Frozen pipes and winter boiler breakdowns

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0333 320 4555 

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If you've got no gas or electricity, a water leak, or need an emergency repair, head to our emergency guide.

If you've got no gas or electricity, a water leak, or need an emergency repair, head to our emergency guide.

If your boiler stops working there are a few things that you can check before reporting a repair:

• Check your thermostat is set to the correct temperature.
• If your thermostat is battery operated check and replace the batteries if needed.
• Check your fuse box or circuit breaker for any tripped switches or blown fuses.
• Inspect the pilot light.
• Check the pressure.
• In very cold weather, check your condensate pipe. Take a look at our guide to defrosting a condensate pipe below for more information and instructions on how you may be able to resolve this issue yourself.

If your boiler is not working, it could be due to the condensate pipe from the boiler being frozen - this is the white pipe that comes out at the bottom of your boiler. 

In the vast majority of cases such problems occur where the condensate drainage pipe is located externally to the building for some part of its length.

Below is guidance on what to do if a boiler condensate drainage pipe has frozen. If you are at all unsure, then please contact us to report a repair.

Be aware that any water used can quickly freeze if it falls onto pathways so please take caution of any slip hazards.

1. Confirm that a frozen condensate drain pipe is the cause of shutdown.

It is important to confirm that a frozen condensate drainage pipe is the likely cause of the problem before taking any of the remedial actions suggested below. The condensate drainage pipe is a plastic pipe (black, white or grey in colour) connected to the bottom of your boiler.

If the following circumstances apply then it is probable that a frozen condensate drainage pipe is the cause:

• Outside temperatures have been below freezing for some time.
  
  
• The condensate drainage pipe runs through the wall and outside the property for part of its length, without any increased pipe diameter, any insulation on it, or other measures to prevent freezing. There may also be a problem if the pipe runs through an enclosed but unheated area, such as a garage or loft.
  
  
• The boiler has previously been working satisfactorily.

Shutdown due to freezing and blockage of the condensate drainage pipe will usually be indicated by a 'fault code' on the boiler’s digital display, although this may not specifically indicate freezing as the fault. Indication may also be given by some other alarm such as a flashing light, or by a symptom such as “gurgling” noises coming from the boiler.

Please refer to the boiler manual for guidance on fault codes/alarms and their meaning - call us if you are unsure.

2. Locate the blockage.

It is likely that the pipe is frozen at the most exposed point external to the building or where there is some obstruction to flow. This could be at the open end of the pipe, at a bend or elbow, or where there is a dip in the pipe in which condensate can collect. The location of the blockage should be identified as closely as possible before taking further action.

3. Thaw the frozen pipe.

The pipe can be thawed by applying a hot water bottle, a microwaveable heating pack (the sort used for muscular aches and pains) or cloths soaked in warm water to the exterior of the pipe, close to the likely point of blockage. Warm water can also be poured onto the pipe from a watering can or similar container. Do not use boiling water. 

You should not attempt to thaw a condensate drain pipe if you cannot easily reach it from ground level. Be aware that any water used can quickly freeze if it falls onto pathways so please take caution of any slip hazards.

4. Reset/re-start the boiler.

Once the blockage has been thawed and cleared, all you need to do is press the 'reset' button or turn after which the fault code should disappear and the boiler will re-start.

In most cases, once the condensate drain pipe is cleared and a reset has been carried out, the boiler will re-ignite using an automatic operating sequence.

If this reset/restart does not succeed you should contact us to report a repair.

5. Temporary remedial actions

If the pipe is successfully thawed and the boiler can be re-started then the following temporary remedial actions may help prevent re-freezing if the severe weather continues.

• If the external pipe is not insulated as recommended, you should try to rectify this by attaching suitable water-proof and weather-proof insulation over the outside of the pipe to prevent re-freezing. 'Class O' pipe insulation is suitable for external use and should be available from DIY outlets and plumbing/heating suppliers.
  
  
• During the cold spell it may help to temporarily run the heating system with the boiler thermostat (as distinct from the room thermostat) set to maximum. Turn back to the normal setting used once the cold spell is over.
  
  
• It may also help to temporarily set the central heating timer/programmer to 'continuous' (24hr) mode, setting the room thermostat overnight to around 15oC. Again, return to the normal settings once the cold spell is over.

6. FAQs

What is condensate and what does the condensate drain do?

High efficiency (condensing) boilers remove more heat from the combustion gases, resulting in additional water vapour which is collected within the boiler as condensate, and taken to a suitable drain via the condensate drainage pipe.

Why has my condensate drain only frozen recently?

Recently the UK has suffered from unusually cold weather, over prolonged periods. Existing recommendations for condensate pipe installation, such as pipe insulation, were based on prevailing UK weather conditions and may not be sufficient in the extreme conditions recently experienced across much of the UK.

Shouldn’t my condensate drainage pipe have been installed correctly in the first place?

British Standards, Building Regulations etc. currently allow condensate drainage pipes to be run internally, externally or a combination of these. These documents give recommendations on how to run the pipe and use insulation in order to reduce the possibility of freezing. This guidance was based on the UK winter conditions prevailing until very recently, however it may not have been sufficient to prevent freezing in extreme weather conditions.

A heating engineer cut the condensate pipe to get my boiler working and left the pipe discharging to a bucket as an 'emergency measure'. Is this acceptable?

It is recognised that in some instances (e.g. where an elderly person’s heating needs to be reinstated as an emergency measure) frozen condensate drainage pipes may have been cut in order to bypass the blockage. This has been done to allow re-ignition of the boiler, with condensate being collected in a suitable container as a temporary solution.

While not unsafe, this is not recommended practice and if such action has been taken then the condensate drainage pipe must be reinstated as soon as possible to reduce risk of freezing in future.

1. Switch off the water supply using the stop tap
2. Switch off the appliance causing the leak if possible, or avoid using it
3. Move your personal items from the affected area if possible
4. Place a container to catch the leak if possible
5. Soak up the leak with towels or mop if possible
6. If water has leaked near your electrics switch them off at the mains.

Please contact us immediately on 03333 204 555 to report this as an emergency repair. The line is open 24 hours a day, 365 days a year. If needed, we’ll send someone to help you as soon as possible to stop the leak or the damage caused. 

If your home has any escape of water, please move your items from the affected area to avoid damage if possible. As a housing provider, we do not insure your personal items, and we strongly recommend you have suitable contents insurance. 

You may have frozen pipes if:

• Your central heating makes gurgling sounds when it’s on. 
• Your boiler won’t turn on.
• There’s no water coming out of your taps, or just a trickle. 
• Your sink is clogged and your toilet is flushing slowly.

What to do

1. Turn off your stop tap by turning it clockwise, it’s usually found under your kitchen sink, but can be in your garage or cellar.
2. Once you’ve turned your stop tap off, turn on your cold tap in the kitchen.
3. If you have no water, this could be due to a frozen pipe somewhere in your home.  This may be the pipe which comes into your home near to where your stop tap is located. 
4. Carefully thaw the pipe using a warm towel, or if safe to do so a hairdryer in short bursts, ensuring you keep well away from water. If you can get water from a neighbour you could try a hot water bottle too. This could take a while, depending on how frozen and big your pipes are.
5. Do not use a blow torch or any kind of naked flame to try and thaw the pipe, as this could cause more damage.
6. Switch your stop tap back on to see if the water is running and check for any burst pipes in your home.
7. If your water doesn’t come back on or your pipes burst, report a repair.

Preventing frozen pipes

• Ensure all external supply pipes including outside garden taps are protected from the elements and are lagged.
• Outbuildings such as sheds / garages which have white goods in ensure that these are well insulated.
• In freezing weather, if possible, keep your heating on low. If you go away for any length of time, turn off your water supply at the stop tap and open all the taps. This will prevent your pipes from freezing in the cold winter temperatures.

Bleeding your radiators can make your home warmer and reduce the cost of your energy bills by removing air pockets.

• Get a radiator key, insert it into the groove in the valve, usually located at the top of your radiator.
• Using a tissue / cloth to protect your hand, slowly turn the key in an anti-clockwise direction, and listen for a hiss (this is the air escaping).
• When the hissing stops, turn the key clockwise again.
  After this you will need to check the boiler pressure, and if you need to increase the pressure you can do this by filling valve / loop (to about 1 - 1.5 bar).

Please note: This should only be done if you feel confident and competent to do so. If you are unsure or in doubt please contact us

Draught-proofing is one of the cheapest and most effective ways that you can take to stop the heat escaping and reduce your energy bills by approximately £70 per year:

• By blocking unwanted gaps around windows, doors and the floor that let the cold air in and warm air out, you’ll use less energy to heat your home. Energy Saving Trust provide advice on how to draught proof your property
• Window film is a form of temporary secondary glazing. By installing window film on your windows, you can help stop heat escaping through the glass. You can buy window film at most hardware shops and online and install it yourself or with the help of a professional.

Checking your boiler before the cold weather sets in can help us get it fixed in time for when you really need it.

• Turn on the heating via the room thermostat and the time clock.  In normal conditions, the room thermostat should be set between 18 to 21 degrees.
• Check that all your radiators get hot to the top (if not, it might mean that they need bleeding with a radiator key). 
• Check the pressure gauge on the boiler is above 1 and not above 2.

Did you know that if you sign up with the Priority Services Register with your energy suppliers (gas and electricity) you could get extra help. For example, if there is a power cut, someone can check up on you and provide hot meals. You may also want someone to check your meter regularly or move your prepayment meter.

To get this extra help, you can apply to be added to your electricity network priority services register. Find out more here: Priority Services Register