Is it cold? Do you have a Vaillant? There's a good chance you've got yourself a frozen Vaillant (condense pipe). It's an easy fix...
Condensing boilers, of which Vaillant have plenty, have a weak spot in winter.
The condense pipe (which slow drips excess water) can and almost certainly will freeze if temperatures have dropped below zero.
To the naked eye, it can be guesswork so here’s how you’ll know it has happened.
(And cover up your naked eye, this is no time for nudism).
Vaillant frozen condense codes
Error code F28
Error code F29
Boiler producing a bubbling sound
Boiler producing a gurgling sound
Boiler is shutting down upon start up
If your Vaillant has one or more of the above issues and your condensate runs outside then here's some simple step to get it back up and running again.
If you suspect your Vaillant condensate pipe is frozen. Do not repeat your attempts to switch the boiler on or demand water from your system until the problem is rectified.
1. Locate the Vaillant's condensate pipe
The condensate pipe on your Vaillant boiler is most likely a thick, white plastic pipe that will exit externally at the wall nearest to your boilers location. If you're not at all confident in locating or identifying this pipe then you should have a heating engineer conduct this for you.
2. Apply warm water
Once you've located the outdoor section of the condensate pipe, apply hot water to the whole external section. Water between 60-70° would be ideal.
Thawing out your condensate pipe can take considerably longer than expected, sometimes several hours of repetitive effort. Don't make the assumption it's thawed out after just one application of hot water.
It's likely that you'll have to repeat this process several times and it will likely require several watering cans worth of hot water before the thawing begins to take place.
3. Apply a hot water bottle
If you have a hot water bottle then we would recommend first applying the hot water as mentioned above, following by holding or securing a hot water bottle against the outside area of the pipe for as long as possible. Applying both of these methods should greatly reduce the time it takes for the frozen condensate pipe to thaw out.
If the temperature is below -2 degrees Celsius, the hot water you pour onto your condensate pipe will freeze again very quickly. The application of the hot water bottle will prevent this and make it much more likely for the water to thaw, quickly.
4. Wrap/insulate the pipe
After you have managed to successfully unfreeze the condensate pipe of your Vaillant boiler, you'll need to prevent this happening again as it's very likely to freeze again quickly as soon as your boiler stops producing hot water.
Note that in very cold temperatures - wrapping the pipe alone will not be enough to thaw out the frozen condensate pipe.
You can wrap the pipe in any fabrics available to you, like cloths or old clothes - however, most DIY stores will sell specific materials that are designed to fit snugly around your condensate pipe and provide the best insulation to prevent further freezing. These pipe covers are usually available for under £10.
Pipe unfrozen, what next?
Once you're satisfied that your condensate pipe is no longer blocked by frozen water at its external point and you've also applied wrapping to the pipe in order to prevent it freezing again, then you're going to need to reset your Vaillant.
For most Vaillant boilers, you'll be able to reset it by pressing and holding the reset button on the front panel for approx. 10 seconds or until you can clearly see it has switched off and on again.
Upon restarting, any unusual sounds you were experiencing beforehand, fault codes or lights should no longer be occurring. If any of these issues still persist, we recommend double checking that your condensate pipe remains entirely unfrozen at every point and repeat the above steps if this isn't the case.
In most cases, this will solve the problem but if you're confident that the pipe is no longer frozen but you're still experiencing errors and/or fault codes, then you'll need a Gas Safe heating engineer to come out and perform an inspection of the boiler.
Been to this rodeo one too many times? Get yourself a quote for a new boiler, we may even be able to fit it as quickly as tomorrow.
