Vokera linea 28 CH and hot water problems

[buckers]

Hi, My previously faultless Vokea Linea 28 has developed a problem.
The CH first heats up to around 55deg. then flames for about 5 seconds then goes out for 10 secs and relights for 5 second cycles etc. No hot water is achieved. However, if the CH is off and the boiler is cold, hot water is acheived.
Any ideas?

 

[gasandoilman]

sounds like the micro swich check that it's making contact?

 

[buckers]

Thank you,
Ive had a look at the micro switch and it appears to be ok. What do you suggest next?

 

[gas4you]

Are you getting a fault code on the display? Try the ch thermistor.

 

[Tinitus]

I have come across this fault a few times it will probably be the ignition board . This is the board fixed to the gas valve.

regards paul

 

[nickso]

I have come across this fault a few times it will probably be the ignition board . This is the board fixed to the gas valve.

regards paul

careful. that usually means it wont get anywhere near 55 degrees in my experience. if it is the board take it out and see if the resistors need resoldering before you go and buy a new one.

 

[buckers]

Hi,
There is no fault code showing, which makes this all the more awkward...

 

[nickso]

Hi,
There is no fault code showing, which makes this all the more awkward...

by pure coincidence i had this very fault today, exactly the way you describe it. the temp you see on the front when in dhw is the dhw temp i believe. the primary temp is actually at 80 degrees when the boiler is showing 55degrees and cutting out.

its not the thermistors or the gas valve pcb.

seems the dhw heat exchanger is not transferring the heat very well. ill let you know tomorrow when i strip it down.