Vaillant Ecotec vertical flue minimum distance from soil pipe

[Paul Mc]

Hi All

Has anyone ever questioned the reasons why Vaillant MIs for their vertical flue termination refer to damp exhaust air escapes from “channel vents” may condense in the air pipe and cause damage to the product, this would suggest that the flue terminal has to be at least 1 meter away on either side from a soil pipe and at least 3 meters above if the soil pipe is below

the attached photo is taken from the MI on page 4

I appreciate the obvious answer is to phone Vaillant Technical, however it being a bank holiday and a flue termination position diagram that I had not seen before I thought it might be useful to ask the forum

Thanks

Paul

 

[Scott_D]

Vent air is contaminated so not ideal for combustion?

 

[Paul Mc]

Hi Scott

That makes sense, however you would guess that would only have a temporary affect on combustion depending on the weather conditions and wind directions, however the MI state it will damage the product, so this makes me think the damp air will damage the air intake flue?

 

[Scott_D]

I don’t know the science but I assume if you draw in lots of methane and mix it with gas it could create an explosive mixture.
It could also be corrosive to the metal outer flue it damage the rubber flue seals.

 

[Paul Mc]

Hi Scott, a boiler flue only needs to be a minimum 300mm away from a cooker extractor vent which is definitely pushing out contaminated air, I agree you will have contaminated air which contains moisture leaving a soil stack and had the MI stated 300mm may not have given it further consideration however the diagram states 1 meter and 3 meter, Ive tried to attach the photo from the MI however it keeps getting blocked

Thanks

Paul

 

[snowhead]

This one,, (won't post as an image, tech issue at the moment I beleive)

I assume they mean air from a Soil and vent pipe or Shower / Bathroom extract condensing in the boiler air inlet tube and the water running into the casing.
This wouldn't happen in a horizonatal flue.(needs minimum 20 characters per post, still)

View attachment Vaillant flue roof.PNG

 

[Paul Mc]

This one,, (won't post as an image, tech isue at the moment I beleive)(needs minimum 20 characters per post, still)

View attachment 43684

This one,, (won't post as an image, tech issue at the moment I beleive)

I assume they mean air from a Soil and vent pipe or Shower / Bathroom extract condensing in the boiler air inlet tube and the water running into the casing.
This wouldn't happen in a horizonatal flue.(needs minimum 20 characters per post, still)

View attachment 43684

Hi

This one,, (won't post as an image, tech issue at the moment I beleive)

I assume they mean air from a Soil and vent pipe or Shower / Bathroom extract condensing in the boiler air inlet tube and the water running into the casing.
This wouldn't happen in a horizonatal flue.(needs minimum 20 characters per post, still)

View attachment 43684

This one,, (won't post as an image, tech issue at the moment I beleive)

I assume they mean air from a Soil and vent pipe or Shower / Bathroom extract condensing in the boiler air inlet tube and the water running into the casing.
This wouldn't happen in a horizonatal flue.(needs minimum 20 characters per post, still)

View attachment 43684

Hi Snowhead

Yes this is the flue termination position diagram that I tried to post, still interesting that Vaillant believe that damp air from a soil pipe or extractor, which I would guess would be warm and rising, could find it way into an adjacent vertical flue if the flue is closer than 1 meter either side or less than 3 meters above, Ive not seen this diagram with any other MIs

Thanks

Paul

 

[Chuck]

Has anyone ever questioned the reasons why Vaillant MIs for their vertical flue termination refer to damp exhaust air escapes from “channel vents” may condense in the air pipe and cause damage to the product,

My guess is that the instructions were originally in German and used the word 'Kanal', which can be translated to English as 'channel' but also means 'sewer' or 'duct', etc. Evidently the translator picked the wrong one for this context.