Hot water smells like eggs - running off a Combi

[lognak]

Hi,

Over the last day we've noticed the HW is smelling likes eggs.
We have a Swift Flow 100 Combi which was serviced a month ago. The engineer cleaned out the fan which was caked in crust. Apart from that, a routine service.
It's been fine since the service and not even sure it's anything to do with that.

One other factor which I doubt would have an impact is we've had a radiator removed and the valve is dripping very slowly, but enough to gradually reduce the system pressure. The pressure was around 0.8 but I've topped the water back up to get the same pressure back (albeit until for a short while).

Does anyone have any ideas what could be causing the HW smell from a Combi?
The cold water doesn't smell.

thanks,

 

[OwainDIYer]

If you bleed a radiator do you get any smell from that?

 

[gigz]

Was it serviced by an ill-eagle

Sorry.

 

[Dan Robinson]

Was it serviced by an ill-eagle

Sorry.

I remember that thread. Haven't laughed so hard on an Internet ever.

 

[lognak]

" you bleed a radiator do you get any smell from that?"

... no, there was no egg smell from the Rad water. It's just the running HW that seems to smell.

 

[HERTS P&D]

Does it smell from all hot taps or just one of them?

Andy

 

[OwainDIYer]

" you bleed a radiator do you get any smell from that?"

... no, there was no egg smell from the Rad water. It's just the running HW that seems to smell.

Unikely to be a heat exchanger / diverter valve leaking between the HW and CH then.

 

[GuessMan]

The swiftflow doesn't have a diverter valve, it is a bithermic heat exchanger.

I cannot remember if the hot water tubes run withi the system water tubes. But if they do this would mean there is a leak between the two. This would be new heat exchanger time, but alas they are now obsolete.

The dropping system pressure is the probable cause, the low water pressure switches get blocked and may have allowed the boiler to dry fire.

New boiler time. But Glowworm are dropping cover for them, so it was only a matter of time anyway.

 

[45yearsagasman]

bithermic heat exchanger.

That's one I haven't heard before, live and learn.

 

[GuessMan]

bithermic heat exchanger.

That's one I haven't heard before, live and learn.

I don't name them, as an ex manufacturer slave, just repeating what they call them.

 

[Bunnyman]

If the the biothermic heatexch had split internally the pressure would rise as the mains bleeds through to the heating it wouldn't decrease would it

 

[ianmcd]

If the the biothermic heatexch had split internally the pressure would rise as the mains bleeds through to the heating it wouldn't decrease would it

My thoughts exactly

 

[ianmcd]

As has been mentioned there is a scenario where bacteria can be present in your radiator water that can smell like rotten eggs but cant see how that could pass into your domestic hot water as it is at a lot lower pressure so the contamination would be the other way unless the pressure releif valve for your boiler is capped off or something ? please come back and let us know what the cause was once you find out

 

[GuessMan]

If the the biothermic heatexch had split internally the pressure would rise as the mains bleeds through to the heating it wouldn't decrease would it

Yeah yeah yes, got me there

 

[Bunnyman]

I don't know 3 weeks away an u gon to pot lol! Was it that bad?