Insufficient Fall back to the boiler

[Richie_77]

Went to a Vailant 831 today that's been in for 3 years and theres next to no fall on the flue.
Ar'd the boiler, then had the inevitable chat with the landlord that the others guys said its ok they've put a landlords cert on it.
The flue is 7m long and in 125mm I'm now starting to doubt myself as it's been in working fine for the past few years though I know it's the right thing to do.
Anyone else coming across this problem? There seems to be a lot of mid 90s boilers in the middle of flats that are now dying
How have you all been getting over it? Are there any boilers in the market that don't need as much fall?
Twin flued Keston????

 

[stevetheplumber]

surely if there no faults its ncs?

 

[Billy Bob Bob]

its not AR IMHO,its not at risk of killing someone through incorrect fall on the flue,more at risk of damaging in the boiler

 

[GrahamM]

The standard flue has offset inner and no fallback required but extending this requires a couple of degrees fallback put into flue run.
As mentioned....why would this be AR if no fallback put into the extended flue run?
What is at-risk here?

 

[Roger Welton]

I've seen a couple of glowworms that have extended flues with no (minimal) fall back to the boiler the cond had eaten through the seals and outer flue casing, I ended up quoting to lower the boiler and rerun the flue though the landlord didnt want to know. According to the tenants it wasn't the 1st time it'd happened .

 

[wattsie1987]

The standard flue has offset inner and no fallback required but extending this requires a couple of degrees fallback put into flue run.
As mentioned....why would this be AR if no fallback put into the extended flue run?
What is at-risk here?

No offset inner that what the 87' bends job is.


As stated will very prematurely perish inner seales and cause and ID situation. I think ARing an appliance to prevent an ID is a safe game to be playing after all them seals could fail the moment you leave due to being installed against MI's and you'd just signed it off saying that it was safe. Who's right who's wrong I don't know but the man that went overboard will never be in the dock for it.

 

[ShaunCorbs]

No offset inner that what the 87' bends job is.


As stated will very prematurely perish inner seales and cause and ID situation. I think ARing an appliance to prevent an ID is a safe game to be playing after all them seals could fail the moment you leave due to being installed against MI's and you'd just signed it off saying that it was safe. Who's right who's wrong I don't know but the man that went overboard will never be in the dock for it.

+1 anything to do with flue or gas ar, it may not be but better safe than sorry

esp when they have got rid or ncs soon i believe