With summer well behind us and autumn in full-swing, many of us will have switched the heating on for the first time by now. Falling temperatures can put additional pressure on your boiler and heating system, especially if it is suddenly used a lot after being dormant all summer.

And as winter approaches, the pressure is only going to increase.

The condensing boiler: a blessing and a curse

All modern gas boilers are now of the 'condensing' type – which is good news because they are considerably more efficient than many older boilers, meaning lower bills and a smaller carbon footprint.

But there is a downside: condensing boilers don’t handle low temperatures very well.

Frozen condensate pipe

Condensing boilers are so efficient because they re-use waste gas to heat water. Moisture in this gas is condensed, and must be expelled via a moisture pipe which runs into a drain outside your home. If this 'condensate pipe' freezes in colder weather, it may burst, leaving your home without hot water and heating. However, if you discover that your condensate pipe has frozen, it is relatively easy to thaw out. Simply apply heating pads or a hot water bottle. Assuming the pipe didn’t burst, you can simply reset the boiler and you should be able to enjoy hot water and heating once again.

Your condensate pipe should be lagged with insulation to prevent freezing taking place.

Frozen pipes in general

Aside from your condensate pipe, your regular water pipes may also be susceptible to freezing, which can mean water does not reach your boiler. This will of course leave you without hot water or heating.

If you can identify the frozen pipe or pipes, you might try and tackle the problem yourself. Use the mains stop cock to turn off the water supply, then use a hair dryer or a hot water bottle to gently thaw the pipe out.

Burst pipe: what to do

If you discover a burst pipe, turn off the stop cock and drain the water from the cold taps. Flush all toilets. You should then shut off the heating system and drain all the water from the hot taps. Immediately call a professional for assistance.

Other boiler problems

The arrival of lower temperatures prompts many of us to turn the heating up high. But running your system at very high temperatures can put a lot of pressure on your boiler’s components, increasing the chances of a breakdown. Most modern boilers now have an ‘economy’ setting: this is usually set at 75F/23C. Sticking to this temperature should help prevent a breakdown – as well as save you money.

Pilot light going out

Your boiler’s pilot light can go out at any time of year, but considering you use your heating much more in winter, it is more likely to extinguish around this time. The pilot light usually goes out due to a blockage or an issue with the ignition system. Refer to the manufacturer’s handbook to get the pilot light lit again. Call a professional if it won't re-ignite.

Tips to keep your gas boiler and heating system working well:
  • Frequent checks

Even if it’s not cold right now, it’s a good idea to turn on your heating a few times a month, just to check it is still working properly.


  • Bleed your radiators

Check your radiators for cold patches. If you find any, you may need to bleed your radiators. These cold zones are caused by trapped air. Once the air is released, your radiators should distribute heat evenly again.


  • Keep your boiler flue clear

And as mentioned above, make sure your condensate pipe is insulated to prevent freezing.


  • Get your boiler serviced each year

A faulty gas appliance could have lethal consequences. Make sure you have yours checked by a Gas Safe engineer annually.


  • Check the pressure

If your water or heating is not working as well as usual, your pressure could be low. This may be due to a leaky pipe – so check this first. If you don’t find any leaks, use the valve on your boiler to increase the pressure. Check the manufacturer’s handbook for more details on this.


Oil-fired boilers: tips for winter
  • It is recommended every oil-fired boiler is serviced annually by an OFTEC qualified engineer
  • Check your oil tank for any signs of damage
  • Clear away any leaves or debris so you can check for cracks easily
  • Consider a top-up: oil prices are often cheaper before winter sets in, so it could be a good time to buy more oil