My Baxi has been regularly serviced for 15 yrs and had no problems with it's installation or air supply vent. Last year NPower serviced it....no problems. This year a different NPower guy has said it is not installed correctly and should be sealed in the opening with tin sheet? He also said the vent from under the wooden floor is no good because he can't certify there is good ventilation under the floor? He has declared it as "at risk". Any ideas people?
Baxi bermuda back boiler
- Thread starter Harrigate
- Start date
There should be a plate sealing the chimney around the flue just above the back boiler. Is there a hatch anywhere so he can see under the floor regarding ventilation? You'll probably find you have air bricks or vents outside providing a pathway for ventilation under the floor and coming through the room via the combustion vent. Unless the vents or air bricks outside are blocked its unlikely that it will be at risk. Sounds like someone is being lazy and not properly checking. Might be worthwhile getting them back out incase there's any clauses regarding repairs not being covered due to an unsafe situation.
I pointed out to the Serviceman that there were multiple airbricks on all 4 walls of the bungalow but he said he couldn't verify that airflow was adequate. I then pointed out that the bungalow was built in 1973 and that without adequate airflow the wooden floors would have rotted and caved in by now but he didn't even blink.
Was it part of installation regulations to seal the chimney back in the mid 90s? And if not are we all expected to bring our boilers installations up to current every time there's an amendment?
Was it part of installation regulations to seal the chimney back in the mid 90s? And if not are we all expected to bring our boilers installations up to current every time there's an amendment?
It has always been a requirement to seal the annular space around the flue pipe on a BBU, preferably with a register plate , but more often than not the installer pushed a wad of fibre glass insulation up the gap, which I usually accept the reason for sealing the space, is to prevent soot remaining form Coal firing days, coal soot is high in sulphur and will corrode pipes in the opening (including the gas pipe!!) sealin the gap stops the soot falling into the opening. 
It has always been a requirement to seal the annular space around the flue pipe on a BBU, preferably with a register plate , but more often than not the installer pushed a wad of fibre glass insulation up the gap, which I usually accept the reason for sealing the space, is to prevent soot remaining form Coal firing days, coal soot is high in sulphur and will corrode pipes in the opening (including the gas pipe!!) sealin the gap stops the soot falling into the opening.
It has always been a requirement to seal the annular space around the flue pipe on a BBU, preferably with a register plate , but more often than not the installer pushed a wad of fibre glass insulation up the gap, which I usually accept the reason for sealing the space, is to prevent soot remaining form Coal firing days, coal soot is high in sulphur and will corrode pipes in the opening (including the gas pipe!!) sealin the gap stops the soot falling into the opening.
The reason for sealing the annular space is to prevent a possible (albeit unlikely) reverse pull from the chimney and to prevent debris falling down.
Airbricks usually dont allow much airflow and he would have had to measure them and count them up to calculate the free air of all the bricks. A vent underfloor like yours would normally be deemed not to standard now unless its ducted.
Airbricks usually dont allow much airflow and he would have had to measure them and count them up to calculate the free air of all the bricks. A vent underfloor like yours would normally be deemed not to standard now unless its ducted.
Update. I have had a look at all my airbricks outside and then discovered a special plastic one about 0.5m away from my floor vent. This must have been put in when the baxi was installed. There is nothing between this airbrick and the room vent and I believe it will satisfy the most zealous of NPower Servicemen. I asked why the previous NPower man had passed it all, he said he may have been a contractor? Have NPower left me "at risk" for the last 12 months? I got the impression from his glee that he would be able to find 50 ways to fail it but no way to make it go. Total area of airbrick openings is 472 holes at 8mm square so about 300cm2 which is 4 times the requirement. I think he should have done what I have done and worked it out himself. I'm not sure how a dozen previous services are OK and suddenly it's all At Risk?
The Baxi 401 installation instructions say the gap between liner and chimney brickwork should be sealed. Was rockwool insulation stuffed in the gap acceptable at the time? It would stop debris falling in and any reverse flow between liner and chimney. Thanks to everyone for input.
The Baxi 401 installation instructions say the gap between liner and chimney brickwork should be sealed. Was rockwool insulation stuffed in the gap acceptable at the time? It would stop debris falling in and any reverse flow between liner and chimney. Thanks to everyone for input.
Well I suppose if you let an Electricity Supply Co service your gas boiler?? 
Yeah I think you're right but it was at an irresistable NPower price and now I know why. So regarding the flue/chimney seal, where do I go if he refuses to sign it off? Is there a disputes appeal body of some sort or some sheet somewhere which we all sing from and there'll be a verse on acceptable sealing techniques which I can point out to him? Who can fit a sealing plate, a Sheetmetal worker or does it have to be a Gas Safe Person?
If you have 90% of the required ventalation for your fire and back boiler then there should be nothing to worry about !! That said you do have give careful considerations to other fuel burning appliances if situated within the same area.
The plate that is not in situ to seal the annular is only NCS and is only an advisory notice anyways.
Get a decent recommended gas safe engineer to have a look at the installation and I'm sure he/she will be able to advise you further.
The plate that is not in situ to seal the annular is only NCS and is only an advisory notice anyways.
Get a decent recommended gas safe engineer to have a look at the installation and I'm sure he/she will be able to advise you further.
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