A boiler that's stopped working is one of the most common calls we get — and a surprising number of the time it's something you can check safely yourself in two minutes before booking an engineer. Here's what to look at, in order.
Most combi boilers should read between 1 and 1.5 bar when the heating is cold. If it's below 1 bar, the system has likely lost pressure and needs topping up via the filling loop (check your boiler manual for the exact steps — it's usually a simple valve under the boiler). If pressure is above 2.5–3 bar or keeps climbing on its own, don't try to fix it yourself — that needs an engineer.
It sounds obvious, but a thermostat accidentally knocked to a low temperature, switched to the wrong mode, or with a flat battery (on wireless models) accounts for more "boiler not working" calls than you'd think. Check the display is lit, the target temperature is above room temperature, and the time/schedule hasn't been accidentally changed.
If you have an older, non-condensing boiler with a visible pilot light, check it's still lit. Most boiler manuals include re-lighting instructions if it's gone out. If it won't stay lit or keeps going out, that's usually a sign of a fault (often the thermocouple) and needs a Gas Safe engineer — don't keep re-lighting it repeatedly.
Modern boilers display a fault code when something's wrong. Look this up in your boiler's manual (or search the exact model and code online) before calling — it helps the engineer bring the right parts and can sometimes point to a simple fix like a reset. Common codes relate to low pressure, ignition failure, or a flow/return sensor fault.
Check other gas appliances (a gas hob, for example) are working. If nothing gas-powered is working, check your gas supply hasn't been interrupted and that the emergency gas shut-off valve hasn't been knocked closed. If you smell gas at any point, do not attempt any checks — leave the property, call the National Gas Emergency Service on 0800 111 999, and only re-enter once it's confirmed safe.
Still not working after these checks? That's when it's time to call a Gas Safe registered engineer. We offer 24/7 boiler repair across Edinburgh, plus annual boiler servicing to catch problems before they leave you without heating. Call 0131-285-0958.
Related reading: How to Prevent Frozen Pipes This Winter · How Much Does an Emergency Plumber Cost in Edinburgh?
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