Ariston A/23 MFFI EuroCombi

[reedybopper]

Hi all,

I own the above boiler and for some time now have been experiencing some problems with it (few years now) but we have just put up with it.

I have replaced the expansion vessel 1 year ago as it was leaking and not holding any pressure. I have also replaced the 3bar saftey blow off valve as this had a small leak, again over a year ago now. All of the above seem to work fine now.

Right, where to begin? SOMETIMES - NOT ALL THE TIME. The rads become that hot that you can not touch them, and eventually the boiler will shut down as a result. I normally just reset this when it cools down and all is fine for a bit. Sometimes I take the electrical connections off the overheat thermostat and the heating sensor, this also seems to help the boiler gain some control back for a while! Sometimes, and this is happening more often now. When you are in the shower, the water will go off! Thus resulting in having to run downstairs to reset the boiler and the back upstairs to try and finish your shower (most annoying). Now it has started to go cold again during a shower, and when you run downstairs to reset it-it has not overheated at all??????? So you go back and turn the shower on, and you get hot water again for a short while????

This is now driving us all crackers in our house now, and the wife is going mad with me telling me I should call british gas to come and sort it.

Could this just be a pcb? If so, I seen them advertised somewhere for £85. It looks a fairly straight forward job to replace (famous last words). Or could this be something more sinister?????

Your thoughts please. This is my first post, so any advice would be greatly appreciated.

Many thanks

 

[bengasman]

could be the pcb, could also be a dozen other things.
start by lowering the radiator temperature on the boiler for a day and see what happens then.

 

[reedybopper]

could be the pcb, could also be a dozen other things.
start by lowering the radiator temperature on the boiler for a day and see what happens then.

Thanks Bengasman, but I am already running the rad temperature on the lowest setting, and for some of the time this seems to be ok. Then, like this morning, the rads were red hot. You could not touch them. I went in the shower anyway, and the shower worked fine until the very end when I had finished then it decided to go cold? I did not check to see if the boiler had turned itself off I forgot, then I went off to work! Even now as I speak the rads are very very hot, but not as hot as they sometimes can get!

 

[reedybopper]

could be the pcb, could also be a dozen other things.
start by lowering the radiator temperature on the boiler for a day and see what happens then.

Thanks Bengasman, but I am already running the rad temperature on the lowest setting, and for some of the time this seems to be ok. Then, like this morning, the rads were red hot. You could not touch them. I went in the shower anyway, and the shower worked fine until the very end when I had finished then it decided to go cold? I did not check to see if the boiler had turned itself off I forgot, then I went off to work! Even now as I speak the rads are very very hot, but not as hot as they sometimes can get!

Sorry forgot to mention in case it makes a difference. I have a mixer shower that just works from the combi. I suppose this is obvious but you never know eh!

 

[bengasman]

thermistors faulty or wonky connection would be my first guess

 

[reedybopper]

thermistors faulty or wonky connection would be my first guess

Hi,
Forgive my ignorance, but what is "Thermistors" and where are they, and what would be the wonky connection?

 

[reedybopper]

thermistors faulty or wonky connection would be my first guess

Hi,
Forgive my ignorance, but what is "Thermistors" and where are they, and what would be the wonky connection?

I would also like to add another thing which I forgot to mention. I have the timer set every day for the same time for Heating to come on. However, when it is playing up, the timer is just ignored by the boiler and will just come on and off when it pleases. Hope this information is of some use to you.

Many thanks in advance.

 

[twgas]

listen to your wife, get someone who knows what they are doing, whether it be BG, another company or an independant.
you seem to have played with safety bits and god only knows if you've refitted them correctly.

 

[bengasman]

thermistors faulty or wonky connection would be my first guess

Hi,
Forgive my ignorance, but what is "Thermistors" and where are they, and what would be the wonky connection?

thermistor = temp sensor

so duff sensor or wonky sensor connection.

not being funny, i think this job is out of your comfort zone.
that means it is not safe for you to continue

 

[reedybopper]

thermistors faulty or wonky connection would be my first guess

Hi,
Forgive my ignorance, but what is "Thermistors" and where are they, and what would be the wonky connection?

thermistor = temp sensor

so duff sensor or wonky sensor connection.

not being funny, i think this job is out of your comfort zone.
that means it is not safe for you to continue

I guess that's that then?

Many thanks.