Cold weather problems and how to prevent them

Older non-condensing boiler installations in unheated spaces, such as a garage, outhouse, or loft space, rely on good insulation of pipework, cold water storage (CWS) and feed and expansion (F&E) tanks. The boilers themselves often need additional frost thermostats and pipe thermostats: these override the normal heating controls and fire up the boiler in the coldest of temperatures.

Some boilers also have a spring-loaded safety valve screwed into the cast-iron heat exchanger to relieve the expanding pressure on the boiler if the cold feed and vent pipe should become frozen.

Many newer heating systems use combi or system boilers, and system boilers usually heat an unvented hot water cylinder, which means that CWS, F&E tanks and pipework in roof spaces are a thing of the past. Newer boilers have built-in frost protection instead of relying on external controls.

It’s important to insulate all exposed pipework in unheated spaces, but the most likely cause of damage to a modern boiler in sub-zero temperatures will be a frozen condensate pipe that has been run externally.

When the condense pipe freezes, condensate backs up inside the boiler causing damage that could lead to expensive repairs.

External condensate drains

You should only consider fitting an external condensate drain connection if internal gravity or pumped connection is impractical to install.

Where the condensate must be run to an external drain, make sure you follow the manufacturer’s instructions and BS 6798*, which require the condense pipe to be run internally as far as possible before going outside. The pipe

Top tips to protect the home

Insulation: prevention is better than cure

There are many good reasons for insulating the home, including insulating the water pipework in unheated or exposed areas. For a low initial outlay, insulation will save on energy and reduce heating costs, and help to reduce the impact of greenhouse gases. Insulating water pipework prevents the likelihood of freezing in prolonged cold periods. Damage to property – including heating systems – can happen when pipes initially become frozen or when the temperatures rise again and damaged frozen pipework thaws out to expose leaks.

Make sure your customers know where their pipes are and how to shut the water off. When pipes freeze, speed is critical: the quicker the water is shut off, the better the chance of preventing serious damage.

Make sure gas appliances are serviced every year in accordance with the appliance manufacturer’s instructions. This helps to ensure that they operate safely and helps prevent breakdowns at the time when they are needed most.