Biasi Garda

[wicksyg]

Hi,
I have a Biasi Garda HE Silver Condensing Combi, it is approx 2.5 years old.
In May this year it developed a fault on the firing pcb, whereas it burnt out the Full ignition sequence PCB at the point where the 7 pin connector plugs onto the board. The connector also melted, the pins that where affected worst were the ones feeding the fan supply. I replaced the board after checking the external electrical circuits for continuity and earth, and cleaned up the 7 pin plug. The boiler has worked fine since.
I do have a problem (from approx 12 months old) in the fact that the boiler will trip out if the condensate trap detector is left connected, the trap is clear and there appears to be no signs of tracking across the probe/detector (the boiler works fine with the detector disconnected).
Last night there was that smell of burning pcb/device again.
I am at work right now, so I will have a good look when I get back home.
The smell is definately around one of the two PCB's. Does anyone know of a similar fault or maybe common fault with this type of boiler?

 

[Bambergaspipe]

I think your pump may need downrating. Chrishutt & fellow Morons will help you out with this.

 

[wicksyg]

Why would I want to downrate a pump that was factory fitted in a boiler?

 

[Agile]

Can you check that the condensate connection is connected to the tag at the top front when facing the boiler?

The PCBs themselves are very reliable. Your fault was almost certainly caused by overheating as a result of a loose connector onto the pin resulting in arcing and overheating of the pin causing it to unsolder itself. Thats very unusual on your model but it could happen.

You should have replaced BOTH the pcb AND the fan connector plug otherwise you will be in the same fault condition again ( now perhaps! ).

Tony

 

[wicksyg]

I have now disconnected and stripped all plugs and devices. There are no signs of overheating/burning on either of the PCB's. All plug/connectors are sound and have good connectivity, even the one that I repaired when the ignition PCB burnt out (reluctant to change it as it would have cost £28+vat, and me being tight and all).
The fan, pump and gas valve have been checked for resistance and are all close enough to the specs in the manual (clear of earth too).
I have reconnected everything and everything is working fine, the burning smell seems to have dissipated some what.
I know if I reconnect the condensate probe the problem would initially be clear then gradually come back over a few days until there was a full lockout (normally when the boiler has been sat idle for a while) the probe appears to be connected well.
The problem did raise its head after I changed the way I drained the water.
initially it went into a big mixing bowl (which just filled up and emptied manually) and the end of the drain pipe was almost always submerged.
The drain pipe now goes into a trap and is always clear of blockages.
Still I'll be waiting for the smell to come back, and the first BBQ in the neighbours garden this week will probably make me run back into the bathroom to check on the boiler.

 

[Agile]

I think that you have given me the clue to the condensate problem.

You say its now going into a trap! The boiler already contains a trap which is 65mm. Building regulations say a trap should be 75mm. So to fully comply you do need a 75mm trap.

HOWEVER when you add a second trap you MUST have an air relief hole in between otherwise thesecond trap "pulls" on the first.

Just add a small hole of perhaps 5 mm to allow the two traps to be balanced.

If the traps have been drained they should be filled before the boiler is used on the earlier types like yours. Later ones have a ball which acts as a seal so they dont have to be filled although its good practice to do so.

Tony

 

[wicksyg]

The condensate trap on my boiler has a ball fitted and the drain/flexy pipe from this trap is open to atmosphere, ie it just sits into the drain trap. Obviously when it was draining away originally the end of the drain/flex pipe was always submerged (into the bowl).

 

[Agile]

Could the ball be sticking?

Sometimes they seem to get some sticky oily stuff on them. If they were to stick then the water would rise too high and touch the contact.

The problem is obviously connected with the condensate trap!

Tony

 

[wicksyg]

The ball is always free to move and everytime the boiler has tripped the water level in the condensate trap was ok.

 

[Agile]

Condensation from moist vapour coming up the drain pipe?

I assume that you dont have a tun dish in between!

If not how about fitting one?

Tony