Stove Service / Repair

[bizzard]

On 01/12/2022 at 13:07, pearley said:

Ship Shape Stove Services

 

https://www.shipshape1.co.uk/

 

I know Des and Sarah, I recommend Ship Shape Stoves.

[waterworks]

13 hours ago, roland elsdon said:

Ive been on boats since 1979 with solidfuel stoves and in spite of 2 co alarms and smoke detectors got caught out last year.

Replaced the stove seal and doubled the insulation behind it as part of changing its orientation.

Cleaned chimney. Smoke pellet allgood.

 

Few nights later in strong wind stove ran away. Boiling kettle  whistle alerted me.

As i looked to the stove i could see reflection of flames-on the new silicate boards.

No smoke alarm no co alarm.

The string seal had unglued under the catch allowing an inch or so to fold into the fire rather than sit in the grove.

Stove was pretty hot even though bottom damper was 98% closed.

 

i always leave a full kettle on the fire. 
 

An inch gap in the door would be no more air the normal running. 

[jonathanA]

On 04/12/2022 at 13:09, waterworks said:

My experience with rebuilding and burning my own stoves is that door seals make no practice difference, there is no point when the fire needs no air so the air coming through the doors can just be subtracted from the air controls. When burning stoves run at negative pressire so suck air in through any gap, they dont emit smoke .

 

If you want to seal the doors against smoke blowing back down the flue due to the don't then you can't since you already have big holes in the stove for your air controls. 

 

My Morso Squirrel I built from scratch was perfectly sealed on every joint, now the door seals are expired and gone and it makes no practical difference. I have a CO monitor next to it that has never detected anything.

Guess we all have slightly different experiences.  The bss includes a  check on door seals and unintended gaps or cracks   (check 8.10.2)( someone will be along who will be able to quote chapter & verse. )

 

I've found that if you want to be able to close a stove right down then having well fitting doors, air controls and well sealed joints are needed. More of an issue with the longer flues on domestic installs but as Roland's example shows can be a problem on boats. 

1 hour ago, waterworks said:

An inch gap in the door would be no more air the normal running. 

And would be a bss fail on a hire boat and an advisory on a private boat I think

Rightly or wrongly the bss think there is an issue with door seals cracks etc....

[Tony Brooks]

If I don't fully close the door on the "cam" on my little stove at home so it [pulls up the door seal the fire starts to run away. That is with only a few mm extra gap. Likewise, with the door open for de-ashing or refueling the fire starts to roar away. The stove on the boat did the same. I can only think there is something odd about @waterworks flue or stove.

 

(Small Hunter at home, Brunel on the boat,  The Prakray did the same at home when we had one, but that one used a machined cast iron face to face to seal the door, one had to set the gap with feelers, I can't remember what the maximum gap was bout it was only a few thou.)

[roland elsdon]

11 hours ago, waterworks said:

An inch gap in the door would be no more air the normal running. 

Not on that stove. A couple of mm is enough to keep it in all night. We burn 8 hr briquettes. With any more than a mm or so of air they become 4 hr. With bottom damper open they can be gone in 90 mins. We fought this stove long and hard until we started using briquette. It would go out or burn away most of the time.

 

[waterworks]

17 hours ago, Tony Brooks said:

If I don't fully close the door on the "cam" on my little stove at home so it [pulls up the door seal the fire starts to run away. That is with only a few mm extra gap. Likewise, with the door open for de-ashing or refueling the fire starts to roar away. The stove on the boat did the same. I can only think there is something odd about @waterworks flue or stove.

 

(Small Hunter at home, Brunel on the boat,  The Prakray did the same at home when we had one, but that one used a machined cast iron face to face to seal the door, one had to set the gap with feelers, I can't remember what the maximum gap was bout it was only a few thou.)

Standard Morso squirrel, there are no door seals and it runs on coal or wood just fine and the air controls are never fully, I just removed the extra firebricks I put in to restrict the capacity for the warmer months, there is no runaway in fact quite the opposite. 

[Jen-in-Wellies]

2 hours ago, waterworks said:

Standard Morso squirrel, there are no door seals and it runs on coal or wood just fine and the air controls are never fully, I just removed the extra firebricks I put in to restrict the capacity for the warmer months, there is no runaway in fact quite the opposite. 

Possibly the flue is restricted? With a Squirrel stove, I sometimes get a build up of very hard, almost concrete like clinker in the flue pipe about six inches above the stove. As it restricts the flue gas flow, you need to open the vents more and more to get any sort of combustion.

Also, what is your flue pipe diameter? How many and what angle are any bends in it?

Trying to understand how your experience of squirrel stoves with poor, or damaged, let alone missing seals differs from every one else I know with these stoves.

[jonathanA]

People sometimes don't think to clear the detritus from the baffle plate (If fitted) that can also cause a restriction, surprising how much stuff collects on them....

[bizzard]

If the Morso has no back boiler then it probably has a sort off half moon throat plate held up by two nuts. This should be removed for short flue pipes like used on boats.  Concrete like crud in the flue pipe is caused by feeding the fire with wet or damp smokeless fuel. The fuels binder mixes with the moisure and goes like cement in the flue especially on slow burn overnight. Try and dry the fuel before using it.

 

 

 

[waterworks]

3 hours ago, Jen-in-Wellies said:

Possibly the flue is restricted? With a Squirrel stove, I sometimes get a build up of very hard, almost concrete like clinker in the flue pipe about six inches above the stove. As it restricts the flue gas flow, you need to open the vents more and more to get any sort of combustion.

Also, what is your flue pipe diameter? How many and what angle are any bends in it?

Trying to understand how your experience of squirrel stoves with poor, or damaged, let alone missing seals differs from every one else I know with these stoves.

Straight 5" flue, no baffle plate, zero soot buildup.

[Jen-in-Wellies]

2 hours ago, waterworks said:

Straight 5" flue, no baffle plate, zero soot buildup.

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

[bizzard]

Keep a bag of salt handy to kill it quickly.

[MtB]

47 minutes ago, bizzard said:

Keep a bag of salt handy to kill it quickly.

 

Never mind salt, just shovel the ash from the ash pan underneath onto the top of the coals. This is how I've quelled a runaway stove a couple of times over the years. Works a treat. 

[bizzard]

10 hours ago, MtB said:

 

Never mind salt, just shovel the ash from the ash pan underneath onto the top of the coals. This is how I've quelled a runaway stove a couple of times over the years. Works a treat. 

But what if you've just emptied it in the cut and the soil outside is frozen solid.

[MtB]

1 hour ago, bizzard said:

But what if you've just emptied it in the cut and the soil outside is frozen solid.

 

In that case, salt is excellent. Or sugar. Or sand. 

 

Just don't pour water down the chimberly. DAMHIK this is a truely terrible idea.

 

 

[Iain_S]

5 hours ago, MtB said:

 

In that case, salt is excellent. Or sugar. Or sand. 

 

Just don't pour water down the chimberly. DAMHIK this is a truely terrible idea.

 

 

Or if you are doing that, very slow and a fine spray. That used to be (and probably still is, just not needed as often) the standard Fire Service way of extinguishing chimney fires.

[tree monkey]

5 hours ago, MtB said:

 

In that case, salt is excellent. Or sugar. Or sand. 

 

Just don't pour water down the chimberly. DAMHIK this is a truely terrible idea.

 

 

Or sugar in fact, it burns lovely 

[waterworks]

23 hours ago, 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?

What's a " thermal runaway " ?

 

 

[ditchcrawler]

2 hours ago, waterworks said:

What's a " thermal runaway " ?

 

 

Its the nuclear pile that drives the ecofan, I thought everyone knew about nuclear reactors going into thermal runaway 🤑

[roland elsdon]

Thermal runaway is when there is a shrill whistle from the kettle on the fire, then the ecofan takes off from the range and flies through the window, sinking into the canal. ( doesnt matter ‘they dont work’ -  see short previous thread for reference)

Then the central heating boils sending plumes of superheated antifreeze  into the airing cupboard, containing your white work shirts.

Shortly after the fire goes out, as the grate collapses into the ash pan, and the dog steals the duvet because the snow is now coming in through the broken window.

When you arise the fire is a distorted wreck caused by overheating, you get up go outside and discover the paint on the roof is destroyed by the  incandescent lava from the volcanic output of the stove.

You fire up the diesel central heating only to discover that allowing someone illiterate to ‘fill your water tank mr’ was not the best idea, while you were wrestling with the nappies that some helpful person had put down the sani station.

 

You crawl to the canal bridge knee deep in mud to discover that someone from extinction rebellion have borrowed the air from your car tyres. Shouting to the heavens ‘its a hybrid’ fails to impress the god of your choice as to your green credentials. Tyres remain flat. Green potential of your vehicle extending to no pump to save weight.

The AA are on strike because everyone is using their car to get to work coz of the rail strike.

 

A fairly normal day then.

Dont let your stove run away its bad.

[Jen-in-Wellies]

11 hours ago, waterworks said:

What's a " thermal runaway " ?

 

 

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

 

Edited December 9, 2022 by Jen-in-Wellies

[rusty69]

The last squirrel we bought had a small bracket that prevented the ashpan door from being opened unless the main door was opened too. The bottom air vent also had restricted movement compared to previous models too. Presumably in an attempt to reduce thermal runaway. 

[Jen-in-Wellies]

3 minutes 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. The bottom air vent also had restricted movement compared to previous models too. Presumably in an attempt to reduce thermal runaway. 

This is what I described as an interlock in the previous post. You are right, runaway prevention was the reason they started fitting them. Mines got one. Same with the bottom air vent restricted opening (about 1.5 turns on mine). Still enough to get the fire toasty.

Edited December 9, 2022 by Jen-in-Wellies

[rusty69]

Just now, Jen-in-Wellies said:

This is what I described as an interlock in the previous post. You are right, runaway prevention was the reason they started fitting them. Mines got one. Same with the bottom air vent restricted opening (about 1.5 turns on mine).

Oh right,is that what they are called. 

 

I'm afraid I removed them both. 

[Jen-in-Wellies]

Just now, rusty69 said:

Oh right,is that what they are called. 

 

I'm afraid I removed them both. 

That's what I called it, but no idea if that is the official name, which would be in Danish in any case! A lot of people do remove them. I did consider it, but left it in place in the end.