HETAS log burner smoking in bedroom

[bernardgreen]

Yes litl I have a thermometer on the flue pipe and things are operating at the correct temperature or sweet spot on the gauge.

What is the temperature on the flue pipe ?

 

[Roger928]

That is not what HETAS told me. HETAS said it is to prevent ( reduce the risk of ) the brickwork of the chimney becoming hot enough to ignite flammable material in contact with the brick work.

Is that the official HETAS stance?
Or just more conflicting info from someone ill informed?
http://www.stovefittersmanual.co.uk/articles/should-i-insulate-my-chimney-flue-liner/

 

[bernardgreen]

Is that the official HETAS stance?

It was the advice given by HETAS when I had my stove and liner installed by a HETAS registered installer. Admittedly my chimney is through a thatched roof so more care is needed, but that said, an un-insulated liner can heat ajacent brick work to a temperature high enough to char timber such as beams supported by that brick work.

Or just more conflicting info from someone ill informed?

Who is the ill informed someone ?

 

[Roger928]

Someone within the hetas group.

 

[lostinthelight]

How much combustion air ventilation is there for the stove?

One would have hoped that HETAS installers would have made sure there was adequate ventilation relevant to the size of stove being fitted?
litl

 

[Steelmasons]

I wrote ""gases going into the flue as it all passes through the combustion area.""

To make it clear for you. A log burner draws in air from the room. this passes through the combustion area where some if not all of the 20% volume of oxygen in that air is used in the combustion of the logs. The other 80% of the air ( mostly nitrogen ) pays no major part in the combustion (*) but is heated to a very high temperature before going up the flue. Nothing goes up the flue that has not been through the combustion area. No un-heated gases are drawn into the flue.


(*) some short lived oxides of nitrogen are formed which may affect the combustion process.

Would CO2% have any bearing on appliance efficiency?

 

[bernardgreen]

Would CO2% have any bearing on appliance efficiency?

Yes

 

[Corgigrouch GTi]

It was the advice given by HETAS when I had my stove and liner installed by a HETAS registered installer. Admittedly my chimney is through a thatched roof so more care is needed, but that said, an un-insulated liner can heat ajacent brick work to a temperature high enough to char timber such as beams supported by that brick work.


Who is the ill informed someone ?

Clearly it is you Bernard. You quietly sneaked in the fact that your experience of solid fuel flues is limited to flues used on properties with thatched rooves. The design of such flues are totally different to the requirements of properties with more conventional roof materials. Some insurance companies do wish the flue to be lined and further insulated inside the brick work but since Hetas do not permit the use of flexible liners in the upper section of the chimney where a thatched roof is used, the use of insulating flue jackets is not possible on flexible liners, the upper section must be done in rigid flue sections and then insulated with a jacket but the preferred method from Hetas is to use stainless steel twin wall rigid flue.

 

[Doggit]

So,was Bernards flue installed correctly then. But this does come back to the premise that if there was a brick chimney in the first place, then reusing this should be acceptable, but I can see the advisability of then using a liner to stop the brickwork around the thatch getting too hot.

 

[Corgigrouch GTi]

So,was Bernards flue installed correctly then. But this does come back to the premise that if there was a brick chimney in the first place, then reusing this should be acceptable, but I can see the advisability of then using a liner to stop the brickwork around the thatch getting too hot.

I don't care if Bernard's flue is correctly installed, my name isn't on the ticket... With a thatched roof, even with a brick chimney, the flue must be lined and insulated but this is a unique situation totally different to the OPs issue...

Bernard's poorly informed advice is potentially dangerous, certainly as dangerous as giving advice on DIY gas work. I think that I understand why some of the other professionals get irate with him..

 

[bernardgreen]

this is a unique situation totally different to the OPs issue...

The OP's issue may be tar and other deposits in the bedroom chimney being heated to vapour point when heat from the flue liner heats the bricks separating the two chimneys. Both the OP's situtation and mine relate to the way a log burner flue should be installed.

It is proven that a un-insulated flue liner can make brick work hot enough to ignite thatch on the other side of the brick work, it follows that an un-insulated flue liner can make brick work hot enough to vapourise tar deposits on the other side of the brick work.

certainly as dangerous as giving advice on DIY gas work.

Sometimes when the OP is obviously going to go ahead with DIY gas work giving advice that might reduce the risk of his or her DIY work may be better than giving no advice. The bombastic attitude shown by some of the less than polite "professionals" on this forum is un-likely to deter a person from attempting DIY gas work. A polite explanation of why the work is high risk will be far nore likely to stop the DIY work than being rude to the OP.

I think that I understand why some of the other professionals get irate with him..

It is "professionals" on this forum that get irritated, professionals elsewhere do not seem to be irritated by me.

 

[Steelmasons]

Yes

....you took a while to answer my question......been googling again have we?..

 

[oilman]

One would have hoped that HETAS installers would have made sure there was adequate ventilation relevant to the size of stove being fitted?
litl

The question was "how much combustion air is there?"

"Hope" does not really answer the question, does it?

 

[Corgigrouch GTi]

It is proven that a un-insulated flue liner can make brick work hot enough to ignite thatch on the other side of the brick work, it follows that an un-insulated flue liner can make brick work hot enough to vapourise tar deposits on the other side of the brick work.

It is not proven at all, it is suggested that it may happen under extreme circumstances but in reality doesn't happen but in light of the insurance industries concerns, Hetas have devised a means of ensuring that the highly unlikely never happens. Far more likely is the sparks from the fire/stove exiting the flue and resting on the thatch. There should be no tar in the chimney with the liner in but this is what I have suggested may be happening and the smoke produced entering the neighbouring chimney due to failed feathering

 

[bernardgreen]

It is not proven at all,

Various researchers have proved from forensic examination of fire scenes that many roof fires are started by chimney brick or stone work being above the ignition point of the materials of the roof.

Far more likely is the sparks from the fire/stove exiting the flue

The thatchers who re-thatched my roof have seen several cases of the lower layers of thatch in contact with a brick or stone chimney being scorched but with no sign of fire damage to the surface layer. The majority of thatch fire start in the lower bone dry layers and often smolder for days before flames and noticable smoke appear. As the flue liner was installed as the same time they and the HETAS engineers did compare notes about what causes fires in thatched buildings.