Multifuel Stove

Ronnie22_2

Afternoon to you all, I am a new member to the forum and would be grateful of your comments on the following:

I have a 1-5Kw output multifuel stove I want to fit in my house to an existing chimney.

The stove has a 4" outet, which I understand has to be increased to 6" above the register plate.

I'm looking to use 904/904 flexiflue liner with suspended cowl and vermiculite insulation, and due to the fact wood only could be burnt in the stove and Building Doc J Recommendations, I understand I need to increase the size of flue liner to 6".

The stovepipe length will be 750mm and the flexiflue length will be 8.5m.

I intend to fit a 4" to 5" increaser directly on the stove, then a 750mm 5" stovepipe that will connect to a 5" stovepipe to 6" flexiflue increaser.

However, I understand this may be too big an increase size for a good draw.

And, I think is would be sensible to fix the flexiflue liner to the wall just above the register plate to enusre no movement in the liner occurs due to constant heating and cooling of the long run of flexiflue.

Any comments welcome please...

Man_Overboard_2

Clearly, you are well-informed about building regulations, and it would be nice to think that any properly installed stove will be problem-free so long as it conforms to the regulations.

Have you checked the viability of the existing flue? In older properties, it is not unknown for a previous owner to have dismantled the chimney stack because of it's poor condition. I have known of professional stove installers who have failed to make such a basic check.

Ronnie22_2

Thanks for your comments...

I've have visually checked the existing masonary flue/chimney, swept the existing 9" square chimney, it is in relatively good order, however, I don't trust the mortar along its whole length for it to be suitably sealed and not leak into our house/loft space or next door's house, so I intend to line it to be sure.

Open chimney smoke pelleting indicates the flaunching needs a bit of repair, which I will do. I haven't closed the chimney and pelleted it, my pellets are too big, I'd fill the house with smoke. However, the initial test shows me it's suitable for lining. I will do a closed test when I get some smaller pellets just to double check and fill any holes as necessary, if only to stop the vermiculite escaping.

Its that increase of a 4" outlet at the stove to 6" above the register plate and a 8.5m flue liner that concerns me a bit.

But, I expect the vermiculite insulation will assist the draw and longer term health of the liner.

Man_Overboard_2

The mixture of metric and imperial seems unnecessarily confusing, especially coming from someone as well-informed as yourself.

What makes you think that a 50% increase in flue diameter above the register plate will make any difference to the strength of the draw? If you were to use no liner at all, the increase would be even greater. But if you feel that a liner is necessary, then a register plate is completely redundant.

Are you worried that 8.5m is too short, or too long?

muckybutt

Man_Overboard wrote: »

But if you feel that a liner is necessary, then a register plate is completely redundant.

NO ITS NOT !!! :mad:

Ronnie22 YOU NEED to fit a register plate - even if the stove has a liner, if you dont believe me then ask any professional stove fitter - you will get the same answer. For some reason man overboard thinks he knows otherwise - his advice on that matter is wrong.

As for going up from 4" to 6" that isnt a problem, many stoves only have a 4" outlet and going upto a 6" above the reg plate wont make any difference.

Just make sure if coming out the rear of the stove there is a t piece with a soot trap on the bottom, then on the upright section ensure there is a maintenance access point for sweeping.

Man_Overboard_2

muckybutt wrote: »

Ronnie22 YOU NEED to fit a register plate - even if the stove has a liner

Why?

(please stop shouting)

muckybutt

!!!!!! it has been explained to you before in a different thread so I aint going over it again, no register plate and it wont get signed off - simple.

You clearly dont know what you are talking about re stove installs so please dont post incorrect information, the op came here for advice, you gave incorrect advice AGAIN ! op now has the correct advice end of.

Williwoodburner

If you don't fit a register plate, heat will rise up into the chimney cavity, the plate creates a barrier so the heat flows out into the room. :money:

Man_Overboard_2

Williwoodburner wrote: »

If you don't fit a register plate, heat will rise up into the chimney cavity, the plate creates a barrier so the heat flows out into the room. :money:

Yes, but if the stove has a flue liner attached to it's output, then the amount of heat which escapes into the chimney cavity will be minimal once the chimney cavity has itself warmed up.

Building Regulations are concened with safety, not efficiency or cost effectiveness.

Williwoodburner

Man_Overboard wrote: »

Yes, but if the stove has a flue liner attached to it's output, then the amount of heat which escapes into the chimney cavity will be minimal once the chimney cavity has itself warmed up.

Building Regulations are concened with safety, not efficiency or cost effectiveness.

I'm not going to get into an argument with you (you seem to be good at that from other stuff I have read on here) people will read and make up their own minds.

:money:

regards

Willie.

Greenfires

muckybutt wrote: »

!!!!!! it has been explained to you before in a different thread so I aint going over it again, no register plate and it wont get signed off - simple.

You clearly dont know what you are talking about re stove installs so please dont post incorrect information, the op came here for advice, you gave incorrect advice AGAIN ! op now has the correct advice end of.

Seconded. I'm not sure why we have to keep going through this nonsense every time someone mentions installing a stove.