Sabre 24 Combi Boiler Can anyone help?

[bm1289]

Can anyone help?

Went to new boiler install the other day with reports from customer boiler has explosive ignition.
This occurs when boiler starts to ignite..then boom!
Checked gas/burner pressures,Flue and tried varioys flue restrictor rings!

Vokera stated it must be flue or minimum burner pressure but all seem ok.

Also gettin 0.00010 reading on FGA which l think is high on a brand new boiler.

Flue length is 1600mm,also notice gas connection is 15mm into boiler but 22mm piped to last 300mm under boiler.

The banging also calms down when boiler starts hot!

Any help appreciated

Cheers!

 

[Billy Bob Bob]

if its new kick it in have you had the flue apart? sounds to me as if it vitiating

 

[wnjswozo]

if its a new install,why havent they called back the original installer,i would,nt get involved

 

[bm1289]

Yes Gasman was thinking the same combustion gas entering fresh air mix or something but flue seems ok.

Wnjswozo guy who done job injured himself at football so l offered to have a look at it.

 

[Billy Bob Bob]

sabre 24 is this a band b? flues can only be run 3 meters taking into account any bends or deflectors you will get vitiation or in the case of a performa band b explosive ignition and lock out

 

[bm1289]

This boiler apparently is a band D?

 

[Billy Bob Bob]

band d ??????????? hows that in there is it a exception?

 

[bm1289]

No idea? Wouldnt have fitted it personally but some mothers do have them!

 

[Billy Bob Bob]

its not a condenser, re check flue,look in mi,s at soft light settings,check gas pressures min/max within spec,look in mi,s re flue restrictors if required

 

[bm1289]

Cheers Gasman! Think l will spend bit of time on flue etc as you have stated but got me baffled!

Thanks for help!