Vokera Linea 28 Hot Water Issues

[davewatt]

Hi All,

I've just moved into my house and the combi boiler is playing up with DHW. You turn on the tap, it heats up until it is too hot to keep your hand under then the boiler cuts out and relights again in a few seconds (this makes having a shower very difficult!). This happens even with the hot water temp dial set to the lowest setting.

I've done some investigating and the flame doesnt seem to be modulating, its either full or off, there is a varying voltage from the PCB to the mod coil so I assume the PCB's OK.

My question is what should happen when I unplug the mod coil, should the burner go right down? Currently the boiler operates the same with the mod coil unplugged (gas on full then off then full etc.)

Is this indicating a stuck modulation valve, if so do I really have to replace the whole gas valve unit as intimated in the service manual?

Any help would be appreciated,

Many Thanks,

Dave

 

[Boilerman2]

You will need a Gas Boiler engineer to either set up the existing modureg or if not possible replace it not a DIY job!

 

[Agile]

There could be several different causes but they all need a registered engineer.

 

[bengasman]

Not a good idea to start fiddling with gasvalve connections/settings if you don't know what you are doing.