Woodburner filling with water repeatedly

Rek88

Our Woodburner was condemned in October due to rusting a hole in the back as water had some how got in. It’s not really something we noticed so came as a bit of a surprise. Since then the bottom of the Woodburner has been filling with water over a number of days or weeks. We then have to bail out the water. We are assuming it’s rainwater getting in but we don’t get a pattern of heavy rain equals lots of water in the bottom. For example last night storm Isha the thing is bone dry. 

We do have a cowl on the top of the chimney. The chimney is lined but there’s obviously water getting in somehow but we obviously want to rectify this before replacing the Woodburner.

Woodburner was there when we bought the house, so we did not install it. It’s approx 10 years old. The wall behind the Woodburner is now wet too and growing black mold. It’s a disaster and frustrating, will be another couple of months until we can afford to rip it out and replace.

Any suggestions of what is likely happening?

grumbler

Rek88 said:

 The chimney is lined 

Is it a stainless steel flexible liner? If so, I think the only way water can get into the woodburner is through the top end of the liner.
Also, I don't understand why the hole is on the back, not on the bottom of the woodburner. And if it's cast iron it's not that easy to rust through. If it's thin still and the hole is at the back, it possibly burned through.

ThisIsWeird

Hi Rek.

As you suspect, this is surely not from rain coming down the chimney flue - that much rain simply doesn't land in the wee circle of a pot. I know, 'cos I have an open pot and a stove. And, you have a cowl in place...

All I can imagine happening is that there's a leak in the vicinity of the chimney, possible around the outside of the pot, or through a crack in the stack's brickwork, or - more likely - through the flashing where the stack meets the roof. This is clearly a significant amount of water, so is likely focused or collecting somewhere, or is in the path of accumulated water runoff before it then gets in - again, the bottoms of the pots where they are mortared in, or the flashing, which will usually be deflecting away all the accumulated rain that hits the actual stack.

How does it get into the stove? Lawdie knows, but I wouldn't focus on it being the stove's liner that's at fault here; that is more likely simply being breached by water that's coming down around the liner, through the fabric of the stack itself, and then getting through to the stove.

Can you physically move the stove to see behind it?

But, it's recommended-roofer time, I suspect.

ThisIsWeird

I haven't asked - 'cos it's too obvious - but this stove doesn't have a back boiler? No, I won't ask.

Rek88

Just to answer a few questions/comments.

Yes there is a steel flexible liner. No there is no back boiler. Cast iron Woodburner and the hole rusted through is about the size of a golf ball. I imagine with all the standing water in the bottom, it isn’t long before that rusts through too. 

I cant move the stove at the moment to see behind, but can get a pretty good view. The whole wall is wet, not dripping but visibly wet. The exterior of the Woodburner you can see water damage, the collar has some rust where it joins and the feet are starting to rust also.

Great suggestions. It’s a bungalow so getting up there to have a look at the flashing is maybe next. The chimney is on the side of the house. The outside wall of the chimney is dry, there’s no visible water there. 

Maybe I’ll wrap the visible bit of flue in some kitchen roll to see if the outside is getting wet.

ThisIsWeird

Many parts of even 'cast' stoves are made from mild steel, often the back and floor. The only reason they don't rust is that they don't get wet
Get them wet, and they will rust very quickly - it's bare mild steel.
From what you describe, this significant amount of water would seem to be coming down somewhere outside the flue liner. How some of it then makes its way in to the stove is a mystery at the moment, but will actually probably turn out to be not surprising once it's investigated.
I suspect a roofer will find the issue very quickly

Ganga

Rek88 said:

Just to answer a few questions/comments.

Yes there is a steel flexible liner. No there is no back boiler. Cast iron Woodburner and the hole rusted through is about the size of a golf ball. I imagine with all the standing water in the bottom, it isn’t long before that rusts through too. 

I cant move the stove at the moment to see behind, but can get a pretty good view. The whole wall is wet, not dripping but visibly wet. The exterior of the Woodburner you can see water damage, the collar has some rust where it joins and the feet are starting to rust also.

Great suggestions. It’s a bungalow so getting up there to have a look at the flashing is maybe next. The chimney is on the side of the house. The outside wall of the chimney is dry, there’s no visible water there. 

Maybe I’ll wrap the visible bit of flue in some kitchen roll to see if the outside is getting wet.

Is it possible to stuff some kitchen roll up the chimney at the same time to see if it is coming down the flue?

mexican_dave

This thread has been going for a week now. Have you phoned a roofer yet?