Squirrel Morso help please

[KEWalker]

Hi I am new to narrow boats. I have just bought and moved into mine which has a squirrel morso. It is a bit rusty with worst corrosion where flu joins top of stove from water coming in from corrosion of the plate where you attach chimney . I started cleaning back rust today and have some questions:

The collar has split where flu meets fire. I guess this needs replacing? 

There is also a thin crack on the top right hand edge of the stove at back which I have just noticed. Do I need to replace the top plate?

The stove has a back boiler and there is an arm (sorry I don't know the right terminology) which leads to a hole about 1.5 inch diameter. The metal cover is not attached so you can move the arm and expose the hole. Is this normal or should it be sealed with fire cement. Sorry if these are stupid questions. 

I am also thinking of taking of back boiler as having pump on is annoying and stove heat would be enough with ecofan. I also want to install an instant water heater as a back up. 

Any thoughts on this plan also welcome.  

Thank you, Katherine 

[rusty69]

Probably worth replacing the collar. 

 

Does the top plate leak when the stove is alight, does the crack go all the way through? You may get away with it if both answers are no, but be aware of the carbon monoxide risk. A new top plate can be purchased and fitted, which is obviously the best course of action to take. 

 

The flap controlled by the lever is the airwash system for the glass,and should move freely to cover and uncover the hole as required. 

 

If you do remove the backboiler you should ideally  add a firebrick and baffle plate  and must block up the holes somehow where the pipes connect. 

 

A properly designed system running only a couple of radiators shouldn't  need a pump anyway. 

You will also have to address the cause of the leak, whether it be leaking between deck collar and flue, or the flue corroded through at the top 

 

Edited May 12, 2017 by rusty69

[Neil2]

You don't want to take chances with a sf stove on a boat so if the damage allows fumes to escape you will need to replace the damaged parts.

Morso recommend having the weight of the flue supported ie not bearing down on the top plate, but most seem to ignore this and it's often what causes the cracking.

That hole at the back is actually the top air vent air comes in the back and circulates down the front of the firebox.  The lever should be connected to a control at the front/underneath and moves left/right.

A Squirrel stove on its own ought to be more than enough for most narrowboats.   

[Ex Brummie]

Make sure the stove pipe is not 'welded' to the collar through corrosion. This inhibits the facility for expansion when the stove heats up and cracks the top plate. You may be able to repair the top plate with welding, but special rods for cast iron are needed.

[bizzard]

The flue pipe is too closer fit in the collar. If you fill the gap with fire cement it is bound to crack the collar after a time, fill it with a bit of fireproof string and silicone which remains a bit soft and flexible. Ideally a 1/4'' gap at least all around is better.

[KEWalker]

Hi Every one thank so for your replies. That's helpful to know that sealant and sstrongIis best way to fit new flu collar.

I don't think the crack goes all the way through into the stove but it is on the seam so I think it's a risk for leakage if not now then sometime and i will replace top plate and flu  . The back boiler system goes mad if you don't put the pump on when stove hot,  expansion tank overflows and lots of noise . It's not a gravity fed system and it feeds 3 radiators. Does it have to be drained down to remove back boiler? 

[wonderdust]

Can you fit a pipe stat?

[rusty69]

4 minutes ago, KEWalker said:

The back boiler system goes mad if you don't put the pump on when stove hot,  expansion tank overflows and lots of noise . It's not a gravity fed system and it feeds 3 radiators. Does it have to be drained down to remove back boiler? 

The morso squirrel on our boat has three radiators and no pump and a 40 foot pipe run. It would probably work better with only two radiators, but the point is there should be no need for a pump if the system is installed correctly. 

Yes you will need to drain the system to remove the boiler, unless it has isolation valves (unlikely) 

[KEWalker]

Oh okay.  I've read loads of differentthings re. Back boiler systems and they seemed to split into 2 categories pump and gravity. Anyway it would be great if it could be redesigned to work without pump. Will see if I can find a plumber who can help. If not will remove boiler. 

I can't fit a pipe for a while but not using stove until I'm sure it's all sorted. It's mostly warm enough at the moment... luckily. 

[Billy Boy]

Pump feed is fine as long as you remember to switch pump on. Your right about lots of noise though when back boiler boils. 

[rusty69]

58 minutes ago, KEWalker said:

Oh okay.  I've read loads of differentthings re. Back boiler systems and they seemed to split into 2 categories pump and gravity. Anyway it would be great if it could be redesigned to work without pump. Will see if I can find a plumber who can help. If not will remove boiler. 

I can't fit a pipe for a while but not using stove until I'm sure it's all sorted. It's mostly warm enough at the moment... luckily. 

As you have read up on it, you probably know more than me.

 

As i understand it you must have large bore pipes (28mm plus) that increase in height away from the boiler and minimise any restrictions at rads etc. 

 

If your system already has the components, it would be a shame to rip them out imo. You don't say how long your boat is, but rads will distribute the heat better than a fan. 

 

If you do remove the boiler, i may be interested in buying it. 

Edited May 12, 2017 by rusty69

[bizzard]

And ideally the stove with back boiler needs to be at the stern end of the boat for best gravity circulation. Hot water travels much easier uphill than downhill.

[Sir Nibble]

I had a crack in the top of my squirrel like that, so I bought a new top. I found the fixing screws and chain drilled around them from above so as to be able to access the corroded bolts with the top off. as the job proceeded more and more damage became evident. I ended up removing and refurbing the whole stove with in addition to the new top, a new back and grate retainers, an engineering repair to the front, huge amounts of elbow grease de rusting, new rope throughout and stainless fasteners. I would suggest that it's either useable as it is or you are onto a big job.

[KEWalker]

Thanks everyone. Yes I think you're right it's going to be a similar situation to you sir nib. Think I might use it if I'm desperate and save up for a replacement!  

[BEngo]

The stove top crack is a probable BSS failure.

Spare parts are available from Hurworth ( oilstoves.co.uk I think).  Don't buy anything until you have taken the whole stove to bits and checked everything.  Snibble 's experience is typical.

The best way to dismantle it is to put an angle grinder on the bolt heads that hold it together.  4 are into  the top plate from below and 4 are into the bottom plate from above. They go through lugs on the back and front.  The back and front then hold the sides in place. You will need to remove the firebricks and the grate as far as paracticable then bring the boiler into the fire box to get at the top ones.  After that take the top off, ( put a strap round the box to hold it in shape), the boiler out  and remove the rest of the grate.  Then  you can get at the bottom ones.  The heat from the grinder usually allows the remains of the bolts to be screwed out with Mole grips.  If not it is a drill and tap job.

I find the best clean-up toll to be a needle gun, except for the boiler which may be glass lined.  The stainless boilers  can be needle gunned tho.

You will need a lot of 7mm stove rope and some glue to re-assemble it!  Instead of the crap bolts that hold it together use A2 or A4 stainless socket  caphead screws put in with copper grease so you can get them out in future.  Don't overtighten as the various bits of the stove need to be able to move as it expands and contracts.

 

The plate on an arm over the hole appears to be an additional air inlet.  It should not be needed if the door spin wheels are free so ensure they are and then cover it up permanently.

Your experience with the pump off is the water boiling in the back boiler.  To stop this you need the whole of the heating apart from the pipes directly to the radiators to be in 28mm pipe, with a rise from the stove to the far end of the circuit and a fall from the rads to the stove,  and for the radiators to be able to radiate about 8 kW altogether.

Many people put a thermostat on the outlet pipe from the boiler which switches the pump ON when the water is hot enough ( about 50 C seems to work for me).  This minimises noise and battery consumption. 

 

N

[rusty69]

7 minutes ago, BEngo said:

The plate on an arm over the hole appears to be an additional air inlet.  It should not be needed if the door spin wheels are free so ensure they are and then cover it up permanently.

 

Why cover it permanently? Its a useful feature on the stove. 

[BEngo]

Because it is a non-standard fitting  and should cause a BSS fail IIRC.  It is also ideally placed to fill the cabin with CO if the flue is in a downdraft or get cold so that the gas path into the boat is easier than up the flue.

N

[rusty69]

26 minutes ago, BEngo said:

Because it is a non-standard fitting  and should cause a BSS fail IIRC.  It is also ideally placed to fill the cabin with CO if the flue is in a downdraft or get cold so that the gas path into the boat is easier than up the flue.

N

Thanks. Will have to investigate further as we have one on our squirrel. Although im sure the hole feeds into a duct directed at the glass so can't t see it easily being affected by a downdraft particularly if a backboiler or baffle plate are fitted. 

Edited May 13, 2017 by rusty69