Low-pressure codes (e.g. F1, E119)
Among the most common. They mean the system pressure has dropped too low for the boiler to run safely. Topping up via the filling loop often clears the code — but if it keeps returning, you have a leak or a failing part behind it. Our guide to losing pressure walks through the causes.
Ignition and ‘no flame’ codes
These mean the boiler tried to fire but didn’t detect a flame. Causes range from a gas-supply issue to a faulty ignition lead or flame sensor. A single reset is worth trying; if it locks out again, stop and call a Gas Safe engineer — this is gas, and not one to poke at.
Frozen condensate pipe (common in winter)
In cold snaps the external condensate pipe can freeze and block, and the boiler shuts down with a fault. Thawing the pipe gently (a jug of warm — not boiling — water) often gets things going again. If it keeps freezing, the pipe may need re-routing or lagging.
When to reset, and when to call
One reset is reasonable. If the same code returns immediately, or you smell gas, or the code relates to the flue or a sensor, don’t keep resetting — book an engineer. Note the exact code and your boiler model; it saves time and often means we arrive with the right part.
Seeing a code you can’t clear? Tell us the code and your boiler make when you call — our Gas Safe engineers cover South Manchester and Cheshire and can often fix it on the first visit.
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