Stove Service / Repair

[Tacet]

On 07/12/2022 at 21:01, Jen-in-Wellies said:

It hasn't done it yet, but if your stove did go in to thermal runaway, how would you stop it?

As a kid alone when the Parkray ran away, the solution was to call uncle, who crawled across the room, shielding his face, holding the air control closing tool at full arm's length.  He just about reached the fire without frying himself.

 

When grandad had a chimney fire, he would take a bucket of water into the roofspace, open the metal door specially put in the flue, and slowly pour the water down.  With care, the water turned to steam and extinguished the fire without soaking the room.  You didn't want to call the fire brigade as, in order to help you remember to have the chimney swept in future, it would deliberately break roof liles and leave a hose down the chimney for an age.

[Jen-in-Wellies]

3 minutes ago, Tacet said:

You didn't want to call the fire brigade as, in order to help you remember to have the chimney swept in future, it would deliberately break roof liles and leave a hose down the chimney for an age.

A scene from my childhood. Walking home from school with a friend. "Oh look, a fire engine". A few steps later. "Oh look, it's outside Jen-in-Wellies house!". Yes, a chimney fire. Always stuck in my mind.

[Alan de Enfield]

3 hours ago, Jen-in-Wellies said:

Joking aside, this is serious. Under some circumstances, something can cause more draw on a stove than usual

 

A bit like a smaller version of the 'fire-storm' caused when bombing Dresden in Feb 1945.

 

 

[gatekrash]

30 minutes ago, Tacet said:

As a kid alone when the Parkray ran away, the solution was to call uncle, who crawled across the room, shielding his face, holding the air control closing tool at full arm's length.  He just about reached the fire without frying himself.

 

When grandad had a chimney fire, he would take a bucket of water into the roofspace, open the metal door specially put in the flue, and slowly pour the water down.  With care, the water turned to steam and extinguished the fire without soaking the room.  You didn't want to call the fire brigade as, in order to help you remember to have the chimney swept in future, it would deliberately break roof liles and leave a hose down the chimney for an age.

And also make a point of walking sooty, muddy boots all over the carpets if I remember rightly from my mates house when he had a chimbley fire.

 

We had one a couple of years ago at home, even though the chimbley is regularly swept. I realised something wasn't right when the stove thermometer went off the scale and the high temp silicon at the top of the flue pipe / closure plate join started to smoke ! I just shovelled the ash from the bottom on top of  the fire and closed everything down and 10 minutes later everything was cooling down. We didn't actually know it had been a fire at the top of the stack until the sweep came a couple of months later and could feel the deposits from the fire as he swept it. Although he said it wasn't a good thing to happen he did reckon that with the thickness of our 200 year old stone flue it wouldn't really have done any harm.

[Sea Dog]

3 hours ago, rusty69 said:

The last squirrel we bought had a small bracket that prevented the ashpan door from being opened unless the main door was opened too.

This is interesting. I love being able to open the bottom door on my Bubble to increase the draft when lighting or reviving the fire next morning. It takes minutes to get up to operating temperature, which I suppose would soon be a runaway if it wasn't being monitored. My single door Aarrow at home, on the other hand, stays in overnight just fine but takes an age to get back up to speed on a morning. I'd never have another single door stove, but I can see the safety aspect of it (or the interlock on the Squirrel). I'll stick with my free to operate lower door, but remember to remain vigilant.

[rusty69]

6 minutes ago, Sea Dog said:

This is interesting. I love being able to open the bottom door on my Bubble to increase the draft when lighting or reviving the fire next morning. It takes minutes to get up to operating temperature, which I suppose would soon be a runaway if it wasn't being monitored. My single door Aarrow at home, on the other hand, stays in overnight just fine but takes an age to get back up to speed on a morning. I'd never have another single door stove, but I can see the safety aspect of it (or the interlock on the Squirrel). I'll stick with my free to operate lower door, but remember to remain vigilant.

I like the ability to open the bottom door on the squirrel too, and is the reason I removed the bracket.

 

I can see why they added it though. Not only does it reduce the chance of thermal runaway occurring, it prevents the user heating up a cold stove too quickly, and cracking the delicate top plate, and perhaps the collar. 

 

I never leave ours unattended when opening the bottom door though, as it is all to easy to wonder off and do something else and forget all about it.

Edited December 9, 2022 by rusty69

[Sea Dog]

1 minute ago, rusty69 said:

...it prevents the user heating up a cold stove too quickly, and cracking the delicate top plate, and perhaps the collar. 

The top is perhaps more of an issue for cast stoves than steel, but the collar is something I hadn't thought of. 

[rusty69]

Just now, Sea Dog said:

The top is perhaps more of an issue for cast stoves than steel, but the collar is something I hadn't thought of. 

The only reason I know about cracking a collar is because I did exactly that when we first moved onboard. We were burning oak at the time, which probably wasn't the best idea.

[ditchcrawler]

16 minutes ago, Sea Dog said:

This is interesting. I love being able to open the bottom door on my Bubble to increase the draft when lighting or reviving the fire next morning. It takes minutes to get up to operating temperature, which I suppose would soon be a runaway if it wasn't being monitored. My single door Aarrow at home, on the other hand, stays in overnight just fine but takes an age to get back up to speed on a morning. I'd never have another single door stove, but I can see the safety aspect of it (or the interlock on the Squirrel). I'll stick with my free to operate lower door, but remember to remain vigilant.

Isn't that how the lady in stone died, due to the bottom being open https://www.bbc.co.uk/news/uk-england-stoke-staffordshire-43152705

[Sea Dog]

13 minutes ago, ditchcrawler said:

Isn't that how the lady in stone died, due to the bottom being open https://www.bbc.co.uk/news/uk-england-stoke-staffordshire-43152705

A salutary lesson to many. 

[Jen-in-Wellies]

Just to clarify, for those who've not seen one, the interlock Morso put on the two door Squirrels doesn't prevent you opening the ash door at all, only restricting the opening distance to around 5mm or so at the catch end when the main door is shut. Still good for a quick boost to the fire to get it going again, but less risk of a runaway, if you're distracted. Leave it open against the interlock too long though and the blast from the ecofan will prevent you reaching the stove to close the ash door! 😀

Edited December 9, 2022 by Jen-in-Wellies

[rusty69]

1 minute ago, Jen-in-Wellies said:

Just to clarify, for those who've not seen one, the interlock Morso put on the two door Squirrels doesn't prevent you opening the ash door at all, only restricting the opening distance to around 5mm or so at the catch end when the main door is shut. Still good for a quick boost to the fire to get it going again, but less risk of a runaway, if you're distracted. Leave it open against the interlock to long though and the blast from the ecofan will prevent you reaching the stove to close the ash door! 😀

 

Ah, OK. I said that it prevented it being opened earlier in the thread. My faulty memory at work.

 

Many apologies. 

[waterworks]

10 hours ago, Jen-in-Wellies said:

Joking aside, this is serious. Under some circumstances, something can cause more draw on a stove than usual. Perhaps a strong wind from a particular direction across the top of the chimney. With the 1410 Squirrel stoves that don't have the interlock fitted that prevents it, leaving the ash pan door fully open, with the main fire box door closed is a common way to get a thermal runaway. The extra draw pulls more air in to the fire, making it burn brighter. The extra heat from the fire and resulting convection flow through the stove draws yet more fresh air and oxygen in to the fire, causing it to burn brighter still. The extra heat draws yet more air and so on. Soon the entire cast iron stove body can be literally glowing red hot.

This can happen in minutes. It can lead to damage to the stove, destroyed grates, back boiler, cracked fire bricks (you have got these fitted, right?), cracked cast iron of the stove body, boiling water blown out of the heating header tank, etc. If you happen to be in a different part of the boat, or worse, not on board, or worse still, asleep, then you won't know it is going on and can't take steps to stop it. In boats, even those with stoves installed to the latest recommendations, there is combustable material closer to the stove than would be acceptable in a house. Many boats have stoves not installed to the recommendations. Worst case, the extra heat radiating from the stove ignites wood, or other material nearby, especially if you're not there to shut it down. The heat radiating off it will make approaching the stove harder to close vents, throw ash, salt, or whatever on the fire. People who have experienced a stove runaway have said it can happen with frightening speed.

 

This is why I've been banging on in this thread about your not having seals fitted being a bad idea and not to be recommended. You've got away with it till now, but it makes the stove much harder to control. The amount of air going in to the stove is variable, even with all the vents closed. Though the gaps around the doors is small, the length of the perimeters or door and ash pan means that the area is high and small changes in how well the door is closed can vary that area considerably. As the stove and doors heat up, they will expand and flex. That could increase the gap, making the problem worse, or might decrease it, there is no easy way of knowing. You've no way of shutting off all the air completely. This makes the probability of a runaway higher, possibly when you aren't in the room to deal with it and makes it harder to recover from if you are.

 

Seriously, please put the proper seals in. Your stove, boat, life and the lives of others are at risk without them. I'm being a stuck record about this in case some one else reads this thread and also thinks that leaving the door seals out on a Squirrel would be a good idea.

 

It takes about an hour to fit seals. Clean out the grooves that the rope sits in. I use a screwdriver on this to scrape out all the crud that tends to build up there. Use either the branded Morso rope and glue, or after market rope. If you're getting the cheaper seals off Ebay, or the like, go for rope sold as soft, rather than hard for Squirrel doors. If the door glass doesn't have the glass fibre seals, fit those too.  On a lived on boat, it needs doing every other year, I find. Apart from the rope itself degrading, it fills with ash over time and gets harder, making the door difficult to close.

 

Jen

 

Leaving the ash pan door open is nothing to do with having no seals though, that is a user mistake and can happen to the best sealed stove there is .

 

 

 

 

[Jen-in-Wellies]

2 hours ago, waterworks said:

Leaving the ash pan door open is nothing to do with having no seals though, that is a user mistake and can happen to the best sealed stove there is .

 

 

 

 

It is also a user mistake not to replace the seals that Morso supply the stove with when maintaining, or rebuilding. I'm leaving it at that. I've hopefully given any one else reading this who might consider doing the same thing pause, which was my hope, even if I can't persuade you.

[MtB]

I'd say several of the posts about stove runaway are incorrect. 

 

My own experience and definition of stove runaway (twice) is when the stove gets hot and the flue pull gets strong enough to overcome all the rope seals etc with EVERY VENT CLOSED. When this happens the stove gets hotter and hotter and there is nothing the boater can do to stop it and reverse the process other than smothering the fire, or, simply putting the chimney cap on! 

 

Last time I had it I was boating in weather like today, five degrees below zero and just as it was getting dark. I had the doors closed behind me and the slide drawn up close and I was marvelling at how warm I felt. Then I thought WTF and slid the hatch open and looked down. In the gloom inside the back cabin I could see the whole of the top of the Epping glowing medium red. Heart-stopping moment!! 

 

Ok I has actually left the tiny ash pan door ajar and forgotten whilst getting on with winter boating. I won't do THAT again....

 

 

[Jen-in-Wellies]

10 minutes ago, MtB said:

I'd say several of the posts about stove runaway are incorrect. 

 

My own experience and definition of stove runaway (twice) is when the stove gets hot and the flue pull gets strong enough to overcome all the rope seals etc with EVERY VENT CLOSED. When this happens the stove gets hotter and hotter and there is nothing the boater can do to stop it and reverse the process other than smothering the fire, or, simply putting the chimney cap on! 

 

Last time I had it I was boating in weather like today, five degrees below zero and just as it was getting dark. I had the doors closed behind me and the slide drawn up close and I was marvelling at how warm I felt. Then I thought WTF and slid the hatch open and looked down. In the gloom inside the back cabin I could see the whole of the top of the Epping glowing medium red. Heart-stopping moment!! 

 

Ok I has actually left the tiny ash pan door ajar and forgotten whilst getting on with winter boating. I won't do THAT again....

 

 

Yes, that's a better description. Once something has put the stove in to runaway, wind, seals, ash door, whatever, then options to get back control are limited as it becomes self sustaining and able to overcome the normal draught controls.

 

[Tony Brooks]

37 minutes ago, Jen-in-Wellies said:

Yes, that's a better description. Once something has put the stove in to runaway, wind, seals, ash door, whatever, then options to get back control are limited as it becomes self sustaining and able to overcome the normal draught controls.

 

 

And if the stove is designed to use seals but the boater decides they are not needed the runaway is likely to occur sooner, at a lower temperature, simply be cause the metal surfaces is not ground flat when seals are used as they would be on a stove designed not to use seals.

 

I found some of the advice in this topic very concerning and feel it was negligent and possibly based on just one stove installation.

Edited December 9, 2022 by Tony Brooks

[waterworks]

I just gave you my actual experience that the seals on my stove make no difference to it's normal operation. No doubt you have read about " runaway stoves " but has it actually happened with the doors closed ?

 

Explain how these ranges with no doors were fitted to back cabins without everyone dying of CO or runaway stoves ?

 

 

 

 

[tree monkey]

19 minutes ago, waterworks said:

I just gave you my actual experience that the seals on my stove make no difference to it's normal operation. No doubt you have read about " runaway stoves " but has it actually happened with the doors closed ?

 

Explain how these ranges with no doors were fitted to back cabins without everyone dying of CO or runaway stoves ?

 

 

 

 

Because they were designed that way, stoves with door seals were designed with those seals in mind.

Its your choice obviously but I wouldn't use a stove like a squirrel without properly working door seals

[Tony Brooks]

1 hour ago, waterworks said:

 

Explain how these ranges with no doors were fitted to back cabins without everyone dying of CO or runaway stoves ?

 

I think that the rectangle on the top half of the smoke box is a flue damper that is adjustable, so if it is opened it lets air into the flue and reduces or eliminates the fuel draw on the fire. So on this one you would adjust the burn rate by using the flue damper. I think the silver knob on the ash pan ids just that, a knob, and is not adjustable.

[ditchcrawler]

This photo just came up on Facebook 

[roland elsdon]

3 hours ago, waterworks said:

I just gave you my actual experience that the seals on my stove make no difference to it's normal operation. No doubt you have read about " runaway stoves " but has it actually happened with the doors closed ?

 

Explain how these ranges with no doors were fitted to back cabins without everyone dying of CO or runaway stoves ?

 

 

 

 

My belle portable as above had a cut steel sheet to go against that open vent, to reduce airflow. It aslo had a chimney damper in the flu above the smoke box.

you cant see the chimney damper in that picture

[David Mack]

4 hours ago, waterworks said:

The grate is higher than the top of the ashpan door, so there is a permanent uncontrolled air supply to the bottom of the fire, as well as through the firebars at the front.

There is a sliding damper in the bottom of the flue box operated by the vertical lever on the upper part of the flue box, which is the only control on the flue draught.

There are baffles in the gap between the outside of the oven and the inside of the stove casing so that the flue gases are drawn from the top of the fire then passed down and around the oven (to provide reasonably even heating), before rising up the back of the oven to the flue. That long and tortuous path requires quite a good flue draught to draw the gases through, so I wonder how well these stoves perform with the short flue on a narrowboat. They would be better in a house.

Edited December 10, 2022 by David Mack

[haggis]

2 hours ago, ditchcrawler said:

This photo just came up on Facebook 

There won't be much space left in the boat when the wrapping is taken off that tree ! 

[roland elsdon]

Belle portable on Thaxted worked well but needed furnacite to stay in overnight. Lovely enamelled version.

Unfortunately  cracks meant it was broken up on removal