Hot ash setting of the carbon monoxide detector?

[Alan de Enfield]

22 minutes ago, robtheplod said:

Is CO lighter than air?  I'm assuming so as CO detectors tend to be high up.....

 

Very similar density and it just floats about at any height.

It is genrally Smoke alarms that are 'high-up' on the ceiling as the heated smoke rises.

 

The installation instructions say that the CO alarm should be placed 'near your bed at head height when lying down'  which is obviously the height you are breathing at.

 

Other instructions for other rooms.

 

The alarm needs to remain in the open air so it’s monitoring the same air that everyone is inhaling, so make sure it isn’t blocked by furniture. And in bedrooms and living rooms, it may be better to place it at the same height as people sleeping or sitting.

However, it is possible to fix them to the ceiling too. In fact, if you have a combination smoke and CO alarm, it’s the best place to install it. But you will need to make sure it’s at least 30cm away from walls or other obstructions, like light fittings.

[Col_T]

We don't even try to leave our multi-fuel burner 'in' over-night e.g. we just close it all right down and let it burn itself out. The result is cold ash in the morning, which goes straight into the tippy.

 

Hopefully there are no dangers with this approach!?

 

 

[Murflynn]

2 hours ago, robtheplod said:

Is CO lighter than air?  I'm assuming so as CO detectors tend to be high up.....

 

molecular weights:

 

air - a mixture of :

O2 ... 32

N2 ... 28

 

CO ... 28

 

effectively the same in practice, so the molecules just mix indiscriminately   ...........  in still air there will be a marginally higher concentration at high level.

[ditchcrawler]

1 hour ago, Col_T said:

We don't even try to leave our multi-fuel burner 'in' over-night e.g. we just close it all right down and let it burn itself out. The result is cold ash in the morning, which goes straight into the tippy.

 

Hopefully there are no dangers with this approach!?

 

 

[tree monkey]

17 hours ago, nicknorman said:

Our CO alarm has a digital display which is hopefully always on zero. But recently it started to show 10, 15, maybe 20 ppm for a long time after the stove had been refuelled. Not enough to activate the alarm, but not comforting! We’d had this problem before, flue partially blocked. And anyway I’d noticed it wasn’t lighting and drawing very well. But really difficult to clear out properly because it has a bend near the top.

 

So last week I finally bit the bullet and completely removed the cast iron flue. Which wasn’t particularly easy! Wedged really tightly into the roof collar with masses of glass rope, so I had to use a drill between collar and flue. It must have taken a couple of hours to get all the glass rope out.

 

As expected, the lower portion was severely congested with concrete-like stuff. Probably 1/2 the diameter was lost which (if my mental arithmetic is correct) means 3/4 of the area was lost. It required a hammer and chisel to dislodge, and when that ran out of reach, a mooring stake and mooring hammer. Fortunately just as the stake ran to the limit of its reach, the last lumps fell out. Weirdly there was a step change where it just stopped, about 1/3rd of the way up.
Several kilos of “concrete”removed. Flue replaced with lots of glass rope and Envirograf 1200 degC silicone. Hopefully we can now add fuel to the stove without gassing ourselves!

 

I don’t know if there is a way to stop that build up again, otherwise I’ll have to repeat  the process in another 10 years!

Similar to yours mine has a slight bend in the flu and the crud accumulates there as well, although possibly due to the fact my fire is on constantly from about Oct to April it builds up faster than every 10yrs.

 

Anyway to the point, I was chipping away at the crud this summer and something distracted me, a brew or a snooze or something so I didn't finish the job, completely forgot until a few weeks into fire season, much swearing ensues and onto Google for more avoidance and I spotted this stuff

 

https://www.homecareessentials.co.uk/categories/homecare-products/fireside-products/chimney-and-flue-cleaners/product/hotspot-flue-free-chimney-cleaner-750g

 

I normally ignore wonder powders or miracle cures but it was cold and I didn't want to let the fire go out, now it is always a possibility that the remaining crud fell out of the flue because of the recent vigorous chipping or it was the wonder powder but fall out it did and I now have a completely crud free flu.

 

 

 

[Guest]

6 hours ago, Alan de Enfield said:

 

Very similar density and it just floats about at any height.

It is genrally Smoke alarms that are 'high-up' on the ceiling as the heated smoke rises.

 

The installation instructions say that the CO alarm should be placed 'near your bed at head height when lying down'  which is obviously the height you are breathing at.

 

Other instructions for other rooms.

 

The alarm needs to remain in the open air so it’s monitoring the same air that everyone is inhaling, so make sure it isn’t blocked by furniture. And in bedrooms and living rooms, it may be better to place it at the same height as people sleeping or sitting.

However, it is possible to fix them to the ceiling too. In fact, if you have a combination smoke and CO alarm, it’s the best place to install it. But you will need to make sure it’s at least 30cm away from walls or other obstructions, like light fittings.

 

Not in all cases' it depends on the alarm.

 

On ours it states to fix the alarm at a height which makes it easy to read the digital readout. In both our house and caravan (and as was on the boat) this is higher than head height when sleeping.

[Guest]

5 hours ago, Col_T said:

We don't even try to leave our multi-fuel burner 'in' over-night e.g. we just close it all right down and let it burn itself out. The result is cold ash in the morning, which goes straight into the tippy.

 

Hopefully there are no dangers with this approach!?

 

 

 

This should be fine if indeed you have actually closed all the vents fully,

 

We do this at home much of the time as keeping the stove in seems to create a lot of ash which takes a lot of cleaning out.

 

We sometimes (depending on what time we turn in) find a few glowing embers in the grate the next morning but our Digital CO alarm (in the same room) never gives a peak level reading that would give cause for any concern.

Edited December 7, 2021 by The Happy Nomad

[Simon2021]

On 06/12/2021 at 21:28, F DRAYKE said:

We had the same trouble with our CO2 alarm going off till we got one of these https://www.onbuy.com/gb/valiant-fireside-tidy-ash-transporter-black-gloss-steel-storage-box-fir240~c13671~p7482999/?exta=gshp&stat=eyJpcCI6IjI5Ljk5MDAiLCJkcCI6bnVsbCwibGlkIjo3NjA3ODY1MiwicyI6bnVsbCwidCI6MTYzODc0NzYzMSwiYm1jIjoiMTAuMCJ9&lid=76078652&gclid=CjwKCAiAhreNBhAYEiwAFGGKPHvVfXCb9vQ6jdIu3DObVNqbZ-yIXeoBXxoOI-zpxj1Agmlr9UByYRoCulMQAvD_BwE

Not had any trouble since. 

I would also say to check you alarms and fire extinguishers at least once a month. With the fire extinguishers, take them off of their mounting and turn them upside down a few time to shake up the powder inside. 

Thanks for the recommendation. I've ordered one.

[blackrose]

On 06/12/2021 at 21:11, MtB said:

 

Yep, i should have said so. 

 

I should also have pointed out that rather than a bucket (with lid or not), a "Tommy Tippy" ash container is the thing to use to minimise CO risk. Or one of the many clones around nowadays.

 

With these, you can put the whole ash pan inside it filled with the ash, close the lid and carry the whole lot outside. Open the lid outside and get the pan out leaving the ash inside. much cleaner than tipping ash into a bucket inside the boat. Then leave the container containing the ash outside with the lid closed to cool and dispose of later once cold. that's how I use mine anyway.

 

 

 

https://www.ebay.co.uk/itm/265313196429?epid=1374579566&hash=item3dc5e6198d:g:oKIAAOSwvVxhQMah

 

I've got one of these these things but I never use it. The ash pan for my double door 9kW stove is quite big and the oversized carrier is just too cumbersome.

[Scholar Gypsy]

19 hours ago, Murflynn said:

 

molecular weights:

 

air - a mixture of :

O2 ... 32

N2 ... 28

 

CO ... 28

 

effectively the same in practice, so the molecules just mix indiscriminately   ...........  in still air there will be a marginally higher concentration at high level.

 

Here's an interesting article I found on stratification.  The takehome message is that you should put the sensor at head height, as that is where you breathe in. Brownian motion will achieve pretty thorough mixing of CO with the other gases in air.

https://chemdaq.blogspot.com/2012/09/gas-stratification-is-not-relevant-to.html

>>>>

 

A recent MAIB bulletin, there are several more detailed reports on individual cases.

 

https://www.gov.uk/maib-reports/safety-warning-about-carbon-monoxide-poisoning-after-the-loss-of-2-lives-on-the-motor-cruiser-diversion

>>>>

 

I also got a reading of 10 a few weeks ago. Time to replace the mastic/fire cement around the top of the stove.

Edited December 8, 2021 by Scholar Gypsy

[MrBadger]

I have just had a similar thing happen, I am very new to boating. CO alarm went off - definitely not batteries and not a gas leak, which I checked (I don't think that would set it off anyway) but my fire was open and coals slowly burning. I havent cleaned my flue and I had the ash tray at the bottom open too...thinking it must be that. Opened windows etc not going off anymore..worrying though this thread has taught me to get my butt in gear to clean out the fire and not always leave the ash door open below the main door too

 

[Guest]

18 minutes ago, MrBadger said:

I have just had a similar thing happen, I am very new to boating. CO alarm went off - definitely not batteries and not a gas leak, which I checked (I don't think that would set it off anyway) but my fire was open and coals slowly burning. I havent cleaned my flue and I had the ash tray at the bottom open too...thinking it must be that. Opened windows etc not going off anymore..worrying though this thread has taught me to get my butt in gear to clean out the fire and not always leave the ash door open below the main door too

 

 

Just to confirm, an LPG gas leak will not activate a CO alarm.

 

(Apart from anything else LPG will sink down and accumulate in the bilges of your boat).

[blackrose]

1 hour ago, MrBadger said:

but my fire was open and coals slowly burning. I havent cleaned my flue and I had the ash tray at the bottom open too...thinking it must be that. 

 

Yes, try closing the stove door when the stove is lit!

 

You might be able to run the stove with the main door open using it like an open fire in a 2 storey house where the flue is very long, but you can't do that on a boat because of the short flue & chimney - the stove simply doesn't have sufficient draw to use it like that.

 

 

Edited October 18, 2023 by blackrose

[BlueStringPudding]

The same thing happened to me when I was relatively new to boating. I would take the ash outside onto the back deck and pour it into a metal bucket there, to cool down. One night my CO alarm went off. It seemed that the carbon monoxide from the bucket of ash was making its way into the boat through the vents in the rear door. I had a dig around in the bucket and despite the grey ash on top, underneath it was glowing red. 

I don't leave my ash bucket on the boat anymore 

[Mad Harold]

On 06/12/2021 at 22:20, Alan de Enfield said:

 

Also remember (fortunately) that it is NOT ONLY CO that sets off the CO alarm.

 

Middle of the night CO alarm goes off, hunt around the boat, nothing on, no fire, no gas burners - nothing.

Open windows and wave a towel about until the alarm stops so decide it must just be an alarm fault.

 

About an hour later (fast asleep) and the alarm goes off again. repeat waving the towel about until it stops.

Decide to have a look in the engine room, remove the steps that give entry under the floor and crawl into the walkway.

Eyes start to burn, throat gets sore (no smells - just 'taste')

Track the source down to one of the (six) 230Ah batteries (big thing weighs 55kgs) that is looking like a rugby ball with the ends distended. The battery is BOILING hot and I cannot even touch that terminals.

Got the spanners and disconnected the battery from the bank.

 

Heat unbearable, fumes choking.

 

Switched on the Engine room blowers, opened all doors and windows and waved the towel about again.

 

Eventually got back to bed for a couple of hours sleep.

All the following day the battery was too hot to handle and I was a bit concerned about it surviving being dragged and lifted out of the engine room.

Eventually it cooled down enough to get it out.

 

I reckon we were only 'seconds' away from a catastrophic battery explosion and saved only by the CO alarm sensing the fumes generated by the battery having an internal short.

I fitted a 5W solar panel to my boat. The advice I was given was that such a small panel would only keep up with the natural discharge rate of the battery,so no need for a charge controller.

This advice proved wrong!

Going to the boat after a couple of days of sun, the co alarm was going off.

Putting my multimeter on the battery it indicated 16.6 volts.

Fitted a cheapie e bay charge controller and no further problems.

 

[ditchcrawler]

16 hours ago, MrBadger said:

I have just had a similar thing happen, I am very new to boating. CO alarm went off - definitely not batteries and not a gas leak, which I checked (I don't think that would set it off anyway) but my fire was open and coals slowly burning. I havent cleaned my flue and I had the ash tray at the bottom open too...thinking it must be that. Opened windows etc not going off anymore..worrying though this thread has taught me to get my butt in gear to clean out the fire and not always leave the ash door open below the main door too

 

Leaving the ash door open can lead to the fire running away and setting fire to your boat, ends up like a Furnace

[The Black Jack]

On 06/12/2021 at 15:39, BlueStringPudding said:

I set off my CO alarms once by leaving the ash bucket on the OUTSIDE stern deck step. Unbeknownst to me, despite the grey ash on the top, the ash beneath was getting very hot and glowing orange. It was enough to spew out carbon monoxide that came in through the vents in the stern doors and that set off the alarms.

 

Ash gets taken outside, well away from the doors, now. And when cooled, dumped into a larger bucket on the deck to be disposed of later. 

 

Please be mindful not to leave buckets of ash on the bank if near to the towpath. Passers-by, especially after dark or if skirting round puddles, branches or around other towpath users, might trip over it creating not just the risk of fall-injuries but potential burn injuries too. 

Why not cool ash completely by adding water?

[booke23]

16 minutes ago, Mike A R Powell said:

Why not cool ash completely by adding water?

 

If you add water to hot ash, it immediately turns to steam in a large plume and blasts ash all over the place.

Edited November 8, 2023 by booke23

[MtB]

38 minutes ago, Mike A R Powell said:

Why not cool ash completely by adding water?

 

Why not just take it outside?!

 

 

[The Black Jack]

Yes that's fine so long as someone doesn't end up starting a grass fire with it.

[Ianws]

33 minutes ago, booke23 said:

 

If you add water to hot ash, it immediately turns to steam in a large plume and blasts ash all over the place.

Steam burns are extremely nasty.

[MtB]

2 minutes ago, Mike A R Powell said:

Yes that's fine so long as someone doesn't end up starting a grass fire with it.

 

Do it your way then, and fill your boat with steam and clouds of ash! 

 

 

[The Black Jack]

The idea was to take the ash out then extinguish it....outside.

7 minutes ago, Ianws said:

Steam burns are extremely nasty.

Ash into water not the other way around.

[booke23]

12 minutes ago, Mike A R Powell said:

The idea was to take the ash out then extinguish it....outside.

Ash into water not the other way around.

 

That's not what you originally suggested.

 

1 hour ago, Mike A R Powell said:

Why not cool ash completely by adding water?

 

Whatever way you slice it, adding ash to water or water to ash is unwise. Just put the ash in a metal container....you can even buy metal ash containers with lids and handles to facilitate this. Then put the ash container somewhere to cool. KISS

[The Black Jack]

OK I'm persuaded not to add water. Just make sure your hot ashes are off the boat and don't burn anyone or start a fire. Crikey! This forum is more combative than Twitter!