Barometer in the storm

[L Austin France]

We’ve run out of ideas now and the sweep has asked for help from Jotul. I’m getting cold

Yeah but have you actually tried warming the chimney?

yes we have. So has the sweep. The flue gets hot at the base but no one’s been up on the roof - too risky at the moment too see if it’s hot at the top.

How did you/he warm it?
When our kitchen woodie has the same problem I can actually feel the cold air 'falling' down the chimney when the door is open.
A good test would be to use a joss stick/candle/similar & hold it in the woodie with the door open.
Smoke/flame goes up the chimney = OK
Smoke/flame blows out the door = downdraught/cold chimney
Smoke/flame just swirls around = no air circulation either way so chimney possibly blocked

[Headers]

Yeah but have you actually tried warming the chimney?

yes we have. So has the sweep. The flue gets hot at the base but no one’s been up on the roof - too risky at the moment too see if it’s hot at the top.

How did you/he warm it?
When our kitchen woodie has the same problem I can actually feel the cold air 'falling' down the chimney when the door is open.
A good test would be to use a joss stick/candle/similar & hold it in the woodie with the door open.
Smoke/flame goes up the chimney = OK
Smoke/flame blows out the door = downdraught/cold chimney
Smoke/flame just swirls around = no air circulation either way so chimney possibly blocked

we’ve tried the joss stick thing. It just swirls around.
The fire was re rodded yesterday before the sweep did a test burn.
Thankyou for the suggestions.

[L Austin France]

yes we have. So has the sweep. The flue gets hot at the base but no one’s been up on the roof - too risky at the moment too see if it’s hot at the top.

How did you/he warm it?
When our kitchen woodie has the same problem I can actually feel the cold air 'falling' down the chimney when the door is open.
A good test would be to use a joss stick/candle/similar & hold it in the woodie with the door open.
Smoke/flame goes up the chimney = OK
Smoke/flame blows out the door = downdraught/cold chimney
Smoke/flame just swirls around = no air circulation either way so chimney possibly blocked

we’ve tried the joss stick thing. It just swirls around.
The fire was re rodded yesterday before the sweep did a test burn.
Thankyou for the suggestions.

Don't like to be a pedant but could you explain just how you heated the chimney.
Burn test? If I try to light faggots etc in my woodie when chimney cold I smoke the kitchen out. Once the thing has warmed up it 'pulls' like a good'un.
If your fire worked OK after the new cowl installation what you're describing sounds awfully like the problem I get after trying to light the fire once it's been 'out' for a while & chimney cooled down.

[Headers]

The sweep built a fire with his ‘own’ wood then poured a thick liquid fire lighting product. It went up well and the bottom of the flue was too hot to touch but after a lot of smoke and 30 mins it guttered to a halt.

[L Austin France]

The sweep built a fire with his ‘own’ wood then poured a thick liquid fire lighting product. It went up well and the bottom of the flue was too hot to touch but after a lot of smoke and 30 mins it guttered to a halt.

Was the woodie's door open or closed?
Did the smoke come out at the top of the chimney or out the door?
Did the ' thick liquid fire lighting product' smoke when lit?
I'll understand if you're bored with my questions but I'm genuinly interested & trying to help

[Headers]

The sweep built a fire with his ‘own’ wood then poured a thick liquid fire lighting product. It went up well and the bottom of the flue was too hot to touch but after a lot of smoke and 30 mins it guttered to a halt.

Was the woodie's door open or closed?
Did the smoke come out at the top of the chimney or out the door?
Did the ' thick liquid fire lighting product' smoke when lit?
I'll understand if you're bored with my questions but I'm genuinly interested & trying to help

we tried the doors all closed, then open. Smoke everywhere. A small amount of smoke was getting up the pipe. The liquid didn’t smoke.smoke came out where it’s not supposed to and yes we have had all the seals renewed.
They’re coming back in the week to go up on the roof weather permitting. They will also check the intake port on the fire.
Brr brr brr till then.

[L Austin France]

The sweep built a fire with his ‘own’ wood then poured a thick liquid fire lighting product. It went up well and the bottom of the flue was too hot to touch but after a lot of smoke and 30 mins it guttered to a halt.

Was the woodie's door open or closed?
Did the smoke come out at the top of the chimney or out the door?
Did the ' thick liquid fire lighting product' smoke when lit?
I'll understand if you're bored with my questions but I'm genuinly interested & trying to help

we tried the doors all closed, then open. Smoke everywhere. A small amount of smoke was getting up the pipe. T thick liquid fire lighting productsmoke came out where it’s not supposed to and yes we have had all the seals renewed.
They’re coming back in the week to go up on the roof weather permitting. They will also check the intake port on the fire.
Brr brr brr till then.

OK but if the liquid didn’t smoke it was presumably the sweeps wood that did. Did he try liquid only to heat the chimney?
Trying to heat a cold chimney by burning wood which smokes until it starts to vaporise just won't work on a really cold chimney (ask me how I know).
Yes the bottom of the flue might get heated by hot smoke but the density of the smoke will prevent it from rising any further if there is no buoyancy due to cold air still falling down the chimney.
If you say it worked OK after the new cowl was installed & the flue is deffo clear I'm still thinking that it's a very cold flue problem.
My problem flue is a SS liner installed inside a 5m high, mostly exterior, stack made of rendered terre cotta boisseau ( square blocks with a roundish hole) specially made for chimneys. It's a swine when cold & smokes the place out due to cold air falling down it but after much experimenting ( & smokey kitchen) I've got the better of it & now warm it up with a scrunched up bit of petrole soaked kitchen roll if I've any doubt.
Give it a good go with a decent gas torch , not a Mickey Mouse diy job fixed to a little gas canister, & if that doesn't do it I'll have exhausted my suggestions & leave you in peace.

[Polarengineer]

Another thought. Judging by the timing of fitting the flue cap and the first fire afterwards, it is possible that you have a bee colony in there. This happened to me once and as the chimney top was a bit high to get to I lit a roaring fire ( it is an open hearth and not a cast iron wood burner) which brought down a few pots worth of honey and loads of honeycomb. A right mess.

[Headers]

Another thought. Judging by the timing of fitting the flue cap and the first fire afterwards, it is possible that you have a bee colony in there. This happened to me once and as the chimney top was a bit high to get to I lit a roaring fire ( it is an open hearth and not a cast iron wood burner) which brought down a few pots worth of honey and loads of honeycomb. A right mess.

Thankyou for the thought but we have had the flue rodded twice and there is nothing.

[niemeyjt]

Maybe somewhere there is a cold air "feed" into the room - is that somehow blocked by the storm?

Our previous house had a piece of 6" plastic drain pipe built into the floor to the outside to ensure a good airflow.

As for low pressure - how would that stop smoke rising - high pressure is more likely to do so perhaps - air pressure is the downward force of the air. Same reason tides are higher when the pressure is low.