site telling me error code 07 could be the primary thermister or the wiring.
have ordered new thermisters and the high limit thermostat.
Tonight after 10 minutes found the hot water in the shower went cold twice but came back hot.
Did bleed CH, topped up accumulator to 1 bar(it was low), checked and cleaned the venturi oriffces, they were clear
Any other things to try?

Thanks again in advance

 

[Agile]

Surely the venturiis inside the combustion chamber which only the gas registered should be opening?

It seems that you are continuing some previous discussion.

Obviously this should have been added to the existing rather that creating confusion

Tony

 

[Ray84]

overheat stat will be fine, its more than likely to be the primary thermistor but as tony said because its located iin the combustion chamber and the cover needs to be removed it should be an RGI for the job where as the other thermistor isnt as its not in the combustion chamber.
thermistors when they are out of range playing up can cause all the mentioned problems, even if it didnt cure it probably not a waste of time replacing it

Ray

 

[duncanc]

Thanks again Ray for your advice,
Changed out both thermistor/sensors, boiler working like new again.

Point Tony raised about only an AGI registered plumber should be working on this problem, I respect his concerns, As I work on various pressure vessels, air receivers and Hydraulic systems with S.W.P of up to 7500 PSI
I understand the need to be careful when working with gas, pressures, vacuum systems etc, as this cover is only held on with two spring clips and the side cover with two screws, I do not see this a a high risk repair problem, the boiler has been in service about two years, the gaskets/seals are in good shape, not hardened or cracked with heat/age, also installed at the boiler I have a gas alarm should any gasses escape.
Again thanks for your input and advice.
Much appreciated
Duncan