Do we need to seal gas boiler flues, How to correctly seal gas boiler flues, gas safe TB 152

[@sudhiradhikari19]

Thanks for making this video Derek, I hope one day you make video of vertical flue installation, I really want to see the detail of it.

[@rickd6421]

Great video Derek. Never knew the Flue Snug existed until now. If the pre-existing hole is already 152mm wide, i can see their use to save time and make the job look neat, but i wouldn't cut a 152mm hole just to fit one. I'd rather cement the hole. I can see these being reused during boiler replacements where the new flue is a push fit, thereby causing an AR situation

[@kimlaurafowler2066]

Ive had a new flue fitted today. The engineer has left 3 gaping holes. My flue needed an extension as it goes through kitchen then a small room and then outside. I was gutted. I had a decorator here at time. He charged me for filling in the holes. Should the engineer of made it good before leaving?

[@guesser7]

I had a rainwater leak coming into my Worcester boiler. I went out side and peeled back my rubber outer seal to find the installer had used interior silicon sealer to fill the gap round the flue and wall and it had shrunk. Water was running down my gable end and in behind the seal and into the house. I looked at various sealers and opted for a semi-setting rubber gutter sealer that could be applied even in the rain and on wet surfaces and could give me a good weather proof seal between the rubber guard and the roughcast wall. Problem solved. So if you have a drip coming from the bottom of you boiler, check the outer seal.

[@motngaymuahe]

Thank you for your comment. We're having the same issue. I wonder whether you would recommend on what brand of the sealer that you used please?

[@umranhu]

After some advice. Our black rubber fluw seal on outside has failed and split and about to all off ( been on for around 15 years). There is a collar inside and flue is sand/cemented in. Appears the failed part is just to make it look decent. Do i just slide a new 1 over and fix with heat resistant silicone ?

[@BelugaMike]

I really appreciate these types of industry updates.

[@simonmander4314]

Great detailed vid as usual thanks Derek. Would you agree that the picture from the TB (at 03:00 on the video) seems to suggest that sealing with sand and cement from either inside or outside is acceptable?

[@tomkatgastraining]

The best way is sand and cement and like I say in the video if the boiler has a rubber collar on the outside you only need sand and cement on the inside

[@daveysadler3795]

Flue jointing compound is alright?

[@noshah11]

Mu outside flue end the black bit is missing any ideas where I can get the end please thanks

[@rayc1503]

Is it a Worcester Bosch by any chance? If so a complete new flue and and change the external black section. I've seen aleast 3 of these broken. Probably kids kicking footballs against them.

[@noshah11]

@@rayc1503 yes it is

[@rayc1503]

@@noshah11 The black central plume section can be purchased if I remember correctly. If it's the rubber gasket and clamp them you need a replacement flue. Don't disturb the flue itself if at all possible. That's a job for someone who's gas safe registered.

[@markrainford1219]

Off your neighbours boiler flue. It's probably yours anyway.

[@bigfella1952]

Very informative video, covering this very common problem.. What the best thing if the brickwork is in a mess, Rebuild the brickwork and cement the flue into the wall ? Or possibly cement a piece of other pipe in and seal the flue to the wall as it passes through the pipe ? x The Bigfella x

[@shaunny0963]

Some good points. Can you answer this on sealing flue on timber frames using ideal logics plz

[@daveprime1026]

Hi can someone help I have a valiant boiler which is 6 years old I have just had it serviced by British Gas and they have put a danger do not use sticker on it because he said my flue was not cemented in and was dangerous but ask do I want the gas turned off I said no Can some one tell me is this correct and should it need cementing in I have done this just to be safe I have silicone around the flue and a out seal Any help would be appreciated

[@abuadammemon3968]

Nice very info special with reference of TB 152,153 bless 🙏, hope you make more videos on flue .different manufacturers of boiler ,i am sending you pictures how badly installed the flue by kitchen fitters

[@Bladegirlvix]

what can I use to seal gas flue internal on a sloped ceiling?

[@Bradwellify]

Thomas Bradwell Thanks Derek

[@jasonwhittle5008]

Derek can you fit flue jointing compound around flue internally?

[@tomkatgastraining]

I don’t no why you couldn’t

[@rodiBG]

How would you class damage flue terminal?

[@antoniogalluccio4213]

Does fluesnug and pipesnug guarantee the slope downwards and upwards or you need to drill at an angle? I know that using a core drill hole saw at an angle is very hard and plumbers usually to overcome the issu do drill larger diameter holes and then slope the pipes inside? How to do that using this system? And if I already have 4 inch hole to reuse, what can I use to enlarge it to 152mm?

[@tomkatgastraining]

The standard flue in most boilers has the fall built in so you core straight

[@fjrxj1134]

I would also agree with the opinion that external flues should be sealed to prevent water ingress into wall cavities, dampening cavity insulation etc. I have seen weather collars fitted over external flues that hardly cover holes but excepted? If you were to carry out a service or gas check, and you came across a flue sealed with expanding foam, then how could you confirm it's fireproof and the correct material? Sand and cement all the time for me IMHO.

[@mikegallagher2107]

hiya dereck good point but i,ve had an issue on a boundary before document j saying it could not be done but other properties on same street was exactly the same wot is your views on this thanks mike

[@tomkatgastraining]

Follow the building regs and not the neighbours because Sod’s law you will be the one reported

[@mikegallagher2107]

@@tomkatgastraining i did but believe it or not it was let go my point exactly thanks derek

[@prolag9181]

Hi Derek, thanks for your videos they are really helpful. What about flues passing through timber framed buildings? I read they need to be lined and sealed?

[@tomkatgastraining]

Yes they do 👍🏻

[@TheDickPuller]

Always a bit confusing on Timber Frame & clarifications would be good👍 125mm Spiral Duct s generally used as the sleeve, but as a sleeve it completely ‘bridges’ the external wall. I’d value your best advice on sealing these sleeves Del, as the flue doesn’t make contact with any part of the structure, only the sleeve.

[@prolag9181]

Thanks Derek, What would you recommend lining it with and sealing? I have a install coming up in January and just wanted some clarification.

[@tomkatgastraining]

@@prolag9181 my best advice would be to contact the boiler manufacturers for advice.

[@prolag9181]

@@tomkatgastraining 👍

[@saltnvinni1]

Hi Derek, Top video again. What can be done if you are installing a boiler in a 3rd floor flat or above and you can’t seal the boiler from outside or are struggling to get the collar on?? Thank you.

[@tomkatgastraining]

Worcester brought out their rubber seal because of this problem

[@davidjohn3413]

Can you sand and cement outside behind the weather seal then foam inside?

[@tomkatgastraining]

Depends on the boiler manufacturers but why not just use sand and cement inside too

[@davidjohn3413]

@@tomkatgastraining ideal world yes or can request plumbers to do it in there price. I'm a site manager and we generally foam and fill

[@stefanmarianmarin7024]

Thank you for all you do for us, Merry Christmas!!!

[@kyle6656]

In regards to classification as AR, if a boiler is sealed on the inside but externally there is no rubber collar and/ or you are unable to fully inspect the flue visually externally (high level flat) to confirm its fully been sealed with sand and cement externally, would this be deemed AR?

[@tomkatgastraining]

You have to think is it at risk of becoming immediately dangerous. If it is sealed on the inside with no cavity wall and no co on a sweep test then how would this be AR but if it had a cavity wall and POC was going into the cavity that’s a different story.

[@farukadam1696]

Great Derrick Sand and cement is a best Regards Faruk

[@arshadali3286]

Great technical video derek like allways .

[@rayc1503]

Who's coring 152mm hole for a flue snug. As most existing holes are around 120mm. Worcesters use of expanding foam is mainly to aid or expel working at heights. You're required to core 152 hole so the external weatherproof collar can be pushed out from inside the dwelling. In all cases I would still cement screw and fit the internal collar too. Great info Dez, here's to a better 2022 🍻. Onwards and upwards 👍

[@igorchuchro4991]

Mate. You can put the thead through inside of the flue and the hole and pull it in regardless to floor that you're in. There is no need of corring 150mm although I have it in my van just in case lol

[@rayc1503]

@@igorchuchro4991 Ok, so how does the external waterproof collar go on? Can you push it internally through a 120mm core hole?

[@igorchuchro4991]

@@rayc1503 no. You put external collar on the flue. Feed the thread through cored hole and then middle of the flue outside you then pull the cord and flue is landing in the hole.

[@rayc1503]

@@igorchuchro4991 ok cool, I'll try this next time I have restricted outside access 🙏🏼.

[@MrCobraRam]

@@igorchuchro4991 that will only work if fitting a one piece flue, not all will be suitable

[@CommercialGasEngineerVideos]

A very good video topic Derek. Tres bien!!!

[@royboywales]

Just stick to sand and cement, it's cheap 😀 but silicon the flue first. That will take care of any shrinkage probs. Great video though, you are the man 👍

[@brightonuniaccommodationea5968]

Has any one used the “In 2 Out flue seal would this be compliant

[@brightonuniaccommodationea5968]

We need to change a boiler on the 3rd floor and would only be able to cement outside with a Cherry Picker. The quote for this was £500

[@henrybartlett1986]

This is a good one. Many thanks.

[@suheilhanna873]

Very informative, cheers 👍👍

[@monikanader9454]

Useful video, thanks Derek👍👍👍

[@leegudgin2136]

We have to silicone and piece it in

[@themadhatter4761]

Sand/cement every time 👍👍🎄

[@MatthewBester]

Very helpful, thanks.

[@user-te1le7ck6b]

As someome who was told by bg that thier flue wasnt sufficently support despite sand and cement seal , screws amd 1 clip this video just adds tl my argument , bg are adament it needs 2 clips which is fine for belt and braces but stupid to say potentially dangerous given the other fixing points.

[@kevj1964]

Very Informative , cheers TomKat

[@huyongquan6554]

great video again. learn lot. thanks

[@samchappell233]

Top video again 👍

[@traian23us]

I’m gonna start riveting the damn flues from now on 😎

[@garytango]

👍

[@bentzionroyde4786]

Thanks great video 👍

[@igorchuchro4991]

Thanks for the video.:]

[@andymav3023]

Harder to seal outside if your on a high rise block sadly

[@abchannel3737]

Excellent 💐💐💐💐👍👍👍

[@scobeno1911]

What’s your thoughts on using silver tape over the flue joins. I was always led to believe that tape wasn’t aloud as it hides the join so can’t be inspected and may be hiding something. Great vid

[@tomkatgastraining]

The silver tape is not needed unless the boiler manufacturers supply and or spec it.

[@carsonwilliams6319]

👍🏻👏🏻

[@salam238]

Anothe informative video. Thanks

[@MrManj04]

Your a ⭐️

[@SuperWayneyb]

🤘😎🤘

[@openplumbing]

I would alway use sand and cement, certainly not the flue sung, drilling out a bigger hole will make the problem worse

[@TheIcebon]

Keep a bag of ready mix in the van, takes 5 mins and finishes the job better

[@tomkatgastraining]

👍🏻

[@gregoliver240]

Just use sand and cement, then all requirements are covered

[@mustafaakbari6231]

Mustafa akbari

[@shannonj1000]

So you say sand and cement.. on a new build??? Plasterboard wall.. seriously..

[@tomkatgastraining]

Sand and cement are just one of the ways of sealing did you not watch all the video then 🙄