Wood burner carbon monoxide posioning - a close shave.

[jezjez]

Just to share for the benefit of everyone,

We decided to spend Saturday night on board and sail sunday. Luckily for us it was a bit blowy for going off down to our favourite out of the way spot for the night. So we stayed on our mooring.
To stay warm we stoked up the fire in the wood burner - only our 3rd use of this attractive addition. Teh first 2 times we were timid and worried we might burn the boat down. This time we stoked it up well and hunkered down for the night.
The dog by the galley, us up in the foc'sle by the out-pipe.
I left a small gap in the door aft and forgot to check the forehatch.
At 5.30am the dog started whining. My wife said turn over and go back to sleep. I said we should get up and see to him. I got up and said went on deck. As I left the cabin I said "I've got a really bad headache on the top of my head." My wife said "so have I."
I guessed straight away we had not had enough ventilation but then my wifev got up and went to the loo. She then started to be sick and fainted - I must admit she was so blue/grey I thought she had died.
I dragged her on deck and called 999.
By the time teh ambulance arrived we had managed to get in the dinghy and ashore.
To cut to the chase we were taken to hospital and told we had 15 and 17% carbon monoxide poisoning and if we'd reached 20% we would have been taken to a eecompression chamber and treated as if we had the Bends like a diver.
We spent sunday in the hosipital on oxygen. We're now fine.
Teh dog is also fine and got a nice juicy bone.
Can I suggest - I felt really sleepy and this made me forget to check the forhatch for ventilation - but more so, have your woodburners checked for carbon monoxide output.
If we'd slept on we could have been in a lot worse trouble.
On the plus side, we live to sail another day.

 

[chrisc]

You are very lucky...good warning to others.

 

[Mukes]

Bloody hell Jez - lucky escape - glad all are OK.

A bit late but these were recommended in a review in PBO (I think) last year: http://www.sfdetection.com/ . I bought a CO detector direct from them for the boat.

 

[michael_w]

Thanks for the post.

Just to remind y'all that ANY HYDROCARBON FUEL, IF BURNT WITH INSUFFICENT OXYGEN WILL PRODUCE CARBON MONOXIDE.

Hydrocarbons are: wood, oil, gas both natural and lpg, coal, newspaper, charcoal, steak, pork chops, sausages etc etc.

Get a proper CO detector, not one of those dot gadgets.

 

[jezjez]

Marcus, have you got a wood burner on board or is it for your gas?

 

[jezjez]

I wish i was internet proficient enough to put a picture of the dog up on the site.

 

[graham]

Really glad it had a happy outcome. Not everyone is aware that you can get co from coal and wood as well as gas.

You may find that extending the flue pipe higher above the deck outside will help it draw better, A temporary extension that can be removed when your underway may be the answer but the joint must be airtight or it still wont draw properly.

.Im sure you have allready bought a CO detector after a scare like that.
Cheers Graham

 

[Mukes]

Jez - diesel burner fed from presurised tank - vented externally via flue. We take the detector home when the boat is ashore and use in the sitting room where we have a wood burner.

 

[jezjez]

The flue has an extension which seems to be chugging away nicely. The internal boards were all covered in a layer of grime (which is probably soot from the burner) when we bought the boat. Don't see any smoke in the boat except when opening door.
I obviously need to investigate the death trap we call our pride and joy!

 

[ccscott49]

Bloody lucky escape, glad you are all three fine! But a damn good wakeup call for all of us!

 

[Twister_Ken]

Glad you're still with us!

All the combustion (and part combustion) gases should be going out of the boat, via the flue, not into the boat. There must be a leak somewhere in the stove or flue, unless a downdraught is stopping the flue working properly. If the stove is leaking, it would probably make an admirable mooring sinker.

 

[jezjez]

There's nothing obvious but I shall detect.
My wife says that's the second time I tried to kill her. Last time she fell off a mountain and spent 3 months in hospital.
I swear I just happen to be adventerous and clumsy!

 

[Phoenix of Hamble]

What a good doggy!

I hope he gets at least a few more chewy meat laden bones yet!

 

[pete]

Ventilation is very important with any of these appliances.

Any products of combustion drawn out by the flue have to be replaced by fresh air getting to the heater and that should be far more than the appliance needs as you need this as well !


Pete

 

[ShipsWoofy]

for photos on the forum

photo tutor

 

[BSSOffice]

We have an article on solid fuel stoves as well as a warning about a recent fatal incident in Staffordshire and a link to our carbon monoxide leaflet on the home page of the Boat Safety Scheme website . Boaters can also check their own craft for obvious points of CO risks as well as for the ventilation requirements by using the information in chapter 8 of the BSS Essential Guide (2nd ed.) . Jez I hope you're able to identify the source(s) and cause(s) for certain so that can enjoy the boat with confidence for the future. Good luck and stay safe.

I'd be very grateful if you'd be willing to email me any pictures of the stove and its installation as well as any other details. We may use such information to inform other boaters about the dangers.

Kind regards
Rob @ BSS Office
bss.enquiries@boatsafetyscheme.com

 

[huldah]

It is important to realize that air flow up a flue can stop, if there is a wind induced vacumn, sucking air out of the cabin. The windows on the flue side of the boat need to be open. I grew up on a windy hillside, and this was a common problem with the old gas geezers. I remember my mother climbing in through a neighbour's window, to save an unconscious lad.

Often people would open the bathroom door, not realising that this allowed the vacumn at the front of the house to suck the fumes down the flue. The prevailing wind was normally at the back.

A balanced flue overcomes this problem, as the air pressure on the incoming air and the outgoing gases are equal.

Lastly, do remember that CO alarms can detect problems in the house as well. Mine went off when the Aga flue became blocked.

Philip

 

[chriscallender]

Scary indeed.

In my experience, these kind of flue problems can be worse once the fire dies back to the glowing embers and the flue starts to cool down. Plenty of CO still coming from the embers at this point, but not enough hot air/gas in the flue to draw well.

Given the early morning timing, I'd speculate that this is a likely explanation.

Chris

 

[jezjez]

Of course being boaty I should have known what would happen next:
We went to sleep at 10.30 - I tried to stay awake to see the tide turn at 11pm but was too tired - most likely because I had drunk 3 glasses of wine and the air was already depleting - so I didn't check the forehatch, but, i think, crucially as we turned with the tide this also meant the wind was with the tide - straight over the deck and probably sucking air out of the door instead of bringing a little air in as it had been when I checked it at 10.30pm.
I'm not entirely convinced we have a true leak - I think it was a badly ventilated system because of the above.
Dog now shut in the shed until life-saving skills required again (only joking). The story has done him well at work people have been bringing him bones for saving my wife, others have taken a swipe at him for saving me.

 

[jezjez]

Rob at BSS - I'm not much of an internet expert - I'll try to email a picture to you.