More Vokera 20-80RS flowmatic problems...

[24valve]

Hi All - Back again

Follwing last weeks impressive fix of replacing my low speed fan resistor to cure the RCD tripping fault, this week I are be mostly scratching my head again.

To my surprise, 3 days after fitting the new resistor, the RCD tripped again. When I switched it back on, it occurred to me that the fan wasnt actually running - I figured this after realising the casing was getting pretty hot to touch.

Much deliberating later I found the microswitch on the manifold to not be switching - it would do manually (if I pushed the little lever on the microswitch the fan runs normally), but the pin going to the diagraghm on the manifold was pretty stiff.

I duly ordered a replacement diagraghm and for good measure a new microswitch, replaced this (after cleaning it all up) and then tried it again.

Bingo - everything is working o.k - no tripping of the RCD, and I can switch the heating on no problem....except, the burners dont fire up when I switch on the hot tap.

As a result, I can only get hot water when the CH is running.

If I look at the pins on the diverter valve and manifold, whilst the better half turns the tap on, they seem to go in and out in sync, which would make me think this was o.k.

The only other slight concern I have is that resistor gets damn hot almost as soon as I switch the boiler on - I cant ever recall if that was normal. I have got the old resistor, whcih I plugged back in, and it acts in the same way.

Any ideas where to turn?

Cheers

Neil.

 

[nickso]

Pull the fulcrum arm all the way out manually and make sure it hits the microswitch on the end, burner should fire.

If it does then replace the DHW diaphragm as it may be stretched and not able to make the switch. If it doesn't fire as above then check the microswitch. They have more of a habit of sticking on than off but anything is possible.

 

[Tibbot]

Fulcrum arm on Excell model only. Flowmatic doesn't have one. OP- replacing diaphragm is not enough. Diverter valve needs stripping & servicing as well.

 

[nickso]

Whoops.....thats what I get for not reading the title properly.

 

[Agile]

I still dont see why the RCD was tripping nor why you replaced the resistor.

They do get quite hot. I suppose putting some heat transfer paste underneath will help transfer heat to the casing underneath.

Obviously the diverter valve does not seem to be operating correctly if it does not bring the boiler on with a DHW demand.

You mention the pin but not the switch ???

Tony

 

[DP]

Hint. It is only polite to tip your hat when someone gives you way, or say thank you when some one holds the door open for you

A little thank you would not be out of place. You have regulars taking time out to render assistance

 

[24valve]

Hint. It is only polite to tip your hat when someone gives you way, or say thank you when some one holds the door open for you

A little thank you would not be out of place. You have regulars taking time out to render assistance

Hi

I apologise if it didnt sound like I was grateful - and I must admit I thought I'd expressed my thanks on my previous threads, and if I didnt, I sincerely apologise.

I have so far been indebted to each and every responder on here regarding this boiler, and again I apologise for not saying thanks on this particular issue - I've only just read through everyones responses this morning.

Regarding the current issue - I've looked again this morning, and found that if I remove the microswitch on the manifold, the hw fires the burner just fine, which leads me to think that the divertor valve IS the issue (becuase the pin on the manifold doesnt retract when the pin on the divertor valve pops out).

Thank again for all your help.

Neil.

 

[24valve]

I still dont see why the RCD was tripping nor why you replaced the resistor.

They do get quite hot. I suppose putting some heat transfer paste underneath will help transfer heat to the casing underneath.

Obviously the diverter valve does not seem to be operating correctly if it does not bring the boiler on with a DHW demand.

You mention the pin but not the switch ???

Tony

Hi Tony

The Resistor was replaced because the RCD was tripping out - if I removed the Resistor, the RCD didnt trip - and to be fair I figured there must have been something wrong with it, if replacing it didnt cause the RCD to trip for at least 3 days.

It is looking like the Diverter valve now.

TBH, I've got to the stage where I wish I could just get someone in to sort it all, but there isnt anyone in my area who knows the boiler and can work with LPG.

Thanks for all your advise so far.

Neil.