Vokera 20-80 RS Flowmatic - Gas Pressure - Help!

[Robbie1980]

Any one out there who could give me some advice - would be appreciated.

I heard a rattling with my boiler tonight and took the case off. It was the 10mm locknut which holds the gas pressure. I didn't realise this at the time and in tightening the lock nut with my fingers (and not carefully) I have screwed up the gas pressure.

I have turned the boiler off as not to do any damage.

The badge on the boiler says the burner pressure was set to 7mbar. Is there anyway to set this without a U gauge? It's a small job but one i dont have the expertise for.

I'm guessing the coarse and fine adjusters control the HW aswell as CH.

Anyone in Wakefield/Leeds area tomorrow?
Cheers
Rob

 

[corgiman]

NO!!!

stop and get a decent RGI to sort it out

Pronto

 

[Robbie1980]

Thanks

I did turn it off and seek advice !

RGI = corgi?

You can tell i'm a novice
Rob

 

[Robbie1980]

oh........registered gas installer

 

[Robbie1980]

just another related question...

the installer has written 7mbar gas burner pressure on the boiler but the manual says 9.5mbar +/- 0.95mbar.

Why would there be a variation?
thanks
Rob

 

[gas4you]

If the manual asks for 9.5, then that is what I would set it at

 

[DP]

7 mbars is the heating burner pressure. 9.5 mbars is the hot water burner pressure. One is set on the gas valve, other on the PCB

 

[Robbie1980]

Ah Thanks DP

So as i adjusted the pressure on the gas valve ( as described above) and when i flicked the heating on momentarily the CH burner pressure had increased so the gas valve (CH) must be reset to 7mbar.

As i haven't touched anything else i presume the hot water burner pressure wont have been altered.

Is this right?
Cheers
Rob

 

[DP]

You need to call in a gas engineer to set the gas valve. Not any gas engineer but one who can set the gas valve on the Flowmatic. It is set a little different from other mod coils.

 

[superdupergasman]

And watch he does not break the little brass screw in the middle as the modu reg is no longer available for these boilers!!!!

Keep the instructions handy for the eng!!

 

[Robbie1980]

Thanks for your help so far.

I had a Corgi Engineer come out and set the max and min gas pressures as per the instruction book and all seemed well.

The vibration problem i had before is now back and both the coarse and fine adjustment locknuts are secure.

It is the thin brass screw (long) which is vibrating as when the small locknut is loosened and the brass screw turned in one turn it stops. Maybe at its natural frequency...

I watched the Eng do the work and the brass screw hadn't broken.

Any ideas how to fix this? Is there any gas sealant which can help secure the brass thread or is it worth replacing any parts?

Thanks again,
Rob

 

[DP]

I would consider replacing the PCB.

 

[Robbie1980]

The main PCB? Why would that have an impact?

Oh i presume there is a small PCB which the HW (max and min) flow rates are set on.

Can this be bought individually or do i have to buy it part of a unit?

Thanks DP

 

[DP]

The small pcb is an anticycling delay unit. The vibration from the mod coil almost certain to be raw 12 volts from the PCB. Capacitor comes to mind.

 

[Robbie1980]

Cheers,

Are the PCB's available separately? Any advice where to get them from?

Is this something I can strip and fit myself (when isolated) and get a Gas Eng to come and set the gas pressures again?

Rob