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A flue is a duct, pipe, or opening in a chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors. Historically the term flue meant the chimney itself. In the United States, they are also known as vents for boilers and as breeching for water heaters and modern furnaces. They usually operate by buoyancy, also known as the stack effect, or the combustion products may be 'induced' via a blower. As combustion products contain carbon monoxide and other dangerous compounds, proper 'draft', and admission of replacement air is imperative. Building codes, and other standards, regulate their materials, design, and installation.

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  1. Be kind

    Can my flue be fixed from outside wall

    My boiler flue isn’t angled slightly towards boiler. In case of water. Can this be corrected from the outside of flue?
  2. Be kind

    Renew outside flue terminal

    If I’ve had a whole new flue fitted to my boiler and going outside through wall. Should the engineer fit a new outside terminal as well. Or is this not needed?
  3. dilligaf

    Condition Of Flue For Gas Boiler Help?

    I decided to inspect the inside of my Glow Worm Micron 30FF Flue by using an endoscope. Can anyone tell me how this looks to them, is the condition reasonable on the inner flue piece? Oh and what is that funny shape inside the flue going out towards the outside? Also the last two photo's are...
  4. C

    Gas/Oil Flue Differences?

    Morning, I need to replace my flue as it has suffered some damage from a over enthusiastic digger driver with a rogue bucket 😡 I am a relatively competent diy'er, so thought this would be a doddle... I have a condensing oil boiler with a horizontal flue at 80/125mm. First port of call was...
  5. P

    Boiler flue on Party wall boundary wall

    Im aware of the regulations that say you can not position a flue on a boundary wall if this blows into your neighbours garden, but does this still apply if the flue is situated 3 stories up (i.e. blowing out the gable wall in the attic) Approx 8-9meters high. Would the gasses disperse enough...
  6. I

    Boiler flue blocked?

    Am I right in thinking my ideal logic boiler flue is blocked? It looks like insulation or expanding foam? Please enlighten me and so I know if it needs immediate attention or not. Photo attached? Thanks,
  7. I

    Is my flue installed incorrectly?

    Hi guys and girls. So…. Bought an apartment in a conversion rather than new build. Since buying it I’ve been experiencing headaches, sickness and dizziness. At the time I just thought I was coming down with something but then a TV engineer came to install an aerial in the loft and he showed me...
  8. S

    Thoughts on Internal flues, aesthetics and specifics on flue falls

    HI, Ideal Logic flue fall is 1.5 degree, as per manufacturers instructions. Did you know that they have an allowance? The upper allowance is 2 degree, but this is not in the instructions. The question is if the flue fall is say 1.9 degree, does it comply with the manufacturers instructions...
  9. FKBIH27

    IDEAL - Vertical FLUE

    I have a customer that wants me to fully strip down and service their boiler, I have been round previously for other work I did have a look at their boiler and flue. The flue has caught my attention as there do not seem to be any "ports for flue analyser. it is a vertical flue. i am newly...
  10. M

    Help. Vertical flue adjacent to chimney

    Hello Everyone Recently bereaved friend of mine is wanting to replace his 15 year old Combi. It is in the loft on the party wall of a semi ( pitched roof has three sloping sides). He asked his Gas Safe Service Engineer for a price to replace. Engineer said that existing vertical flue is too...
  11. L

    Extension direction!

    Hi everyone, I was hoping to find a place where I could some advice to what’s hopefully a straightforward question and this looks to be it :) I have an Intergas combi boiler that has a horizontal extension via my outside wall and to the balcony, all in all about 5 meters in length. Due to some...
  12. C

    Flue Integrity Test.

    Hello, I'm after a bit of advice. If you, as a gas engineer, needed to "fault find" on a boiler that has a problem, would you do a flue integrity test as one of the first ports of call. The boiler ignites, stays lit for 20 seconds or so then shuts off. About 20 seconds later, the boiler...
  13. R

    Which Flue gas analyser

    Anyone recommend a flue gas analyser. My old Kane needs a replacement and they all seem to have gone up in price. Someone suggested bluelyzer but I've never heard of them.
  14. L

    Tricky Flue Relocation

    Very recently had a garage side extension on our house and now the boiler flue is too close to the wall. the boiler was fitted about 5 years ago and wasn’t touched when we did the extension. I need to get a plumber to change it but would like to have a plan before they come, can anyone give me...
  15. R

    23 year old Vaillant Thermocompact needs replacing - flue problems?

    We built our detached house 23 yrs ago, having a Vaillant Thermocompact boiler with a Megaflo tank, and it's been excellent. The boiler sits in a room under the stairs, with the flue discharging out of the side wall (no windows or doors) at a height of around 2.5m from the ground. The...
  16. M

    Selling brand new Worcester flue kit

    As new, unopened (ordered in error) Worcester - 80/125mm condensfit telescopic flue kit £110 o.n.o, can post out nationwide no extra cost
  17. C

    Valor Turbochim Side Flue 517SF Wont Start Fan

    Hi All I have a Turbochim side flue fire, installed Dec 2000 and has worked well for 20 years. It would not turn On the other day. Normally you press and hold On button and the fan starts. Now when you press the ON button you here a click and the fan fails to start. The fan has been tested (...
  18. C

    Problem with Valor Ultimate Turbochim Side Flue Fire 517SF

    I have a Turbochim side flue fire, installed Dec 2000 and has worked well for 20 years. It would not turn On the other day. Normally you press and hold On button and the fan starts. Now when you press the ON button you here a click and the fan fails to start. The fan has been tested ( Hereford...
  19. Imdesperatenow

    I need some sort of confirmation

    TIA I have removed the info I now have someone coming to check it
  20. B

    Why would a service engineer drill a hole in flue to check emissions?

    This is the background. I noticed a smell of oil in a small enuite that adjoins my boiler house and went out to boiler house and oil tank to have a look. I could not find any odours of oil anywhere so assumed it had come in window, ie you can get a smell of oil from tank, near the outlet pipe...