Combi Egg Smell - Help

[edbp]

I have a two year old combi boiler and I’m convinced it is the source of pungent eggy smell.

The boiler is located in our downstairs toilet behind a false wall, with a hatch/door for access. It’s mounted on an outside wall.

The room directly above quite often smells of a drains / eggy smell.

I’m confident the smell is not from the toilet waste and if I stick my head in the top of the cupboard next to the boiler I can smell it.

Any ideas ?

Could there be a leak on the flue / outlet pipe ?

Is it dangerous ? We have a carbon monoxide alarm and is doesn’t go off.


The smell has been there on & off quite some months, during which time the boiler has been serviced by a Gassafe/Corgi engineer. Should he have spotted it ?

 

[corgiman]

what is the make and amodel of the boiler?

 

[edbp]

what is the make and amodel of the boiler?

It's a Remeha Avanta Plus 28c.

 

[barkie1]

just as guess he may have cleaned the condensate trap and not refilled it? or when you flush the toilet it is pulling the water seal out the condensate trap.

assuming the condensate pipe is plumbed into the stack and is air sealed via a bung or boss connection? if this isn't sealed you could be getting the foul smell from open connection. nice!!

But without a few pics or a drawing of pipe runs it hard to say. pure guess work above so don't take it as gospel but it will give you some points to check.

 

[Agile]

Combi boilers dont usually make any significant smell.

It worries me that the boiler might be overheating. Did the installer see it as it is now or was the cover added later?

Tony

 

[edbp]

Combi boilers dont usually make any significant smell.

It worries me that the boiler might be overheating. Did the installer see it as it is now or was the cover added later?

Tony

He's seen it as it is now, the cover/wall was added whilst he was still on site.

Do you think it may be lack of ventilation ?
With the hatch/door closed it's quite a confined space.

 

[edbp]

just as guess he may have cleaned the condensate trap and not refilled it? or when you flush the toilet it is pulling the water seal out the condensate trap.

assuming the condensate pipe is plumbed into the stack and is air sealed via a bung or boss connection? if this isn't sealed you could be getting the foul smell from open connection. nice!!

But without a few pics or a drawing of pipe runs it hard to say. pure guess work above so don't take it as gospel but it will give you some points to check.

I think i've sussed it.
The flexible boiler drip pipe (0.5" diameter) inserts into a black waste pipe (1.5" diameter), thus it's open / loose, there's no seal.
This waste pipe then goes down straight (ie. no U bend) and connects directly into the soil waste pipe from the back of the toilet, this connection is sealed.
Therefore gases are coming straight up the waste pipe and out of the opening. Some may even be going up into the boiler itself and causing god knows what.

So we have an open soil pipe inside the house. Fantastic !!

Is this legal ?

Presumably fitting a U bend will solve this ?

 

[barkie1]

Yes or you could try fitting a washing machine trap to the 1.5'' pipe and then place the condensate pipe inside the up spout. Leaving a minimum air gap of 150mm. So the condensate is not touching the water seal of the trap

Or

you could also get 1.5'' adapter to 21.5mm condensate pipe and fit this into a stright socket fitting (push fit) or into the pipe ((solvent weld) this will depend on material of plastic used for the 1.5'' waste pipe)