Ariston Euro Combi hot water problem

[Marky-boy]

I have an Ariston Euro Combi .Its about 4 to 5 years old ,When the hot water tap is turned on the boiler turns off, If the boiler ran on constant we used to get hot water with the tap on a slowish flow rate. The raidiators all seem fine just the hot water problem .The water pressure looks ok .
It had a new pcb fitted 18 months ago due to the boiler constantly trying to ignite the pilot lite , Has any one any usefull recomendations or surgestions

 

[Agile]

If the heating is OFF then what happens if a hot tap is turned ON ???

 

[Marky-boy]

If the heating is on timed and not activated ,or the boiler is switched to supply hot water only the boiler ignors any request for hot water .The tap runs but the boiler dosnt ignite other than the pilot being on .There has been occasions in the past were the raidiators have got hot when the hot tap has been opperated .The last enginer termed this as transfer and said while it was a problem it wasnt terminal . and the price quoted to fix was half the price of a new boiler !

 

[corgiman]

its probably the dhw flow swtich that is sticking, I am sure they do a new type for it now, easy to change

 

[Marky-boy]

Thanks for the advise I will have a look this weekend .