Greenstar heatslave no DHW

[Mike2007]

Initially the DHW on this oil combi depleted after 10 mins. Now it seems there isn't any hot water but some central heating.
Does anyone with experience of this boiler know what's it's likely to have failed on? Boiler is about 10 years old.
No record of any DHW parts being changed previously.

 

[oilhead]

What burner is fitted, if Riello, then it may not be burning whilst you think it is running. This is caused by a faulty photo cell, but if the burner is firing all the time, then you need to follow the fault finding chart.

 

[Mike2007]

What burner is fitted, if Riello, then it may not be burning whilst you think it is running. This is caused by a faulty photo cell, but if the burner is firing all the time, then you need to follow the fault finding chart.

I find the flow chart for this model limited and inadequate.

 

[Mike2007]

Riello 2.2 I think

 

[Terrywookfit]

Does flow switch activate burner.
Does burner fire on heating demand.
What is combustion readings.
Is pump healthy.