News | Published on 29th Mar 2018

Heating industry statement on condensate pipes March 2018 in response to the widespread effects of the UK’s recent freezing weather conditions

In 2005 the Government changed the Building Regulations so that only boilers of a certain high efficiency could be installed for both replacement and new installations, with regards to gas and oil boilers. This high efficiency can only be achieved using condensing technology, where the boiler extracts heat from the flue gases so the existing heat within is released and ‘recycled’ back into the water being heated in the boiler.

This can only be achieved when the flue gas temperatures are reduced to around 50c, (prior to this legislation the flue gases leaving a boiler were around 130c minimum). Cooling to this level creates water, known as ‘condensate’ which needs to be dispersed to the waste water drainage system or a soakaway.

An efficient condensing boiler will generate around 2 litres of condensate water an hour at a temperature of around 30-40°c. This needs to be safely disposed of, within the buildings waste water system. Industry specification and current British Standard 6798 states that ‘wherever possible, the condensate drainage pipe shall be terminated at an internal foul water discharge point’.

However, there are circumstances in which there is no other option than to run the pipe externally. In this instance the pipe needs to be increased to at least a 30mm inside diameter and insulated, or supporting solutions such as internal insulation or trace heating products should be fitted to help prevent freezing.

During the peak of the extreme weather experienced earlier in 2018 that caused major disruption across the UK as a whole, the UK’s gas emergency number control room took over 40,000 calls from members of the public – the vast majority were not boiler fail emergencies but people seeking help because their gas boiler had stopped working due to their condensate pipe becoming frozen.

From the feedback, we have received, it has become clear that there was a significant proportion of installations that were not installed to current standards and manufacturer’s instructions. That said, we are acutely aware that in extreme weather conditions external pipework carrying water is at risk of freezing, particularly when there is a high wind chill factor. Obviously it is difficult to legislate against the most extreme weather conditions. However, we believe it is time for the government to act. 

Industry will now;

  • Seek greater enforcement and strengthening of the current building regulations.
  • Review current installation techniques available that may reduce condensate pipework freezing and produce good practice guides to installers.
  • Continue to advise the consumer and heating engineer to assess that the condensate discharge pipe is compliant with the manufacturer’s instructions during their boiler service.
  • Update the HHIC ‘Consumer Guide to gas boiler servicing’ to include a condensate pipe check.
  • Include condensate pipe inspection as an item for the CIPHE consumer home compliance group
  • Update the benchmark gas boiler commissioning checklist to emphasise correct condensate installation.
  • Support the industry with product innovation and development.
  • Actively raise awareness with consumers of the standards required to minimise the risk of frozen condensate. Including recommending the use of professionally qualified heating engineers (Gas Safe, OFTEC etc.). This note gives brief guidance for householders on what to do should they find themselves in this situation.
  • Actively raise awareness with heating engineers of the standards and relevant building regulations required to prevent frozen condensate.
  • Bring about an industry ‘extreme weather protocol’ which will include proactive advice and warning activity.
  • Support government reviews currently being undertaken which aim to improve compliance with building regulations.
  • Liaise with gas industry training providers to ensure Gas Safe engineers have all the relevant underpinning knowledge required- whole job competence.