Stove to chimney: 2 x 45 bends, or T-pipe?

40701085

I'm a tad confused over the connection I should be making from my rear (unfortunately it has to be rear) stove outlet to the chimney...

Some advice suggests using 2 x 45 deg bends as this provides less horizontal travel, but does this pose a problem for chimney cleaning and rund the risk of creosote build-up at the joints?

Other advice says use a T-pipe, i.e. with a sump at the bottom to collect creosote deposits & prevent blockage. Yet this means a horizontal run from the stove outlet, & even if it's just the 150mm does this mean its not as effective as the rising 45 deg bends?

Sorry if its a bit long-winded, just want to get it done right.

Thanks

ttm

40701085 wrote: »

I'm a tad confused over the connection I should be making from my rear (unfortunately it has to be rear) stove outlet to the chimney...

Some advice suggests using 2 x 45 deg bends as this provides less horizontal travel, but does this pose a problem for chimney cleaning and rund the risk of creosote build-up at the joints?

Other advice says use a T-pipe, i.e. with a sump at the bottom to collect creosote deposits & prevent blockage. Yet this means a horizontal run from the stove outlet, & even if it's just the 150mm does this mean its not as effective as the rising 45 deg bends?

Sorry if its a bit long-winded, just want to get it done right.

Thanks

I'll reply as I'm sure it will spur sooty_soup and PeteHeat into saying something

From the point of view of the draw on the fire you won't be able to tell the difference between a right angle bend and 2 45 deg bends once you have a fire going. A horizontal section can hold a cold spot and prevent a cold chimney from drawing to start with.

The issue is that a soot fall could block a rt angle bend so two 45's are viewed as being the correct method.

It also depends how you intend to sweep the chimney, with 2 45's you should be able to sweep from the from the fire itself (maybe with a baffle removed first) up the chimney. With a 90 T you will have the problem of sweeping the horizontal section even if sweeping the chimney is easier.

I have a 2ft long horizontal section on the back of an old Stanley 104 MII and I sweep buy taking the whole stove away and removing the horizontal section at least twice a year as thats easier for me than messing with access plates, T's and 45's, but thats not the way your supposed to do it.

Perhaps you could cover all the angles (pun not originally intended) with somthing like a
125mm (5") x 45 Degree Tee with Cap at the base of the chimney then a 125mm (5") x 45 Degree Bend Matt Black Flue Pipe just before the stove itself (links to a page with both items and please don't think I'm saying 125mm if the correct diameter for your stove as I'm just trying to illustrate the type of fittings). But there are other ways as I hope we will soon read?

40701085

Thanks for that ttm,

The 45 deg T with cap plus the 45 bend looks like it could be a go'er.

Sounds like removing the stove when cleaning might be the way forward for me too, the stoves I've looked at seem to have baffle plates/airwash plates that are difficult to remove or get in behind, so in my case you'd have to sweep from the top of the chimney down & then (awkwardly)hoover out the stove.
How is the bend/pipe typically jointed to the stove?

ttm

Typically the pipes are no more than a push fit with a couple of screws to hold then flanges in place. I never even bother to use any form of mastic or sealer, guess I should (dons stainless steel tin helmet) but if the chimney is working OK and the pipe joints are physically good the chimney at worst pulls air in through the gap rather than letting out smoke.

I actually just don't believe some people ever do properly sweep the chimney once a woodburner/multifuel stove is installed as I've come across a lot of setups that really need the stove moving out the way to sweep the chimney which I know will never get done. I suggested taking out a baffle to get access to the flue but again there are stoves where that isn't possible and when the stove is also plumbed into the water/central heating I know they never get moved. So you can see why I think its a good idea to think about the sweeping side before you install the stove in the first place.