Water in outer flue combi boiler

[james_m2015]

Hi,

I have a Glow-Worm Flexicom 30 cx installed in a ground floor flat. A couple of weeks ago it started reading error messages F4 and F13. The Glow-Worm man who came round opened it up to find some water inside the boiler and said that we had to call the installation man as it looked like an issue with the outer flue. The engineer who installed it came round and remeasured everything and confirmed it was as the installation documents required, he confirmed it was safe to use. He reset a number of things (not too sure) and adjusted some settings. This seemed to work for a bit however it has since gone back to cutting out and F4/F13 error messages.
I have opened up the boiler and looking through the back there is water collecting in the outer flue, which I understand is not supposed to happen, this water is then slowly dripping down the internal workings of the boiler and causing sensor errors.
I had thought that it could be issues with overflow pipes above, however the error messages only occur after the boiler has been on for 5/10mins, suggesting it's an issue with the boiler.
Are there any reasons why an outer flue would be slowly collecting water when the boiler is in use?

thanks,
James

 

[simond]

Yep, there's something wrong with the flue (eg: it has a hole in it) and saturated vapours are being drawn into the air inlet, assuming the boiler is not losing pressure.

This is potentially dangerous and will also quickly corrode the boiler to bits, leaving you to buy another one.

The first thing the technician (either of them) should have done is measure the air inlet for presence of Co2.

 

[Agile]

We don't know anything about your installation. It can be caused by a fault with the flue or an external fault like an overflowing gutter.

You don't say when it was installed either. That identifies whose responsible for solving the problem and who pays.

But we cannot give engineering advice here on gas/combustion related matters.

Neither of the engineers you have had seem to have been able/willing to actually identify the real cause of the problem.

 

[Lower]

I had something similar with a Glow worm Ultracom flue. Water was collecting in the outer flue and then running back and leaking out of the boiler casing. It didn't cause a fault with the boiler, just rusty water marks on the carpet under the boiler and some actual rust on the top of the boiler outer casing.

The fault was that the adjustable flue pipe hadn't been assembled correctly. When the installer had cut the inner flue he hadn't bothered to deburr it. The inner flue seal ring was damaged and allowed it to leak very slightly.

It was eventually identified by me shining a light down the outer flue from outside when the boiler was running and condensing and you could see a very occasional drip. A number of gas engineers came to look at it unsuccessfully before the cause was found.

A deburred inner flue and new seal ring would have fixed it but it had been going on for a number of years and the outer flue was well rusted so i ended up having the whole flue replaced. Thankfully a fairly easy, quick and inexpensive job.

 

[james_m2015]

the flue is a direct rear flue, installed 2 years ago. It is covered by my landlord's boiler insurance (however the landlord was not covered for the installation technician call out).
The technicians suggested that it is not to do with external faults like overflowing gutter because when the boiler is not in use there is no water, ie water only gathers when the boiler is used. If it were an external fault then water would be entering in the whole time.

 

[Agile]

So it is a landlord's boiler.

If it is an installation fault which now seems very likely then it is still the responsibility of the installer. Getting him to correct his bad workmanship after two years is likely to be almost impossible with those who do installations for landlords who usually want the cheapest installers.

The boiler breakdown scheme will probably not cover pre-existing installation faults but that depends how helpful the individuals are feeling at the time.

Tony