Boiler
hints & tips.

• Turn the thermostat down one degree. Most homes are comfy at 18–21°C, and every degree lower cuts your bill.
• Combi boiler? Lower the heating flow temperature to about 60°C. The boiler runs in its efficient “condensing” mode more of the time and you'll barely notice the difference. Rooms take a little longer to warm up.
• Hot water cylinder? Don't turn the cylinder temperature down yourself. It needs to stay hot enough to stop bacteria growing, so ask us to set it up properly.
• Turn off combi “pre-heat” or “eco/comfort” keep-warm if you don't need instant hot water. It stops the boiler firing up through the day just to keep water warm.
• Use radiator valves (TRVs) to turn down rooms you don't use. Keep an eye out for damp in cold rooms.
• Let the heat out: move sofas away from radiators and tuck curtains behind them.
• Bleed radiators and get a yearly service. Both keep the system running at its best.

• Combi boilers make hot water on demand, so usually only the heating needs a timer.
• System or regular boilers with a cylinder have two schedules: one for heating and one for heating the cylinder. Heat the cylinder an hour or so before you need it, such as before morning showers, not all day.
• Set heating to come on 30 minutes before you get up or get home, and off 30 minutes before bed or before you leave. The house holds its warmth.

• A smart thermostat like Hive or Nest lets you set schedules, control the heating from your phone, and turn it off when you're out.
• Put the thermostat in a room you use, away from radiators, sunny windows, the kitchen and draughts, or it will read the wrong temperature.
• Use “away” or holiday mode rather than turning everything off in winter. It keeps a low frost-protection temperature.
• We fit and set up Hive and Nest, and show you how to use them before we leave.

• The gauge should read about 1–1.5 bar when cold. It rises a little when the heating is on, which is normal.
• Too low (under 1 bar): the boiler may lock out. You can top up through the filling loop only if your manual shows how. If it keeps dropping, there's probably a leak, so call us.
• Too high (near 3 bar, often in the red): turn the heating off, let it cool and call us. Don't try to drain it yourself.
• Pressure drops after bleeding radiators are normal. Just check and top up afterwards.

1. Turn the heating off and let the radiators cool down.
2. Find the bleed valve at the top corner of the radiator. Hold a cloth underneath.
3. Use a radiator key to turn the valve about a quarter turn anticlockwise. You'll hear air hiss.
4. When water starts to drip out, close it again.
5. Check the boiler pressure and top up if it's dropped. Then turn the heating back on.

• Cold at the top, warm at the bottom: usually trapped air. Bleed the radiator.
• Cold at the bottom or in the middle, warm at the top: usually sludge (rust and dirt) sitting in the radiator. Bleeding won't fix this. It needs a system clean or power flush.
• Whole radiator cold while others are hot: check the valve is open, then call us. It may need balancing or a sticking valve freed.

• Cold patches at the bottom of radiators, a noisy boiler, slow-to-heat rooms, or dark, dirty water when you bleed a radiator.
• Sludge makes the boiler work harder and can shorten its life. It's the most common reason for pump and heat-exchanger problems.
• A power flush or chemical clean pushes the sludge out, and a magnetic system filter stops it building up again. We usually recommend both when fitting a new boiler.

• A rumbling or kettle-like boiling noise is usually limescale or sludge on the heat exchanger, so water overheats in spots.
• Banging pipes, gurgling or whistling can be air, low pressure or a frozen condensate pipe.
• Check the pressure and, in a frost, the condensate pipe. If the noise carries on, turn the boiler off and call us. Don't ignore it, as it gets worse and costs more to fix.

1. Turn the boiler off.
2. Find the frozen part, usually the most exposed bit outside or near the drain.
3. Pour warm, not boiling water slowly along it, or hold a hot water bottle or heat pack on it. Boiling water can crack the pipe.
4. Turn the boiler back on and reset once.

To stop it happening again, ask us about insulating the pipe or re-routing it.

• Book your boiler service in late summer or autumn, before the rush and the first cold snap.
• Run the heating for 15 minutes in early autumn to make sure everything works.
• Lag outside pipes and the condensate pipe.
• Know where your stopcock and gas meter valve are.
• Going away? Leave the heating on a low frost setting instead of fully off.
• Keep our number handy: 01592 744440.

• Safety: checks for gas leaks, flue problems and carbon monoxide risks.
• Efficiency: a clean, well-set-up boiler uses less gas.
• Fewer breakdowns: worn parts get spotted early, before a cold-weather failure.
• Keeps your guarantee valid: manufacturer guarantees usually need a yearly service by a Gas Safe engineer, with records kept. Our new boilers come with an 8-year guarantee, so keep that service book up to date.
• Landlords need a gas safety check every year by law.

Get a free yearly reminder →

• Carbon monoxide (CO) has no smell or colour and can kill.
• Fit an audible CO alarm (marked EN 50291) in rooms with a gas appliance, and test it monthly.
• Warning signs: headaches, dizziness, nausea or tiredness that ease when you leave the house; a lazy yellow or orange flame; sooty marks around the boiler.
• If you suspect CO: turn the appliance off, open windows, get outside, call 0800 111 999 and get medical advice.

• You smell gas (call 0800 111 999 first), or your CO alarm sounds.
• A fault code keeps coming back after one reset.
• The pressure keeps dropping, or it's near 3 bar.
• Water is leaking from the boiler or pipes.
• Banging, kettling or other strange noises that don't stop.
• Anything that would mean opening the boiler. That's a job for a Gas Safe engineer.