Flue Question

[AndrewSwansea]

Should you be seeing much in the way of condensation/steam coming out from the roof flue of condensing combi boilers (Ecotec Pro 28 Vaillant)

Whenever the boiler is on and I am out walking the dog etc I never see much billowing out from the vent. I think this is right as its condensing too there isnt much in the way of waste??

Just that my dads boiler when firing up has no end of steam etc leaving his wall mounted vent - but I dont think his is a condensing boiler.

Sounds a trivial question but after the other errors my engineer made this has made me think slightly.......although I guess we would probably be dead now from carbon monoxide problems if the flue wasnt working properly.

 

[chrishutt]

The amount of visible water (mist perhaps, not steam) in the flue gases will vary with the performance of the boiler and weather conditions. Cold outside air will result in more condensation of water vapour into water droplets.

If you have doubts about the quality of the installation, ask yourself these questions - Was the installer Corgi registered? Did the installer complete the Benchmark record (in back of boiler manual)? Did the installer notify Corgi of the installation (notification number, subsequent certificate from Corgi)? Was the system thoroughly flushed and cleaned?

What other reasons do you have for suspecting that the installation was less than satisfactory?

 

[AndrewSwansea]

Hi Chris

Thanks for response, my difficulties with installer were noted on an earlier thread. Yes he was Corgi reg, I did get a certificate from Corgi but he didnt fill in the benchmark form (which I was unaware of at time)

His general workmanship wasnt great in terms of valves constantly leaking and him having to return etc. I have since signed up with a central heating policy and SWALEC did come out and test and do an initial test for their own records.

Its probably fine as it is roof vented rather than wall so disperses slower

 

[chrishutt]

he was Corgi reg, I did get a certificate from Corgi but he didnt fill in the benchmark form (which I was unaware of at time)

You could call in Corgi. They should be concerned about the lack of a Benchmark record since that is part of the proper procedure that Corgi have told you and your local Building Control has been carried out. At least you would get a completed Benchmark certificate out of it and the Corgi inspector might identify other shortcomings.

 

[bengasman]

If benchmark is not filled out, I would doubt the system a has been tuned and tested. Condensing boiler should always have visible `steam`in cold weather.
If the system is not tuned, boiler set on max and the differential temp is 5K (bit extreme but well possible) the return temp would be around 70-75 in which case condensation is negligible and you will see nothing coming out of the flue.
Call corgi’s illegal gaswork number and tell them that you are advised by a plumber that there are safety concerns but that it is too technical for you to understand. They should sort it out for you.