Frozen condensate pipe? Thaw it in 10 minutes
Every winter we get a rush of calls the moment temperatures drop. Nine times out of ten it's a frozen external condensate pipe — and you can usually fix it yourself.
You're not getting a call centre — you're getting Grant.
The same engineer quotes the job, does the work, and answers the phone afterwards if anything's not right.
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18+ years on the tools
Grant has been fixing boilers in Harlow since before smart thermostats existed.
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Most calls answered the same day, often within the hour.
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Not a national chain — your local engineer, your local prices.
The likely causes, in order
- External plastic condensate pipe — The white 22mm pipe running outside from your boiler. When temperature drops overnight it freezes solid, backing up water into the boiler and triggering a lockout.
What you can safely try first
- Locate the external condensate pipe (usually white plastic, 22mm)
- Pour warm (NOT boiling) water along its length from the top down
- Once thawed, reset the boiler at the front panel
- If it freezes again, wrap the pipe in pipe lagging or ask us to reroute it internally
Request a help · critical quote in your area
Real engineer reply — usually within the hour during working times. Fixed written quote, no commission-driven sales, 12-month workmanship guarantee.
- Gas Safe registered
- Same-day cover where possible
- Fixed written quotes
- Manufacturer warranties up to 12 yrs
Frequently asked questions
Will it happen again?▾
Yes, every cold snap, unless the pipe is lagged or rerouted. A permanent fix is running it internally — we can do this without wrecking your walls.
Is it worth calling you out?▾
If the DIY thaw works and it's a one-off, no. If it keeps happening, we'll lag or reroute the pipe — usually £120-180 for a permanent fix.
Related pages you might want
Still stuck? Get a real engineer on it
Call us if the DIY steps don't clear it — same-day response where possible, fixed price before any tools come out.