condensing flue termination

[woody100]

hi all,
any installers having problems when installing condensing boilers with respect to the location to the neighbours boundary (pluming).
does the termination have to be 2.5m away from the boundry or 600mm
if we use a flue management kit ie go vertical up outside wall, can we then terminate within 2.5m of the boundry, will be interested to hear your views on this and your experiences in getting around this problem.

 

[ChrisR]

Sure. Its the best excuse for NOT fitting a steamer!.
It's 2.5 metres, if you're pointing at the boundary, not if parallel.

With the kits it's usually possible to point at an angle at least.

 

[woody100]

ok how what is the dimensions if parrallel ?

 

[JPC]

chris........i/we always thought it was 2.5m...(what a pain for terrace houses !)....but we have found out it is infact 600mm ...but with some restrictions attached....
i'm not corgi reg and i cant remember what they are but it's worth you checking again cos it makes live easier...as i'm sure u'll know

 

[ChrisR]

The exact figure for parallel will depend on the boiler manufacturer. That's probably the 600mm one. Aiming at your neighbour there would be wars with 600mm!
Definitely 2.5m if at 90º to the boundary.

 

[Paul Barker]

Actually if the plume goes over the boundary however far away you've goofed. A local court case found against the plumber who fitted a boiler at correct distances, but the products of combustion rotted the sofit /facia of next house. Plumber payed for repair and had to relocate boiler because he hadn't warned his customer of the possibility.

Basically we are going to have to get used to clambering on roofs again until more manufacturers come up with socks to divert products of combustion once exited from wall.

I can't think opf any excuses I could use if my local corgi inspector asked me why I'd fitted a band d boiler. I can't understand why they are still available.

 

[JPC]

dont want to labour a point but i've looked today at various makers installations instructions and all quote 600mm min distance from boundary is required.
i think the neighbour has to be told/warned/spoken to ? and the only poss problem would be enviromental nuisance ?.
i cant find a site that clarifies all and points out the poss problems but the 3 boiler makers sites quoted 600 !?

btw...thats is for terminal facing it...not parallel

 

[Paul Barker]

The letter of the corgi manual (and this is likely taken from British Standards) is that products of combustion should not cross adjoining boundaries. There is no distance spoecified to the bounday. This could be any distance, it may be that the plume extends 4 meters, in which case you can't put it there.

It does give a figure of 2m from an opening next door, but this distance is overridden by the must not cross boundaries rule.

the 600mm is purely a specification for the distance of a flat surface being positioned where it won't prevent the flue functioning correctly.

If you have already fallen foul you could devise a shield system to be placed greater than 600mm away from the terminal sufficient to prevent fumes being jetted across the boundary, casuing them to dissipate harmlessly on your side of the boundary. That is if your manyfacturer doesn't allow for a sock style diverter to be fitted to the flue, not many do.

Using the equivalent flue length data in the manufacturers instructions you could look into diverting the flu inside the building to terminate facing the back garden instead of the neighbour. You can't unfortunately divert the flue externally with the same system because the internal flue pipes are not designed for external use, they would require better standards of insulation.

 

[silverback]

The letter of the corgi manual (and this is likely taken from British Standards) is that products of combustion should not cross adjoining boundaries.

If this was the case many installations would be incorrect, products of combustion will often cross adjoining boundaries, the problem with condensing is that you can see the products of combustion, with standard efficient boilers you do not see the products, but they may still cross the adjoining boundary

 

[blahblah]

My understanding is that the 2.5m from facing boundary only applies in the exemption process and is not a reg, and applies to the pointed direction if a plume kit is used, ie you could go to 600mm in some circumstances and point it upwards if upwards has a clear 2.5m. As for parallel with the boundary, I reckon its still 300mm for a fan flue. Consideration of nuisance in all cases.

 

[ChrisR]

6 Flue terminal siting
It is necessary to site a condensing boiler flue terminal such that the plume of wet flue products does not impinge on or significantly affect the use of the householders’ dwelling and also the neighbouring buildings.
• For the purposes of the Boiler Installation Assessment Procedure AND the final boiler installation it is mandatory for the flue terminal to be sited in accordance with the requirements of Approved Document J. These requirements are specified for safety reasons and must always be followed.
•For the purposes of the Condensing Boiler Installation Assessment Procedure ONLY, more stringent requirements apply (given below) to reduce the possibility of nuisance to neighbouring buildings.
Key differences are:
• Wall terminals should be sited a minimum 2.5m from a facing wall, fence, building, or the property boundary – compared with 0.6m as given in Approved Document J (gas and oil boilers).
• Terminals must not be sited under a car port roof.
• More restrictive requirements apply for wall terminals sited at low level. ‘Low’ means a terminal sited below 2.1m.
This applies to:
– public foot ways and frequently used access routes – car parking spaces less than 2.5m from terminal
– patio (hard surface area). Where a plume diverter terminal is used, the distance should be measured in the direction of flue products.
Where wall terminals are difficult to site, extended flue options shown in Appendix B should be considered.

My take on that is that if you go closer than 2.5 metres and there's a complaint, you have a problem.

 

[blahblah]

I agree as long as the complaint is justifiable, but there will be occasions where getting closer and using the diverter will be ok. eg in a couple of weeks I've got one going in between two semis, on the flank wall, first floor. About 1m+ from boundary so two+ from the other house. No windows etc. If the diverter can point it upwards then I'll use one to save going through the roof- unless this thread convinces me otherwise!

 

[ChrisR]

That's fine, the 2.5 applies to 90º.

While on the subject has anyone seen how LOW they can go? Considering a flat where it would come out about 2.1m high, over a walkway.

 

[Paul Barker]

Chris is that taken from the British Standards? I don't have access to them without a 50 mile drive.

ps don't you think we could better serve the interestes of the public if British Standards were freely available, say in local libraries or cheap to purchase on cd, or downloadable on Acrobat?

 

[ChrisR]

No it's from the guff about trying to get away with not using a condenser ( ).
Couldn't agree more about the BS's. At least the building regs are free.

The reference is probably on the odpm site but I got it from
http://www.gas-news.co.uk/037022.pdf