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23
Hi,

Looking for advice as noticed today that the rubber collar seal with sits around the flue of my condensing boiler is coming away slightly on the top part from the external brickwork...is this something which needs to be looked at? Think the birds have been pulling at it!
Thanks
 
Any chance of a pic ?
 
Looks ok for now any worse I would recommend a replacement
 
Looks ok for now any worse I would recommend a replacement
Thanks for the reply...the rest looks fine....I'll keep an eye on it...hopefully it will be ok till next boiler service in Feb/March don't want to waste gas engineers time for something trivial
 
Is this something which will need to be fixed immediately? I've read through baxi installation book that came with boiler and can't see any reference to this...is it very important? Thanks all
 
Naaa you would be surprised how many are like that
 
Lots fitted like it but the white part is not ment to be on show and can rust through

Hello scott_d,

What is the situation where this Boiler is fitted and the Flue has to be extended out because of a Balcony above it or something similar - do the Flue extension pieces have a different material for the outer skin ?

The Baxi Multifit Flue accessories range includes an `Under Balcony / Under Eaves` Kit and the Pipe etc. is White.

Chris
 
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Hello scott_d,

What is the situation where this Boiler is fitted and the Flue has to be extended out because of a Balcony above it or something similar - do the Flue extension pieces have a different material for the outer skin ?

Chris
There are a few options available, if you are GSR join the gas safe section
 
The white part appears to be plastic but I can't reach out of window far enough feel it...no signs of rust on it..a bit grubby but we live on a busy road etc...the eaves on our house come out quiet a bit more so than other houses I have noticed.
 
There are a few options available, if you are GSR join the gas safe section

Hello again scott_d,

You are wrong regarding your comment that `No white should be showing` on this Baxi Bolier Flue.

The Baxi Multifit Flue Kits including the `Under Balcony & Under Eaves` kit are all manufactured using the same Metal for the outer skin of the Air Intake.

If an Under Balcony Kit was installed the entire external run would be an exposed White Flue pipe made of the same material as You are stating cannot be exposed.

The only possibly different material for an external section of Flue for these Baxi Boilers is on the `Plume Management` kits.

I am a Gas Safe registered Gas Engineer but I don`t need to join the Gas Safe section of the Forum to be able to contradict your mistake and give You the correct information.

What You have suggested could cause the OP to engage a Gas Safe registered Heating Engineer to alter the Flue on his Boiler - For NO reason.

Chris
 
Hello again scott_d,

You are wrong regarding your comment that `No white should be showing` on this Baxi Bolier Flue.

The Baxi Multifit Flue Kits including the `Under Balcony & Under Eaves` kit are all manufactured using the same Metal for the outer skin of the Air Intake.

If an Under Balcony Kit was installed the entire external run would be an exposed White Flue pipe made of the same material as You are stating cannot be exposed.

The only possibly different material for an external section of Flue for these Baxi Boilers is on the `Plume Management` kits.

I am a Gas Safe registered Gas Engineer but I don`t need to join the Gas Safe section of the Forum to be able to contradict your mistake and give You the correct information.

What You have suggested could cause the OP to engage a Gas Safe registered Heating Engineer to alter the Flue on his Boiler - For NO reason.

Chris
The balcony kit is just the plastic exhaust not the metal air intake?
 
It’s the same issue as ideal have , unless you can prove it’s the multi flue your going on about just cut it back as another engineer will at risk it to cover them selfs. It’s because it’s not uv protected, I would at risk it ! Hope this helps
 
It’s the same issue as ideal have , unless you can prove it’s the multi flue your going on about just cut it back as another engineer will at risk it to cover them selfs. It’s because it’s not uv protected, I would at risk it ! Hope this helps

Won't be ar unless it's showing signs of distress ncs atm
 
The balcony kit is just the plastic exhaust not the metal air intake?


Hello again scott_d,

Sorry for the delay in responding I was having a late Dinner.

Baxi and other Manufacturers Fanned Flue Boiler Flues are now often Plastic for both The Air Intake and for the Exhaust - because of the condensate the Exhaust is not a metal pipe.

Older Baxi Fanned Flues [E.G: Baxi Solo`s] were Metal construction for both the Inner and Outer Pipe - Aluminium or an Aluminium Alloy.

The `Under Balcony & Under Eaves` Kit is just a Plastic Exhaust extension pipe which attaches to the Boiler Flue Terminal - the `normal` Air Intake is fine taking Air from the Terminal position.

The point that I am making is that the `Plastic` Air Intake outer skin of a piece of Baxi Multifit Flue pipe is not going to rust because it is not metal.

Even Boiler Flues that do have a Metal outer skin for the Air Intake are made from Aluminium or an Aluminium Alloy - which again will not rust.

Most Boiler manufacturers have realised that there cannot be a `Rust Risk` on Flue pipes Years ago - otherwise We would be finding loads Boiler Flues where the underneath of the Flue pipe adjacent the wall where drips form was rusted away forming a hole.

We do come across this sometimes on the less well known brands of Boilers / Boiler Flues where the Manufacturers have used a somewhat `Inferior` metal material or jointing system - but I have not found it on any of the `Main Brands` of Boilers for many years.

Member Jay Jay states that the Plastic outer skin should not be exposed because it is `Not UV protected`.

I would dispute that on the basis that a `Plastic` material does not have to be outside of a building to suffer `UV degradation`.

IF the Plastic outer skin of the Boiler Flue was susceptible to UV Degradation it would not be suitable to be installed in any position where Sunlight / UV rays could fall on it.

I have seen many examples of `UV Degradation` happening inside a Building - including in my own Home:

I have 3 TRV`s on my Heating system where the Heads have discoloured / faded from UV rays - they not in `direct sunlight` but the Sun / UV rays do shine upon them for a period of each day.

When I was doing some refurbishment works to my Home there was a period of time when I had taken down the walls and door to my Cylinder cupboard this exposed the Hot Water Cylinder spray on insulation foam to Sunlight from a Hall window for a period of about 7 months [I had a delay on the Building works] - the UV rays degraded the foam insulation as it was never designed to have Sunlight / UV rays shining upon it.

IF the Baxi / any Manufacturers Flue pipe outer `Plastic` skin was NOT supposed to be exposed to UV rays the Flues could not be fitted anywhere where Sunlight / UV rays could be shining upon the pipe or it would be susceptible to `UV Degradation` just as in the examples that I described above.

Although we might `know` that UV rays are stronger outside a Building they are still able to degrade Plastics and other materials inside a Building as I described above.

Chris
 
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Hello again scott_d,

Sorry for the delay in responding I was having a late Dinner.

It is the other way round on Fanned Flue Boiler Flues - the `Outer` Air Intake is some form of `Plastic` material and the Exhaust is Metal - usually Aluminium or an Aluminium Alloy.

The `Under Balcony & Under Eaves` Kit is just the Metal Exhaust extension pipe which attaches to the Boiler Flue Terminal - the `normal` Air Intake is fine taking Air from the Terminal position.

According to your theory that Metal Combustion Products Exhaust pipe should not be exposed to the elements.

The point that I am making is that the `Plastic` Air Intake outer skin of a piece of Baxi Multifit Flue pipe is not going to rust because it is not metal.

Even Boiler Flues that do have a Metal outer skin for the Air Intake are made from Aluminium or an Aluminium Alloy - which again will not rust.

Most Boiler manufacturers have realised that there cannot be a `Rust Risk` on Flue pipes Years ago - otherwise We would be finding loads Boiler Flues where the underneath of the Flue pipe adjacent the wall where drips form was rusted away forming a hole.

We do come across this sometimes on the less well known brands of Boilers / Boiler Flues where the Manufacturers have used a somewhat `Inferior` metal material or jointing system - but I have not found it on any of the `Main Brands` of Boilers for many years.

Member Jay Jay states that the Plastic outer skin should not be exposed because it is `Not UV protected`.

I would dispute that on the basis that a `Plastic` material does not have to be outside of a building to suffer `UV degradation`.

IF the Plastic outer skin of the Boiler Flue was susceptible to UV Degradation it would not be suitable to be installed in any position where Sunlight / UV rays could fall on it.

I have seen many examples of `UV Degradation` happening inside a Building - including in my own Home:

I have 3 TRV`s on my Heating system where the Heads have discoloured / faded from UV rays - they not in `direct sunlight` but the Sun / UV rays do shine upon them for a period of each day.

When I was doing some refurbishment works to my Home there was a period of time when I had taken down the walls and door to my Cylinder cupboard this exposed the Hot Water Cylinder spray on insulation foam to Sunlight from a Hall window for a period of about 7 months [I had a delay on the Building works] - the UV rays degraded the foam insulation as it was never designed to have Sunlight / UV rays shining upon it.

IF the Baxi / any Manufacturers Flue pipe outer `Plastic` skin was NOT supposed to be exposed to UV rays the Flues could not be fitted anywhere where Sunlight / UV rays could be shining upon the pipe or it would be susceptible to `UV Degradation` just as in the examples that I described above.

Although we might `know` that UV rays are stronger outside a Building they are still able to degrade Plastics and other materials inside a Building as I described above.

Chris
On a Vaillant boiler the outer is metal and the inner is plastic.(are you just on about baxi’s?)
 
On a Vaillant boiler the outer is metal and the inner is plastic.(are you just on about baxi’s?)


Hello Harvest Fields,

Yes - Thanks for the correction - I meant to write `Plastic` for the inner and outer pipe - I also noticed another error in my message - I will Edit my post.

Chris
 
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Shaun i would play safe as it needs to be done, the thing is if someone else goes to the job and goes o t t then it’s just aggro you don’t need. I understand what your saying though!
 
Hello Harvest Fields,

Yes - Thanks for the correction - I meant to write `Plastic` for the inner and outer pipe - I also noticed another error in my message - I will Edit my post.

Chris
I am yet to fit a flue with a plastic outer air intake but have heard some are changing to this type.
I have seen plenty of rusted flues on modern boilers, so I wasn't scaremongering.
Especially by the seaside where baxis are incorrectly fitted in new apartment blocks.
Ideal and baxi don't allow white to be on show externally because it's cheap thin metal.
 
I am yet to fit a flue with a plastic outer air intake but have heard some are changing to this type.
I have seen plenty of rusted flues on modern boilers, so I wasn't scaremongering.
Especially by the seaside where baxis are incorrectly fitted in new apartment blocks.
Ideal and baxi don't allow white to be on show externally because it's cheap thin metal.

Viessmann are totally plastic
 
The balcony kit is just the plastic exhaust not the metal air intake?


Hello again scott_d,

Further to your comment quoted above:

I think that I have probably seen more Boiler Flues extended beyond Balcony`s using just the normal twin pipe Flue pipe than I have seen extended with a `Balcony & Eaves` extension kit.

I could be totally wrong about this comment as I have never researched it but I am not sure whether ALL Manufacturers even make a `Balcony & Eaves extension kit` ?

I know that they all manufacture a `Plume Management kit` but do they all make a `Balcony & Eaves extension kit` ?

I also notice that at just 1035mm long excluding the terminal that the Baxi Multiflue Balcony kit would probably not be long enough to extend the Flue correctly for many Balcony`s - and at £110.00 each [inc. vat] I wonder how many Heating Engineers would baulk at buying 2 Kits and install the Flue using just the `normal` Flue pipe and Terminal etc. ?

Perhaps that is why I see so many Flues extended just using normal Flue pipe ?

Going back to our original topic of discussion:

If the White outer skin of the Flue pipe must not be visible / exposed in any way because it is susceptible to rusting one of the MOST important points in the Manufacturers Instructions should be that the back of the Flue Terminal MUST slightly enter the hole in the wall so that when the making good is done NONE of the White outer Flue pipe is outside the hole - not even a couple of millimetres.

If the back of the Flue Terminal was even a couple of millimetres past the making good / mortar etc. that would cause a `ring` of white outer pipe between the wall and the back of the Flue Terminal which would be susceptible to rusting.

The Flue Collar is NOT going to prevent some rain running down the wall and going behind the Collar to get to the point where the Flue pipe exits the wall even though the use of a mastic is usually recommended it does not last for the life of the Boiler so the Collar cannot be relied on to prevent what I described.

I wonder how many Boiler Flues are fitted exactly like that / would fall into that category ?

Chris
 
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Hello again scott_d,

Further to your comment quoted above:

I think that I have probably seen more Boiler Flues extended beyond Balcony`s using just the normal twin pipe Flue pipe than I have seen extended with a `Balcony & Eaves` extension kit.

I could be totally wrong about this comment as I have never researched it but I am not sure whether ALL Manufacturers even make a `Balcony & Eaves extension kit` ?

I know that they all manufacture a `Plume Management kit` but do they all make a `Balcony & Eaves extension kit` ?

I also notice that at just 1035mm long excluding the terminal that the Baxi Multiflue Balcony kit would probably not be long enough to extend the Flue correctly for many Balcony`s - and at £110.00 each [inc. vat] I wonder how many Heating Engineers would baulk at buying 2 Kits and install the Flue using just the `normal` Flue pipe and Terminal etc. ?

Perhaps that is why I see so many Flues extended just using normal Flue pipe ?

Going back to our original topic of discussion:

If the White outer skin of the Flue pipe must not be visible / exposed in any way because it is susceptible to rusting one of the MOST important points in the Manufacturers Instructions should be that the back of the Flue Terminal MUST slightly enter the hole in the wall so that when the making good is done NONE of the White outer Flue pipe is outside the hole - not even a couple of millimetres.

If the back of the Flue Terminal was even a couple of millimetres past the making good / mortar etc. that would cause a `ring` of white outer pipe between the wall and the back of the Flue Terminal which would be susceptible to rusting.

The Flue Collar is NOT going to prevent some rain running down the wall and going behind the Collar to get to the point where the Flue pipe exits the wall even though the use of a mastic is usually recommended it does not last for the life of the Boiler so the Collar cannot be relied on to prevent what I described.

I wonder how many Boiler Flues are fitted exactly like that / would fall into that category ?

Chris
Some manufacturers allow white on show. Vaillant & Worcester for example.
Baxi do not, hence me saying at the start 'is it a baxi' ' no white should be showing' and then you got on your high horse :p

A correctly fitted flue should be cut the the right length, sealed inside and out and a weather collar fitted, or to the manufacturers instruction. I see plenty done properly and plenty of 'that will do'
Always worth spending an extra 30 minutes to do it properly
 
Totally agree mate ideal and baxi are losing on new builds, as Vaillant have there own new build boiler/social housing boiler this allows them a bit of give if required
 
Some manufacturers allow white on show. Vaillant & Worcester for example.
Baxi do not, hence me saying at the start 'is it a baxi' ' no white should be showing' and then you got on your high horse :p

A correctly fitted flue should be cut the the right length, sealed inside and out and a weather collar fitted, or to the manufacturers instruction. I see plenty done properly and plenty of 'that will do'
Always worth spending an extra 30 minutes to do it properly

Hello again scott-d,

I totally agree that a Boiler Flue should be fitted correctly and I would never have any unnecessary Flue pipe protruding out of a wall as in the photo posted by the OP of the Flue that we are `debating` on here.

You correctly stated that the Manufacturers Instructions should be adhered to and that would include dimensions which if followed correctly would result in a correctly installed Flue without any unnecessary / `prohibited` section of Flue pipe protruding past the wall surface.

BUT - If as You state Baxi [and Ideal] verbally specify [?] `No part of the white flue pipe must be showing / exposed` this should also be highlighted in the Flue Installation Instructions because with previously manufactured Boiler Flues made from Aluminium or an Aluminium Alloy Heating Engineers have often given themselves some `leeway` when measuring Flues and allowed for a slight protrusion of the Flue pipe past the wall surface.

There are thousands [perhaps hundreds of thousands ?] of previously installed Boiler Flues where the Flue pipe protrudes perhaps 25mm past the wall surface to the Terminal.

Because of that `Industry Habit` Baxi and Ideal should highlight their very important specification clearly in the Boiler Flue Installation Instructions - NOT just state `Install as per our Instructions & dimensions`.

I have to ask - How did You become aware of what you have stated about Baxi Boiler Flues / `No white Flue pipe must be seen / exposed` because of the `thin metal` outer skin of the Air Intake pipe ?

Chris
 
It’s in the instruction manual with boiler, also when you go on a training course they tell you then
Hope this helps

Hello Jay Jay,

Does it actually specify something like:

`None of the Flue pipe must protrude past the external wall surface` - words to that effect ?

I have already acknowledged that if the Manufacturers Instructions / Dimensions are followed correctly there should not be any Flue pipe protruding past the external wall surface but because of the `Industry Habit` that I previously described is the above actually specified in writing ?

I have never seen that specified in writing in the Manufacturers Boiler Instructions or in any Flue Kit Installation Instructions.

Chris
 

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