A flue is a critical part of a safe and efficient boiler system, but with changes to industry regulations and numerous manufacturer options to consider, it can be a challenge for installers to keep up.
To help, Baxi Potterton Myson has compiled five top tips on how to ensure a flue system is properly installed.
1 – Determine the correct lengths
The design and diameter of the flue will determine its maximum allowable length which, if exceeded, will impact the ability of the boiler to function properly. For example, a 60/100 millimetre concentric flue fitted to a system or combi boiler can be a maximum equivalent length of 10 metres (this takes into account that any 90 degree bend has an equivalent length of 1 metre and any 135 degree bend has an equivalent length of 0.5 metre). If the installation needs the flue to run for a distance above this, then the flue size can increase to 80/125 millimetres, allowing for a maximum equivalent length of 20 metres.
2- Give careful consideration to siting
Where the flue is sited is important because the flue gases discharged from the terminal are cooler and less buoyant than those of a non-condensing boiler, and usually form a visible plume of water vapour. This can lead to water ingress and damp issues, and can also be a nuisance to neighbours. There are a range of flue accessories such as balcony kits, plume deflectors and plume displacement kits that can be used to move the pluming to where it won’t cause a problem.
3 – Create the appropriate support
It might seem obvious, but secure support is critical for all flue systems, because without it, they may dip along a long horizontal length, leading to an accumulation of condensate water which can cause ignition, noise or boiler lockout issues. For all Baxi Potterton Myson boilers, the flue must be supported with a purpose supplied clip at a minimum of once every metre.
4 – Do the right tests
Testing is a key part of any boiler commissioning process, and this remains the case for the flue system. A flue integrity test, which should be conducted using a flue gas analyser, will confirm that all the flue joints are correctly assembled and there is no recirculation of the combustion products.
5 – Stay informed on industry changes
Finally, make sure you stay up to date with the latest regulations. For example, when considering the siting of a flue remember that there is a prescribed set of minimum distances from building openings and adjacent obstructions specified in I.S. 813 Domestic Gas Installations.
For more information about Baxi Potterton Myson visit www.baxipottertonmyson.ie