Why your boiler might stop working in the cold weather

There has recently been a spell of extreme weather conditions in the UK.

The mass of snow fall has lead to temperatures dropping dramatically, which is very unusual for this part of Europe. This turn in the weather has meant that peoples heating systems and boilers have been working overtime to cope with the freezing climate. Since 2005 the only gas boilers allowed by law have been condensing boilers, around 80% of homes in Britain have these boilers. They effectively recycle waste heat and gas and increase the efficiency. However, they do not really make much difference compared to a traditional boiler when it comes to heating water. Although there is a possibility that they could stop working in the extremely cold weather if not installed or set up properly.

The way that condensing boilers work is by returning to a cooler temperature of 50-55oC. This cooler temperature meets with the hotter exhaust flue in the heat exchanger and this heat cause’s condensation to form in the heat exchanger, in very cold temperatures the pipe the condensation is taken away in can freeze and this is where the problem can occur.

If this problem occurs and the boiler attempts to work and realises its pipe is block it will more than likely try to work again and this constant course of retrying can in turn affect the boiler in a more serious way. Another possibility is that when the pipe freezes it may back up into the condensing boiler and this would be very expensive to repair.

It is recommended that you do not try to de-ice the pipe yourself; a condensing boiler should only be serviced or mended by a qualified plumber. Most plumbers use a wide condense pipe, this reduces the risk of freezing in your boiler.

One solution to prevent your condensing boiler freezing is to set your thermostat so the boiler runs both day and night but at a lower temperature during the night. Having your boiler operating through the night means that there is much less of a risk of the pipe freezing.

There are some very modern condensing boilers that actually have this facility built in, it is well worth hiring a plumber who is an expert in the type of condensing boiler to set it up for you.