Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 44·3.16
Debris collection space
Where a flue cannot be cleaned through the appliance, a debris collecting space that is accessible for emptying and suitably sized opening(s) for cleaning should be provided at appropriate locations in the flue.
Where a flue cannot be cleaned through the appliance, a debris collecting space that is accessible for emptying and suitably sized opening(s) for cleaning should be provided at appropriate locations in the flue.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet L - Combustion Appliances and Fuel Storage Systems.pdf