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Five minutes of checks in the right order saves a wasted call-out — and one smell stops the whole job dead. Briefing starts now.
Check the basics in order before you condemn the boiler: error code noted, pressure at 1 to 1.5 bar, thermostat and timer set right, fused switch on, one reset only. If you smell gas at any point, stop and ring 0800 111 999 — nothing else comes first. Boiler still down after the checks? Ring 020 4577 2888 any hour and report what you found.
Code, pressure, controls, power, one reset — in that order. Half of "dead" boilers are one of these five.
Run the checks like a pre-start inspection, and write down what you find as you go — that note is worth more to the engineer than an hour of description:
Any smell of gas and the checks end immediately. Leave the property, no switches, no flames, and call the National Gas Emergency Service on 0800 111 999 from a safe distance. Gas appliance work is not a DIY job at any point — by law it's work for a Gas Safe registered engineer.
Once is routine; repeatedly is a leak. Top up once through the filling loop — if the gauge slides again within days, stop topping up and report it.
A single dip after bleeding radiators is normal housekeeping: bleeding lets air out and pressure down, and the filling loop puts it back. The manual for your boiler shows the loop — usually a braided hose or built-in valve under the casing — and the target band, typically 1 to 1.5 bar cold. Fill slowly, close both valves fully when you're done, and you've completed the task.
The pattern to escalate is the slow repeat drop. That's water leaving the sealed system somewhere — often a weeping radiator valve, a joint under a floor, or in less happy cases a fault inside the boiler itself — and every top-up feeds fresh, oxygenated water to the leak, which also feeds corrosion. Log how fast it falls and ring it in. High pressure is a report too: a gauge stuck well above 2.5 bar, or climbing on its own, points at a filling loop not fully closed or an expansion vessel fault, and it wants a professional eye before the relief valve starts discharging down your outside wall.
Same discipline, two extra checks: oil in the tank, and one press only on the lockout button. Oil heating is standard kit across rural Mid-Ulster.
Plenty of homes around Cookstown — and most of them once you're out toward Kildress, Pomeroy, Sandholes or the lough shore — run oil-fired central heating, because much of rural Northern Ireland has no gas main. If the burner won't fire, check the tank before anything else. Sight gauges stick and float gauges lie, so if there's any doubt, a clean stick in the tank settles it. Running the tank near empty can also drag sludge from the bottom into the fuel line and filter, which is why a boiler sometimes fails just after a low tank was refilled.
Oil burners have a lockout light or button rather than a screen of codes on older models. The rule matches the gas side: one reset, and if it locks out again, leave it locked out. Repeated resets flood the combustion chamber with unburned oil and turn a small fault into a dirty, more expensive one. Frozen condensate pipes in a cold snap, blocked filters and tired nozzles are all fixable — report what you checked, including the tank level, when you ring.
Look at what changed last. A cold snap, a power cut, bled radiators, a new thermostat — the fault usually follows the change.
Boilers rarely die without a story. After a power cut, timers and smart controls can wake up with the wrong schedule or none at all. In freezing weather, a condensate pipe run outside — a common arrangement on kitchen-wall boilers in newer estates — can freeze and shut a condensing boiler down; the manual shows how to thaw it gently with warm (not boiling) water at the blockage. After radiator bleeding, low pressure is the prime suspect. After any pipework job elsewhere in the house, air in the system.
If nothing changed and the checks all pass, that's the point where the briefing hands over. Describe the sequence on the call — what works, what doesn't, what you've checked, radiators or hot water or both — and the plumber can tell you whether it needs an emergency visit tonight or a booked one in daylight, which is usually the cheaper option. If it's specifically hot water that's gone, take the no hot water briefing before you ring; it narrows things further.
Every make uses its own codes, so the manual or the manufacturer's website is the only honest decoder. Write the code down before you reset anything — it's the best clue the engineer gets, and clearing it without a note throws the evidence away. Codes commonly point at low pressure, ignition failure or a sensor fault, and the manual will say which are safe to reset yourself.
Once. If the boiler locks out again straight after a reset, it's telling you the fault is still there — repeated resets just hammer the same fault harder and can mask what's wrong. Note the code, leave it locked out, and get it looked at. The same one-reset rule applies to the lockout button on an oil burner.
Cold at the bottom usually means sludge — rusty deposits settling where the flow is slowest — which is a job for a proper system clean rather than a bleed. Cold at the top is the opposite problem: trapped air, and bleeding the radiator with a key fixes it. Check the boiler pressure afterwards, because bleeding drops it and it may need topping back up to the 1 to 1.5 bar band.
In general across the UK the boiler and fixed heating are the landlord's to repair, and the tenant's job is to report the fault promptly and keep any evidence — photos of the display, a note of when it stopped. Check your tenancy agreement and ring the landlord or agent before commissioning work yourself, or you may struggle to get the cost back.
The main page — how the line works and the patch it covers.
Go to home →Isolate, drain, make safe — the first five minutes in order.
Take the briefing →What you're cleared to try, and when it's NI Water's sewer.
Take the briefing →Hedged ballparks and the questions to ask before work starts.
Take the briefing →Switches, controls, pressure, oil, immersion — in order.
Take the briefing →Gentle thawing done right, and the lagging that prevents it.
Take the briefing →Damp patches, falling pressure and the stopcock test.
Take the briefing →Ring any hour, report what you checked, and a local plumber covering Cookstown and the townlands takes it from there.
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