28Cdi

[PEDANTICVINDICTIVEMAN]

Got a 28Cdi being strange, 3 connection fan model, casing front off it wont fire even if you bridge APS, fan runs ignition sparks but then goes to fault, put cover on it fires up, take cover off it stays firing, switch off, switch on and fan comes on ignition sparks but no flames, goes to fault, seems to work ok with the front on but not quite 100% somehow, other 28cdi's I go to they fire up without cover on.

 

[DeltaT]

Venturi??

 

[PEDANTICVINDICTIVEMAN]

Blew through both pipes into the fan, both clear

 

[picasso]

polarity and high / low gas pressures ok ?

 

[Bahco]

Nice to see you posting again PVman,

 

[PEDANTICVINDICTIVEMAN]

I marked the fan terninals before disconnection so the polarities should be correct to the fan.
I thought the sequence was fan on APS proved then ignition then gas, I cant understand why when the fan comes on and APS swithes and ignition it doesnt give gas unless the casing front is on, I dont undestand how the gas valve knows if the front is on or off

 

[picasso]

the only thing I can think of is if the gas pressure is very low for ignition, having the case off will give even more air to the mixture, bit of a stretch but cant think of any thing else at the moment.

 

[PEDANTICVINDICTIVEMAN]

Thanks, it is a strange one, I,m going back on friday to put some cleanser in as the system is a bit mucky, not that I am expecting it to sort out the
firing qaundry.

 

[Andygasman2010]

When you say it goes to fault, do you mean fan/flue fault, or ignition failed?

 

[PEDANTICVINDICTIVEMAN]

Boiler stops and lights flash fast on the front panel

 

[Andygasman2010]

Which lights flash fast?? both lights? Have a look on the back of the case for a rough guide. If it's the hot water light flashing fast it mean air flow fault, if it's the central heating light it means sensor fault, if it's both lights that means it's in combustion annalysis mode. Best confirm which you have first. If it's an air flow fault all that means it the pcb hasn't seen the aps close within a given time after powering the fan on. Or.... the pcb checks the aps is open circuit before putting the fan on so if it's not, it'll log a fault. Personally, i've change loads of these aps's for the fault you describe, it's probably that.

If it were to do with gas pressure/ignition etc... you'd be getting the central heating light flashing slowly as your fault.

 

[PEDANTICVINDICTIVEMAN]

Thanks for the info

 

[DeltaT]

We have a customer with the same Worcester Tupperware Bosch appliance, can anyone please tell me where we can get the wee grey button for the filling loop, they have the 'T' bridge piece, but not the grey button to top the system up with.
Cheers
Tricky.

 

[Gasinayr]

Caroline at Heat Spares, Govan.
Part numbre 8.716.121.109.0