Ariston Eurocombi a23 problems

[Heywood_87]

Hi,

Just wondering if anyone can help? I have an ariston Eurocombi a23. I seem to have an intermittent problem with the boiler firing up. Generally there is no problem when the CH is being asked for. When HW is being asked for the boiler starts up,(fan starts up) but the igniter doesn't ignite. To get around this problem I have being starting the boiler via the CH and then running the HW. But sometimes after a couple of minutes the pilot light goes out and the water runs cold. Then it's a bit of a faf then to get the boiler to ignite again. Any help would be appreciated. Thanks

 

[Agile]

Sounds like a gas related problem which we don't advise on here.

Tony

 

[hertsboilers]

No, it is a diverter valve problem.

 

[Agile]

As the fan starts up, then what diverter valve fault do you anticipate Ming?

Tony

 

[hertsboilers]

Diaphragm not making DHW flow switch.

 

[hertsboilers]

To be more accurate, diaphragm makes a push, so fan starts for a while, then back to not.

 

[Agile]

But if that were the case why would the fan be started?

Tony

 

[hertsboilers]

Seen a lot of times, the rod on diaphragm moved out once at the beginning on DHW demanding, to triggled the fan, then diaphragm moved backwards.

 

[Agile]

Would that not stop the fan immediately though if the DHW demand switch was deactivated?

But the OP could identify the switch and see if the pin is staying fully extended or not.

Tony

 

[hertsboilers]

Tony, if you read this boiler manual, you will know it hasn't got anything else to stop DHW, there is no NTC for DHW etc.

I don't often reply on customer's discription through.

 

[Heywood_87]

Thanks for your replys I have checked the diverter valve and it is making the microswitch. The issue I now have is that the boiler won't ignite at all for either HW or CH. I have removed the boiler front cover and then removed the cover that allows you to access the air pressure switch and the fan (NOT the combustion chamber cover). I checked the air pressure switch and everything seems fine. I turned the HW on with this cover off and the boiler fired up straight away. I tried the same for the CH and again it fired up straight away. As soon as I put the cover back on, the boiler won't fire up. Has anyone got any ideas at what this could be?

 

[hertsboilers]

Weak fan, defected air pressure switch, blocked flue way, or blocked venturi.

Very likely venturi.

 

[hertsboilers]

Sorry to say you are not allowed to open the second cover. no more advice from me on this issue now.