Vokera Linea Max burner repeatedly starting and stopping

[VokeraSufferer]

I have a Vokera Linea Max (6 to 12 years old?). The boiler has recently started this fault. The boiler jets fire but go out within about 3/4 seconds. It does this continuously once it has got up to temperature. Reading the manual it appears to do this once the 120mA modulation phase is entered.

This is the same on DHW and CH.
There are no error codes displayed.
The Fan, flue pressure switch, 3 way valve and pump all test ok.

I have today fitted a new safety thermostat and Primary thermister with no change.

I intend to fit the recover thermister into the DHW flow pipe tomorrow "just in case" it is that one.

Using a multimeter the modulation voltage at the coil stays around 30Vac.

I am starting to think it is the ignition control board or the main electronic board. Is there any tests I can do to eliminate these two etc.

Any advice would be greatly appreciated as we are living in the kitchen with an electric radiator.

Thanks
Ian

 

[craig51]

Check the air pressure switch, and also the venturi in the fan!!! and ensure tubes are connected to it.

You will probally need to remove the fan to get the venturi out!

 

[VokeraSufferer]

Check the air pressure switch, and also the venturi in the fan!!! and ensure tubes are connected to it.

You will probally need to remove the fan to get the venturi out!

many thanks Craig51 for you reply.

Checked the pressure switch and fan work ok. previously checked venturi by blowing in tube (not easily done) However yesterday had an error 3 come up which is the flue fan. I couldn't clear it until this morning. Think it was a dirty contact on the pressure differential microswitch as it cleared when I replugged it in.

Do you think this could be a symptom opf the same fault?

 

[scatmanjohn]

Get an RGI to fit you a new "ignition control PCB" Its the blue box on the gas valve.

Problem over

 

[fanboy]

The venturi needs to removed and boiled in kettled water to properly clean this device. Common problem

 

[VokeraSufferer]

Thanks Scatman. Hit the nail on the head. Fitted a new Ignition Control Box (£112) earlier this evening. problem fixed.

Saved me a few quid as I was going to go for the main board first.

Cheers