Appliance Help - Frozen Condensate Discharge Pipes
Background
The vast majority of all Gas boilers sold in recent years will be the high efficiency type; these types of boiler extract more energy from the gas being burned to generate the heating and hot water for your home. As a result of this your fuel bills will be lower saving you money, reducing the carbon emitted from your boiler and helping to reduce global warming.
How do I know if I have a high efficiency type boiler?
1. Consult your user manual.
2. The name badge fitted to your boiler may include the letters HE (high efficiency).
3. Look underneath the boiler amongst metal pipes there will be a plastic pipe approximately 22mm in diameter which will either run internally to waste or externally to a suitable drain.
Below is a typical Baxi high efficiency boiler control panel:
What is condensate?
As a result of being more efficient your gas boiler will produce water vapour formed in the combustion process, this water vapour is then cooled to produce water condensate.
Good practice when installing condensate drainpipes
Good practice dictates condensate discharge pipes should wherever possible be run inside your property connecting to internal drainage. This prevents it from being affected by extremely low external temperatures and eliminating the potential to freeze.
Why can condensate freeze?
Because it may not always be possible to run the condensate discharge internally in your property. If the condensate discharge pipe is fitted externally certain precautions need to be taken to prevent the condensate from freezing, which could stop your boiler working in prolonged periods of sub zero temperatures. Below are some examples of frozen and poorly fitted external condensate discharge pipes:
How do I know my condensate pipe may be frozen?
Depending on your boiler a frozen condensate discharge pipe may be indicated in a number of ways depending on the specific model you have:
• Error codes either E133 or E4 on the alphanumeric boiler display
• No flame symbol displayed
• Gurgling water noises coming from the boiler.
• Please note your boiler may have some minor differences to those shown below but the error code or flame failure indication will be the same.
This shows a boiler with the error code E133. The boilers screen alternating between E1 and 33 displays this code.
This shows a boiler with the error code E4. The boilers screen alternating between E and 4 displays this code.
Other models will have the flame failure symbol shown below on the control panel indicated with a solid or flashing red light.
If you now suspect your condensate pipe is frozen before phoning heateam you may wish to try the following:
1. Locate the blockage
It is likely that the condensate discharge pipe is frozen at the most exposed point external to the building or where there is some obstruction to flow. This could be the open end of the pipe, at a bend or elbow, or 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.
2. Thaw the frozen pipe
The first method of thawing the frozen condensate discharge pipe is to pour hot water (NOT BOILING) over the outside of the frozen section of the pipe using a suitable container, such as a watering can. See below:
This could take around 30 minutes but the boiler will not ignite until the pipe is fully thawed. If your boiler is out of use as a result of the frozen condensate discharge pipe you could heat the water using a kettle or microwave.
A second method of thawing a frozen condensate discharge pipe is to use a hot water bottle or heat wrap - usually used to ease muscular discomfort. These heat wraps are available at your local pharmacist. If you have chosen to use a hot water bottle hold it against the frozen section until the condensate discharge pipe is fully thawed. This process may also take some time but again the boiler will not ignite until the blockage is fully thawed.
Please note you should not attempt to thaw a condensate discharge pipe, if it cannot be easily accessed from ground level. Also do not attempt to disconnect the condensate discharge pipe at any time during this process. Only attempt to thaw a frozen condensate discharge pipe if you feel competent to do so.
3. Reset boiler
Once the condensate discharge pipe has fully thawed, the boiler will need to be reset using the reset switch. Once reset the boiler should fire up and run as normal.
4. What should I do if I cannot reset my boiler?
If you are unable to reset your boiler, don't worry you can contact us on the number below and we will be more than happy to arrange a visit with one of our qualified engineers
For heateam Customer Contact Centre call 0844 3352266
See heateam website for opening hours
What can I do to prevent this from recurring?
You will need to speak with a Gas Safe Registered installer who may recommend some remedial action that can be taken to prevent reoccurrences of the condensate discharge pipe freezing. Some options may include:
• Identify alternative route inside your property (or use a condensate pump)
• Increase external pipe diameter externally to 32mm
• Ensure all exposed condensate discharge pipework is insulated with waterproof insulation
• Fit trace heating
• Ensure condensate discharge pipes are connected into soil pipes only (110mm)
Where else can I get information?
The HHIC (Heating and Hot Water Information Council) have published industry guidance for householders, which can be viewed by following the link below.
http://www.centralheating.co.uk/heating-advice/boiler-condensate-drain-freezing
FAQs
Q. I've tried the above and the boiler is still displaying the error code?
A. Don't worry, give us a call and we can send one of our engineers out
Q. What if I don't feel comfortable doing this?
A. If you don't feel comfortable contact your installer or give us a call, however there may be a charge for this.