Avoid Boiler Breakdowns This Winter: How to Prevent Frozen Condensate Pipes
Cold snaps are great for cosy nights in, but they’re also the time we see a spike in boiler breakdown calls. One of the most common causes? A frozen condensate pipe.
If your boiler has suddenly stopped working during freezing weather, there’s a good chance the condensate pipe has frozen and is blocking the system from draining properly.
What is a condensate pipe (and why does it freeze)?
Modern boilers (especially condensing boilers) produce condensation as they run. That water needs to drain away through a small pipe often routed outside. When temperatures drop below freezing, that external section can freeze, causing a blockage and triggering a boiler fault.
Quick checks you can do before calling an engineer
There are a few simple checks you can do that may help you avoid a call-out.
For a clear step-by-step guide, use this link:
Check your boiler’s pressure
Look at the pressure gauge (or digital display).
Typical “healthy” range is often around 1.0–1.5 bar when cold (varies by system).
If it’s very low, your boiler may lock out. If you’re comfortable topping up via the filling loop, follow your boiler manual. If not, call us.
Look for a fault code / flashing light
Note the code (e.g., EA, F1, etc.) and the boiler make/model.
This helps us diagnose faster if you do need a visit.
Try a simple reset (once)
Use the reset button as per the boiler instructions.
If it immediately locks out again, don’t keep resetting repeatedly.
Check the thermostat and heating controls
Make sure the thermostat is turned up and calling for heat.
Check programmer/timer settings (is it on “off” or “holiday”?).
If it’s a wireless thermostat, replace the batteries.
Check if other gas appliances work
If your gas hob/cooker works, gas supply is likely OK.
If nothing gas-related works, you may have a supply issue—contact your gas supplier.
Frozen condensate pipe checks (common in cold snaps) If your boiler has stopped during freezing weather, this is a big one:
If it’s frozen, you can gently thaw it using:
Warm (not boiling) water poured over the pipe
A hot water bottle
Warm towels/ cloths
Focus on the lowest/most exposed section and any bends.
Once thawed, try a single reset.
Avoid: boiling water, blowtorches, naked flames, or anything that could crack the pipe or damage fittings.
Check for obvious leaks
If you can see water dripping from the boiler/pipework, or you’ve got a ceiling stain below the boiler area, switch the boiler off and call.
Check the condensate drain isn’t blocked (indoors)
If your condensate runs into an internal waste pipe, check for obvious blockages/smells/back-up at the waste point (don’t dismantle anything—just a quick visual check).
When to call Etta Plumbing
If you’ve tried the checks above and your boiler still isn’t working, an engineer visit may be required and we’re here to help.
Get in touch
Email: Info@ettaplumbing.co.uk
Call: 01332 204533
We’ll get you back up and running as quickly as possible and help you reduce the chances of it happening again.
