Worcester 28CDI

[Shivverinn!]

We had one of these boilers fitted 18 months ago, it's a combi and during the summer it's ok, but during the winter it dosent work too well.
In the summer we just have the hot water on demand, but obviously in winter we have both and this is where the problem is.
Every time hot water has been used the boiler goes out and the heating goes off, this has been like this since it was new.
About 9 months ago (last may i think) the service chappis came and put in a new heat exchanger because it went out and wouldnt re light ( i want here - i was away fishing at the time...) anyhoo, it's exactly the same and even when the hot water tap isnt used it still goes out, sometimes five or more times everyday.
It's a council house and we've had them out to it a few times ut they say it's not their problem or 'it's working now' etc etc.
Obviously it's not right, and it never has been, what i want to know is, is this a recurrin problem with this type of boiler?
Is there some setting i can fiddle with?
or is it just a duffer?

 

[COG]

First off are you sure it was one of the heat exchangers they replaced as that would not stop the boiler from re- lighting. Second what do you mean when you say "go out" the cdi should flash one or more of the panel lights fast or slow to indicate what the fault may be, you would re set by switching off/on for a fast flash and pressing the red button to re set a slow flash, ?.
If you are sure you have the same fault as last time then contact worcester and explain in detail for a free visit

 

[Shivverinn!]

First off are you sure it was one of the heat exchangers they replaced as that would not stop the boiler from re- lighting. Second what do you mean when you say "go out" the cdi should flash one or more of the panel lights fast or slow to indicate what the fault may be, you would re set by switching off/on for a fast flash and pressing the red button to re set a slow flash, ?.
If you are sure you have the same fault as last time then contact worcester and explain in detail for a free visit

Yep it was the heat exchanger they replaced, but that time it just packed up altogether,with it being summer, it was just set up for HW and the CH was off, whether the recurring problem is connected I don't know.
The light which is always flashing slowly is the ignition failure light, when reset, it fires up and does it's thing, but at least 5 or more times in every twenty four hours it goes out and has to be reset this way with a quick (2 second) push of the red button.
As I said earlier, nearly everytime after the HW has been used and a few other times every day..

 

[COG]

I trust you mean its the CH light that flashes slowly which indicates flame failure. In my experience the gas valve tends only to be a problem on cold starts not ie first thing in the morning, and the flame sensor tends to fail fully or very intermittent BUT a not to uncommon problem is flame lift off particularly with a vertical flue.Your boiler is on max gas when in hot water mode and if the flue outlet is damaged on installation it will have trouble clearing products and drawing in air resulting in the flame lifting off the burner and away from the flame sensor,run the bath tap on full and observe the flame closely thru the window