Inert Stove - question on flue

johnstown

Folks,

I have an multi fuel inset stove to be installed in an old fireplace
on a gable end wall.

I took out the old fireplace.

When I bought the stove, it was supplied with a spigot, 1/4 metre of 2
mm heavy pipe and 10 metres of 316 double skin piping.

Before getting the stove installed, I have to do a lot remedial work
with the hearth, back of fire etc.

The 1/4 metre of pipe fits in vertically into the stove.

I am a little perplexed as to how the 1/4 of pipe will work with the
fireplace lentil.

There is a band around the front of the stove. The distance between
the front of the spigot and this band is about 5 inches. The lentil
over the fireplace opening is 4.5 inches thick. I will be adding a
marble insert surround around the stove and this will add another few
inches.

Thus I cannot figure out how the 1/4 metre of solid pipe will work
with the lentil.

See attached pictures of fireplace and stove.

You will note that the stove with spigot and 1/4 m of solid pipe is
30.5 inches high.

I am considering taking out the lower lentil in the fireplace and
putting a new one a little higher up.

However, the distance between the front surround/band on the stove and
the spigot is about 5 inches. When marble and filling is added to the
front of the stove, this will add another 2.5 inches. This means the
1st 1/4 of solid pipe coming out of the spigot will not be going back
far enough into the fireplace.

I rang the stove place as I assumed that the 1/4 metre solid pipe
would have to be changed to be angled. The installer at the stove
shop said no, that the 1/4 would have to be used and to kango a
channel up in the fireplace.

Anyone got any ideas?

PS I know the wooden surround is a potential fire hazard.

North West

Hi Johnstown
See attached
NW

johnstown

Thanks for the response Northwest.

At this stage I took out the old lentil and put a new one in a bit higher up.

I also got rid of the straight 1/4 pipe and got two 45 bends. The stove fits in perfectly now. I did not actually install the stove yet.

I then put a sheet of vermiculite board behind where the stove would be installed and also another two boards to sides. I infilled between the vermiculite boards and the original part of the fireplace with vermiculite cement.

Finally, I plastered the front of the fireplace with a sand/cement/lime mix (2:1:1 ratio).

Tomorrow the new hearth is being installed.

After that, I have a new marble surround coming which will surround the stove.

See attached pictures.

I have a few additional questions:

a) I attached the spigot to the stove by just bolting it to the stove using the bolts supplied. It seems to sit fairly well. I assume I do not need to seal this with fire gasket or something?

b) The stove will have to be installed at the same time as the marble insert. This is where I am a bit lost again. We are hoping to leave the timber surround/mantle in situ and not have to move it.

I assume that I will need to feed the flexi flue up the chimney first, then attach it to the two 45 bends which in turn are attached to the spigot. I am assuming the stove will need to sit out a little on the hearth (all joined up the bends, flexi flu etc. Then I assume it’s a case of slipping the marble insert behind the stove and pushing the two into place. After that I just need to infill with vermiculite from the top of the chimney so that the entire flexi flu is surrounded by vermiculite.

I also assume when joining the bends together, I can just use a little cup head bolt (cup side on the inside). When joining the 45 bends to the flexi flu, do I need some kind of adapter? Again, do I need to fix in place using cup head bolts? Is fire gasket required for joining these?

When joining the 1st 45 to the spigot, the only way it will fit is to put the smaller end in. How is this to be held in place as there is no hole in the spigot to facilitate a bolt?

Sorry for all the questions.

johnstown

Ignore the cement block and timbers between the vermiculite boards in the attached. They are just holding the vermiculite boards in place until the vermiculite cement sets behind them.

North West

Hi Johnstown
Looking well. You can buy mastic type fire cement in any builders merchants. Make sure you put on 45 deg bends and any joints that you encounter. There is a chimney fixing for final installation of flexible flue. its like a clamp to hold the flue at top of original flue. Check where you buy the flexible flue about fixing it to bend, you may need some type of collar/ clamp. make sure you seal where all joints are. Good to see it working out for you.
NW

North West

More information attached
These products are available at most merchants
NW

johnstown

Thanks again North West.

Do I just connect the stove to the 45 bend and flexi flu and leave the stove out a bit and then slip the granite surround (originally I was going with marble but changed my mind) in behind it and then push the stove into place?

Someone mentioned to me that I can just put the granite surround in, then slide the stove in and then connect the bend into the spigot from within the stove. I cannot see how I would seal adequately between the spigot and the 45 bend then. I suppose I might be able to get a bit of that fire cement up there.

North West

Hi johnstown
Put the flexible flue down chimney. Connect the 2 bends together and fix the flexible flue. Leave enough length after connecting bends and flue to do the back. Then fix the bend to the collet on stove and seal. You will need someone on top of chimney to pull flue pipe up as and anchor someway at top of chimney. you push in the stove to final position in fireplace. Seal around flue and flexible flue over stove. Fill the cavity between flue and flexible flue with vermiculite from roof and seal around the top of chimney at the exit on flue. Job done Dont forget to get a cowl for top of flexible flue.
Hope all is going well.
NW

johnstown

North West wrote: »

Hi johnstown
Put the flexible flue down chimney. Connect the 2 bends together and fix the flexible flue. Leave enough length after connecting bends and flue to do the back. Then fix the bend to the collet on stove and seal. You will need someone on top of chimney to pull flue pipe up as and anchor someway at top of chimney. you push in the stove to final position in fireplace. Seal around flue and flexible flue over stove. Fill the cavity between flue and flexible flue with vermiculite from roof and seal around the top of chimney at the exit on flue. Job done Dont forget to get a cowl for top of flexible flue.
Hope all is going well.
NW

Hi Nw, thanks stove installed ok for a finish.... Working fine now although not as warm as I expected. There is more heat from the stovax rival 55 we put in a few years ago although it is a bigger machine and is not on a gable end wall....

Thanks

johnstown

North West wrote: »

Hi johnstown
Put the flexible flue down chimney. Connect the 2 bends together and fix the flexible flue. Leave enough length after connecting bends and flue to do the back. Then fix the bend to the collet on stove and seal. You will need someone on top of chimney to pull flue pipe up as and anchor someway at top of chimney. you push in the stove to final position in fireplace. Seal around flue and flexible flue over stove. Fill the cavity between flue and flexible flue with vermiculite from roof and seal around the top of chimney at the exit on flue. Job done Dont forget to get a cowl for top of flexible flue.
Hope all is going well.
NW

Hi Nw, thanks stove installed ok for a finish.... Working fine now although not as warm as I expected. There is more heat from the stovax rival 55 we put in a few years ago although it is a bigger machine and is not on a gable end wall....

Thanks

johnstown

Hi,
I installed a Nestor Martin IN13 (5KW) before Christmas in a gable end wall.
Initially the stove threw out very little heat and the room. It has improved a bit but is still bad. I have a thermometer in the room and if I have the stove on for say a couple of days non stop, using well seasoned hardwood, the temperature in the room does get up to 21C. I have been adjusting the controls as per the instruction manual.
According to room calculators I am using, 5KW should suffice for the room size.
I am familiar with using an inset stove and have a Stovax in another room which gives out great heat.
Anyhow, the IN13 was a self install. Before the stove was installed, I lined the and sides of where the stove would sit with vermiculite boards. The stove was then installed along with a double skin chimney liner and backfilled the entire chimney with loose vermiculite.
When the stove has a good fire, I reckon there should be more heat coming from it. I can get up to 21C on wood (after many hours of firing). I would get more from coal.
I reckon that an open fire would be better. Strange thing is, if the door of the stove is left completely open, then the heat output is far superior (goes from 21C up to 25C).
I am wondering if something is wrong inside the stove. See attached pictures from inside the stove. There is a vermiculite board that sits over the fire inside, which I have removed to show a kind of flap (stainleess steel originally) which I am wondering if I have installed it correctly. The vermiculite board was only removed for the purposes of taking the picutre.
Would anyone have any comments?

Thanks