Getting somewhere with boiler smell!

[Restoration man]

Boiler went off at 10pm as usual and instead of going to check to see if the smell was there 15 mins after I went immediately.

I've sniffed with my nose round the joint between the casing front and the main casing and the smell is coming from the top right hand corner of the casing. It's a horrible acrid smell that makes me cough. It's in the corner only. I've done it a few times its horrible.

So the casing seal must not be right.

So do I just need the casing seal replaced? Why is this smell in the boiler in the first place? Isn't the fan supposed to clear the casing?

Please no usual haters!

 

[ollski]

Forget the case seal, it will have nothing to do with a smell. If it occurs after shut down the likelihood is that the gas valve is faulty and you are smelling a poor combustion smell back through the air intake when the fan stops. Does the boiler show a code when you smell this or does it try to refire quite quickly after it shuts down?

 

[Restoration man]

Never any fault code shown and never tries to refire. The boiler has gone off for the night when this happens.

Could this be an intermittent fault?

Is the air intake the external flu pipe? How can this come into the room?

Does the casing seal not stop anything coming into the room?

Thankyou ollski

 

[Agile]

When the boiler is working you could hold a lighted candle close to a vertical case seal and see if the flame is deflected towards the casing.

 

[HERTS P&D]

When the boiler is working you could hold a lighted candle close to a vertical case seal and see if the flame is deflected towards the casing.

Quote of the year, go around the boiler with a lighted candle?

Andy

 

[dilalio]

Why don't you just adjust the "on/off" times on your boiler to try and get this to occur during a more socialable hour of the day and then call the engineer back and set to it to occur at the time he visits? Then you can demonstrate to another individual, exactly what it is you believe is a fault!

 

[dilalio]

Alternatively, can you upload a sample of the smell?

 

[Restoration man]

Can you answer one question sensibly please.

When the boiler is OFF is the air inside stagnant or Is there a draught flowing through the external part of the flu and then out the inner part always flushing the boiler.

Or are you relying soley on the fan to do this job?

 

[Agile]

When the FAN is off then there is no flow of air inside the boiler.

What did you imagine could cause any air flow?

And why would you like a flow of air?

Tony

 

[shambolic]

There is a5/6 minute fan and pump overrun to cool boiler and clear products after every time the stat is satisfied or boiler switched off at demand.
Does it with HW throughout the day and when heating goes on and off when cycling too so should smell all the time.
Could be overheating PCB or something like that.

 

[Newboy]

When the boiler is working you could hold a lighted candle close to a vertical case seal and see if the flame is deflected towards the casing.

And when you've done that, lick your finger and touch any exposed metal parts to check for electrical faults?

 

[Restoration man]

Agile I just wondered if because there is a venturi and a flu open to outside if there would be a gentle movement of air or not.

It's frustrating it doesn't happen when it's on. Could this be because there is a good flow of exhaust and everything is getting sucked out.

Thanks shambolic. Service eng has never had the control cover off so ill get pcb checked next time.

 

[Agile]

It is a balanced flue with the intake and exhaust in the same place.

So regardless of the ambient wind there should be no air current through the boiler.

Tony

 

[Restoration man]

Thanks Tony.

If the gas valve was passing slightly into the housing while the boiler was off the pressure in the housing would increase slightly. Would this gas be free to find its way out the flu or would it be trapped in the boiler housing?

 

[Newboy]

The gas would vent from the combustion chamber (not the boiler housing) via the flue