Condensing boiler flue too close to eaves?

[Consumer]

Was intending to get my old Potterton Puma combi boiler replaced with a Worcester Bosch 24i Condensing Combi. My CORGI registered installer is worried about the fact that in my top (3rd) floor flat the terminal will be 520mm below eaves that project by a total of 530mm including the plastic guttering.

He muttered something about taking the flue up the wall, making a hole in the eaves and then a hole in the roof above. This would be a prohibitively expensive operation involving three storeys of scaffolding, quite apart from the extensive roof modifications and it would never get approval from the freeholders.

A plume management kit is not an option either as it has would have to have angles and bends in it to take it out past the eaves and guttering; this would be unsightly and also involve scaffolding to get the pipes supported. The fact is that if I am to have the boiler replaced at all then the terminal has to just poke out of the only available hole in the wall where the old Potterton Puma's flue is.

The terminal can not project in a straight line by the 530mm required to get past the overhang as it would then be an unsupported pipe.

There are no other major proximity issues, as the only window within 600mm from the terminal in any direction is the ventilator grille for the old larder now used as the boiler cupboard and this can be blocked up.

So, finally, here is my question: Is my CORGI man right to be concerned or am I right in saying that siting the terminal 500mm below the eaves should be perfectly ok, no matter how much the eaves overhang?

 

[gas4you]

How about a flue support clip fixed to the eaves. Most manufacturers I know supply them, albeit probably in packs of 3 or 5

 

[giblets]

The Installation Instructions for the 24i Junior state a minimum of 200mm below eaves so I can't quite see what your installer has a problem with. Granted your eaves are quite large but even below a balcony the min distance is still 200mm.

 

[GasMan1965]

Below eaves for that boiler is 200mm minimum so your ok

 

[gremlin16]

As you said MI says 200mm.

Cant see what the problem is?

Unless he's scared of hights

 

[GasMan1965]

Out of curiosity how much is it costing ?

 

[giblets]

He doesn't need to worry about heights - the flue can be fitted from inside the building.

 

[GasMan1965]

Sounds like he wants to make a few ££££ extra

I suggest you have a magnaclean fitted as well !!!

 

[gremlin16]

He doesn't need to worry about heights - the flue can be fitted from inside the building.

How is going to seal the outside then ?
WB flues slope back to the boiler. if you have no seal on exterior any water will eventually track back to interior wall

 

[GasMan1965]

He doesn't need to worry about heights - the flue can be fitted from inside the building.

How is going to seal the outside then ?
WB flues slope back to the boiler. if you have no seal on exterior any water will eventually track back to interior wall

The outer collar self seals

He wont be getting any rain hitting that flue with the size of them eaves

 

[giblets]

He doesn't need to worry about heights - the flue can be fitted from inside the building.

How is going to seal the outside then ?
WB flues slope back to the boiler. if you have no seal on exterior any water will eventually track back to interior wall

I am only quoting what it says in WB's Flue Installation Instructions for that boiler.

With other makes hole through the wall is drilled larger, the external rubber sealing gasket is fitted to the flue, the flue is pushed through the hole until the rubber seal is past the external wall face and the flue is then pulled back.

edit: Cheers GM - far simpler put.

 

[GasMan1965]

He doesn't need to worry about heights - the flue can be fitted from inside the building.

How is going to seal the outside then ?
WB flues slope back to the boiler. if you have no seal on exterior any water will eventually track back to interior wall

I am only quoting what it says in WB's Flue Installation Instructions for that boiler.

With other makes hole through the wall is drilled larger, the external rubber sealing gasket is fitted to the flue, the flue is pushed through the hole until the rubber seal is past the external wall face and the flue is then pulled back.

edit: Cheers GM - far simpler put.

I always do a 5" core and thats 1 reason I like the WB

 

[Consumer]

Many thanks to everyone for all the answers.

Replies to points raised:

I don't think he is afraid of heights or he would not be suggesting roof modifications. More likely he wants to make a bit extra.

It's costing around 1500 parts and labour and he has to fit a condensate corrosion neutraliser gadget as once he has got as far as possible with plastic waste pipe the discharge will then exit via an existing wide bore copper pipe (impossible to change this) that ends up in the cast iron stack.

Not possible to fit a bracket anywhere outside without use of expensive scaffolding.

It would be just about possible to reach across to the outside of the terminal to put sealant around it should that be required.

I don't think he is trying to rip me off, just maybe over-cautious or not aware of the finer points of the regulations and he wanted to cover himself by making sure he does not get into any trouble with CORGI.

After all your replies I feel more confident with my own opinions in this matter. Thanks again.

 

[GasMan1965]

That is a very reasonable price

 

[gremlin16]

The outer collar self seals

Extract from Corgi essential gas safety fourth edition
" The wall face should be made good around the flue to stop the ingress of rain, draughts or product of combustion."

We always seal around flue on interior wall and exterior wall.We do use the plastic and rubber seals for cosmetic reasons.
The majority of wall are not smooth and the rubber seal will not make a proper seal.
Try using rubber seal on pebble dashed walls.

New build and total renovation now require testing for air tightness, this makes it important to provide a good seal on every pipe/flue that pass through walls.