ARISTON EUROCOMBI A/23 MFFI -Water runs cold ?

[technics97]

Greetings,

Can anyone help with this one,

I have an Ariston euro combi A/23 mffi which I'm told is over 10 years old. Its started playing up. The central heating side works fine, radiators heat up - no problem. The problem is when I put the shower on in the morning. The burners ignite immediately and the water appears to gradually heat up and then starts to run almost cold. I checked the burners and they are still lit when this happens. I find turning the tap on and off a few times will eventually cause the water to start running hot.

Can anyone suggest what the problem might be ?

thanks

Rob

 

[mrgas]

Let your boiler go cold.
Run hot water.
Does the heating flow pipe get hot?
Your diverter valve could need attention.