Stove Installation

[Keajre]

Dear Friends,

 

I am planning on replacing my existing stove with a stove from the Chilli Penguin range.

 

The Flue collar on the stove itself is 5". All of the Chandlers I have spoken with only sell 4" or 4.5" flue pipe for inside the cabin.

 

I have two questions really:

 

a) Anyone got experience / opinions about using a 5" > 4.5" adapter and using a 4.5" flue pipe

b ) Twin Wall is recommended by BSS 8511 but I think its overkill

 

So Chilli Penguin offer a kit, for a very top price of £793!!! I think by using single wall can get the price down to £220. Speaking to experienced boat chandlers the opinion seems to be that BSS 8511 is really 'recommendations' only when it comes to single / twin wall flues and their relative distances to combustible surfaces.

 

Been using Single wall 5" for two years without any issues. Only reason I cant now use 5" again for the new stove, is that the roof collars don't accept 5" flues (or at least I haven't managed to find any).

 

Just spoken to a boat safety person (who issue the certificates). Frankly shocking how little they seem to know about BSS 8511 or even really any clear advise about how a stove flue / chimney should be constructed.

 

Any advise would be really appreciated, read so many forums, spoken to so many people and reading BSS 8511 and not getting much clarity.

 

many Thanks

Stuart

Edited August 10, 2016 by Keajre

[mross]

In theory a twin wall should help the fire to draw and let you getaway with a shorter chimney...........Sorry to be slightly off topic.

[Keajre]

I do agree, but possible that benefit would be almost imperceivable? Been using single on inside, and twin outside for the chimney for some years. Sometimes with too much draw! So since its much more expensive, rarther stick to single, but only if its considered safe.

[rjasmith]

Stuart,

 

This is a small point perhaps but you consistently write "BSS 8511". Does this mean you believe this Code of Practice is a Boat Safety Scheme production?

 

It isn't!! Maybe this is why some the BSS folks you've spoken to are not word perfect on it!

 

The correct ref no for the document is BS (one "S") 8511 because it was produced by British Standards (BS), not the Boat Safety Scheme (BSS) although I'm sure some BSS people may have made contributions to the BS drafting team back in 2010.

 

Also I'll add that the document has no connection with the Recreational Craft Directive either! It is not an RCD Harmonised Standard which all have to be ISOs that are specially produced to tie in with the RCD Essential Requirements.

 

The BS 8511 CoP was produced after a recommedation by the Marine Accident Investigation Branch (MAIB) that such guidance didn't exist as a British Standard and should be produced, following the Lindy Lou fatal accident.

 

Of course the BSS do recommend it as best practice and commercial stove installers will invariably follow it in full, insurance companies may also prefer it to be followed, but it is not mandatory!

 

Not quite sure what you mean in your last sentence - have you read BS 8511? You can do for free if you log on to Manchester City library website and go to this page. Click on the "British Standards Online" link on that page which will take you to the BSOL website free of charge (thank you MCL!!) and then type "8511" in the BSOL search box. When you get a list of stds matching "8511" you want the "8511:2010" entry. DON'T click "View Details but go to the little Adobe icon on the far right and click that.

 

The full BS 8511 doc will then download. You can view it but not save or print it, unless you want to pay BS £182!

 

Opinions on CWDF seem to be split about whether to go for insulated or non insulated flues. There has been a study by Soliftec suggesting that fuel is saved with an insulated flue. This seems counter intuitive perhaps.

 

I've gone for a conventional non insulated flue but then mine is 4" so I haven't had your problem!

 

Richard

[mross]

Normally my flue is too hot to touch so it must be full of hot gases. Perhaps the twin wall is better when you bank the fire at night when my flue is less hot.

[Keajre]

Hi Richard,

 

I didn't know that, thank you for that correction. So BSS is the boat safety scheme and BS is British Standard. BS 8511 having no connection with Recreational Craft Directive. That is useful information to me.

 

The practitioner of BSS who I spoke to today was quite vague about what would be acceptable in terms of flue installation. I have not read the BS 8511, but i have seen the diagram by Soliftec. Think I will stick to single wall. However concerned that the stove manufacturer saying 5" is needed, and using a 4.5" flue with adapter would not be acceptable.

 

Thanks

[Chewbacka]

I used single wall from the stove to about 9" below the roof, then twin wall through the roof and a twin wall chimney.

My thinking was that the single would heat the boat and the twin wall going through the roof would protect the roof lining against heat. Outside the twin wall would help keep the gasses hot and so ensure a good draught.

It works for me, but then it may also have worked well with single wall for the lot and saved me some money as well.

That said, if I was doing it again I would do the same again.

[Tiggs]

We had a stove on a boat with a reduction adaptor. The reason I believed that it was OK is that we also had some extra refectory bricks in the stove to reduce the maximum fire size. Most solid fuel stoves are too big for boats and you can end up with the doors open in winter when it's -8 outside. Anyway the boat safety inspector never commented on it.

[WotEver]

The only relevant BSS Reg that I can see states that the flue "must show no obvious signs of... any modifications to the flue/exhaust not in accordance with the appliance manufacturer's recommendations."

 

An awkward inspector could see the flue reducer and ask for written proof that the manufacturer approved such reducer.

 

8.10.2 here: http://www.boatsafetyscheme.org/media/268789/ecp-private-boats-ed3_rev2_apr2015_public_final.pdf

 

Tony

 

Afaik there is nothing in the regs stating that twin wall must be used.

[David Mack]

Been using Single wall 5" for two years without any issues. Only reason I cant now use 5" again for the new stove, is that the roof collars don't accept 5" flues (or at least I haven't managed to find any).

If you already have a 5" flue, why can't you use the existing chimney collar, or indeed the existing 5" flue pipe?

[Keajre]

I used single wall from the stove to about 9" below the roof, then twin wall through the roof and a twin wall chimney.

My thinking was that the single would heat the boat and the twin wall going through the roof would protect the roof lining against heat. Outside the twin wall would help keep the gasses hot and so ensure a good draught.

It works for me, but then it may also have worked well with single wall for the lot and saved me some money as well.

That said, if I was doing it again I would do the same again.

Hello, is your chimney removable? If so, would be interested to know what size flue you are using and what type of roof collar you use. Makes sense to me to have twin wall chimney, roof collar, then twin wall on the inside some inches below the roof not the cabin to protect the roof. Then have single wall and have it a sensible distance from conbustables.

 

I guess it's possible to sell twin wall to twin wall 5" roof collars?

The only relevant BSS Reg that I can see states that the flue "must show no obvious signs of... any modifications to the flue/exhaust not in accordance with the appliance manufacturer's recommendations."

An awkward inspector could see the flue reducer and ask for written proof that the manufacturer approved such reducer.

8.10.2 here: http://www.boatsafetyscheme.org/media/268789/ecp-private-boats-ed3_rev2_apr2015_public_final.pdf

Tony

Afaik there is nothing in the regs stating that twin wall must be used.

Thanks for the link, didn't know that was publically available! I didn't see that quote in 8.10.2?

[WotEver]

Thanks for the link, didn't know that was publically available! I didn't see that quote in 8.10.2?

It's a contraction of the first and fourth paragraphs in the right hand box.

 

Tony

[bizzard]

There needs to be a gap all around where the flue pipe passes through the roof collar for packing, expansion and contraction. So if you have a 5'' flue pipe you would need a collar with at least a 5.1/2'' hole through it which would leave a 1/4'' wide gap all around for packing. A 6'' hole through the collar would be better, leaving a 1/2'' gap all around.

[Keajre]

In my mind what would be ideal would be:

 

A) 5" flue pipe to match 5" stove

roof collar to accept 5" pipe and allow 6" twin wall chimney to connect

 

Anyone know where I can buy a 5 1/2" OD roof collar? Can't seem to find one

[WotEver]

Anyone know where I can buy a 5 1/2" OD roof collar? Can't seem to find one

 

Surely a 6" would be ideal? That gives you ½" clearance for rope and silicon. 5½" would only allow ¼" clearance which would be a bit tight.

 

Tony

[Keajre]

Yes agreed