Vaillant Combination Boiler not responding

[RobinsonP]

I have a Vaillant Combination boiler model PLUS824E. At the moment there is no hot water or central heating. The boiler display shows 25 degrees and the green light flashes constantly. When I switch the central heating on the boiler does not respond, when the tap is turned on the boiler starts but the temperature doesn't rise on the boiler display.

This appears to be an intermittent fault as it happened a few weeks ago and by the time the plumber arrived it was working again. He advised that until he sees it not working he is unsure of what is causing the problem and doesn't want to replace expensive parts hoping that it might fix the problem. Has anybody experienced something similar with this model of Vaillant Boiler.

Paul

 

[Agile]

Get the manual and press the "i" buttor and see which fault code it shows and what the book says it is.

Thats only what the boiler "thinks" is the problem!

Tony Glazier

 

[corgigazza]

Green light flashing is the warm start for the dhw this can be turned of using the control diagnostics. May have faulty thermistor or pcb.

The warm start will stop the ch as warm start takes priority until it is satisfied.

 

[ChrisR]

The warm start will stop the ch as warm start takes priority until it is satisfied.

Didn't know that!

It should toggle off/on by turning the HW temp to max.

 

[onion_soup]

It could be aps ? Had similar problem aps and diverter valve was replaced.

Was told apparently aps were to be replaced during service from black
colour to white ( or white to black ). Can someone confirm this ?

 

[ChrisR]

"aps were to be replaced during service from black
colour to white"

Yes, Black ones unreliable apparently

 

[onion_soup]

"aps were to be replaced during service from black
colour to white"

Yes, Black ones unreliable apparently

thanks ChrisR