The Heating and Hotwater Industry Council (HHIC) has launched a guide to condensate discharge pipe installation, updating its previous recommendations. It has also published a customer information booklet, which gas engineers can use to explain the risks and any remedial action that may be required.
Following extreme UK weather patterns such as “the Beast from the East”, the heating industry identified a number of actions that could help to protect heating systems against frozen condensate.
HHIC director Stewart Clements says: “In March, representatives from across the heating industry met at the HHIC offices to review and discuss the matter of frozen condensate, which caused a high number of domestic boilers to stop working during the extreme weather that caused major disruption across the UK.
“We called this ‘summit’ to discuss what needed to be done to prevent a repeat of the problems that the industry and, of course, consumers had experienced. It meant looking at existing regulations around boiler installation, preventative measures to protect external pipework from freezing, and what advice and guidance consumers needed.
“From the feedback we received, it became clear that a significant proportion of installations were not to current standards and manufacturers’ instructions. The opportunity to connect to an internal drain point such as a soil stack or sink waste was not being taken. 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.
“As a result, the HHIC agreed to update current industry guidance, which would assist engineers with both installation and assessment of current condensate discharge pipes, which they can and should review during any visit to the appliance such as a service, repair or when replacing a heating system.
“In addition to this guidance, all other technical requirements for condensate discharge installation given – in the first instance, the appliance manufacturer’s installation instructions or, if referred to by the appliance manufacturers, British Standard BS 6798:2014 – should still be followed.”
It is important to note that the appliance manufacturers’ instructions take precedence over British Standards and should be adhered to, helping to ensure correct appliance operation, and validity of any warranty.
An efficient condensing boiler will generate around 2 litres of condensate an hour at a temperature of around 30°C-40°C, and this needs to be piped to the waste water system or to a drain. Industry specification and current BS 6798 states: “Wherever possible, the condensate drainage pipe shall be terminated at an internal foul water discharge point.” Where there is no other option than to run the pipe externally, the pipe needs to be increased to at least a 30mm inside diameter and insulated to help prevent freezing.
Greater awareness and enforcement of this standard is needed, says HHIC, so that wherever possible an internal connection is used, as well as more emphasis on supporting solutions such as the correct type of insulation or trace heating products. Even internal pipes in unheated areas require insulation.
You can download the installer guide here.