Vaillant ecomax flue corrosion?

[Scott_D]

Can you unscrew the flue collar, slide it out the way and see what’s happening inside?

 

[Last Plumber]

I did that. Then the customer got another engineer out who called Vaillant who said it’s fine. He then told me that the other engineer had switched it back on. I told him good for him. But I wouldn’t be signing to say it was safe. That looks like it is inside though. Mine was outside.

Each to his own I suppose. There are all sorts of unknowns with a flue like that as I'm sure you know. If others disagree and leave it without further investigation, that is their own look out.

 

[Harvest Fields]

Each to his own I suppose. There are all sorts of unknowns with a flue like that as I'm sure you know. If others disagree and leave it without further investigation, that is their own look out.

Looks bad on the first engineer though when it gets turned back on

 

[GrahamM]

Pretty sure it's rainwater, if it was condense then surely the flue would fail integrity test. I wrote a warning notice explaining the flue is ok now but there is a risk that future it isn't, I don't think it's at risk of failure any minute but advised to replace anyway. Customer is weighing up whether it's worth it though as boiler is 15 years old and the temp dial for the heating does nothing too so probably not worth spending money on.

Just be aware!
I have had countless situations where combustion is spot on and air intake testing out 100%, but when delved deeper found pinched inner seals was cause.
Initially thought was just rain water ingress.

 

[Sharp Point]

Just be aware!
I have had countless situations where combustion is spot on and air intake testing out 100%, but when delved deeper found pinched inner seals was cause.
Initially thought was just rain water ingress.

I agree, a dislodged seal leaking condo doesn’t give out of sync fga readings

 

[Scott_D]

Pretty common on vaillant flues isn’t it?

 

[Harvest Fields]

This is why I would AR

 

[Aire]

Good to know for future if its a common fault. Hard to say how long the flue will last but warning notice was issued and customer happy with my explanation so can't do any more than that.

 

[Last Plumber]

Looks bad on the first engineer though when it gets turned back on

It does but the first Engineer was being cautious and correct in putting safety first. If the second Engineer puts it back on after a deeper and more rigorous inspection, he/she takes on the responsibility but knows the cause of the corrosion and must be satisfied there is no risk.
Some will just turn it back on regardless and they are very silly people.
I think the end user can tell if the Engineer is talking sense or not, most of the time.

 

[Millsy 82]

Vaillant flue seals are crap. They warp out of shape and a bit of condense passes through and causes this issue. It doesnt let gases through but condense seeps through.