Diy Wood Heater

hey guys and guys, i am a noob when it comes to wood heaters and flues. i am a roof plumber by trade and have had a little portable pigtail wood heater for camping which i installed in my rental with downpipe out the back garage door and it worked a treat. now im in my own home and have made my own vertical heater with an old hot water storage cylinder and using 90mm round downpipe that is roughly 4m above the top of the heater. when i start my fire and when i have the main door open it all wants to come out of the main door, i ended up drilling 4 holes above and below my grate with no results except in the picture attatched it wants to come out the holes. i have a diy downdraft diverter in between top of heater and bottom of flue, it is very ashy and when i open the main door it comes out.

The other 2 things i havent tried.....inside originaly it had an 80mm tube all the way through, i used a grinder to cut both bottom and top inside of it but i could only get it with about 150mm left internally just below the flue, the other being i havent tried a bigger flue. trying to avoid purchasing anything if possible. to note i also dont have a cowl on it currently. i understand its too close to the brick wall, i also dont have a ceiling flange yet as i want to move it once i get it right. my thoughts are all leading to a bigger flue, the main door is 350mm wide and 250mm high. the lower ash door is 200mm wiode and 150mm tall. the grate sits about 50mm above the top of the ash door, there is about 450mm - 500mm above the main door. maybe these proportions could be wrong.

any help would mean the world. im just about fed up and gonna go buy a coonara.
cheers, scotty.

Hi Scott;   Welcome to Permies!
I see your problem Scott.
90mm is less than 4" that is just not big enough for a wood fire.  Think 150mm minimum.
Your barrel looks like it was  originally a water heater, they use propane and a 90mm flue is plenty.
Coal burners can use a 90mm pipe.
A wood burner as large as yours needs 150mm or more.

As far as the brick wall behind your stove.  If it is an inside wall no problems as long as it has no wood structure behind it.
If it is an outside wall I would put a lite metal shield between the stove and wall to keep from heating the outdoors.

Sometimes placing a hinged plate at the top of your door will help keep your smoke inside rather than venting to the room.
Oh and patch over your holes you drilled they are not helping.

Hey Scott;  Why not pop on over to the rocket mass heater forum.
You might be intrigued by them.
They are way cool, use significantly less wood and when properly built have very low if any harmful emissions.
A batchbox style can be as small as 90mm , although 150mm is a more common  build.

Check out this thread on a small build in England.
Its a long post but well worth checking out.
https://permies.com/t/43809/Masonry-stove-diy-build-feasible

Hey Scott, neat build!
So, how are downpipes constructed?
When I look online, the downpipes are like our downspouts, for gutters, except ours are usually rectangular in cross section.
Your round downpipes resembles the stuff we use here for heating and cooling ducts.
That stuff starts as flat sheets with pressed edges that hook together.
If your downpipes are like our ducts, two 90mm pipes could be formed into one much bigger duct.
Assuming you have more 90mm down spout laying around, that could allow you to improve the size and performance of your flue, without spending cash.

Beyond that, I second the idea of looking into rocket mass heaters, I think they would serve you well in the long term.