Your heating questions answered

Smell gas? Turn off the gas at the meter, open the windows, do not touch electrical switches, and call the National Gas Emergency Service on 0800 111 999 straight away.

Winter tips

My boiler has stopped and the condensate pipe outside is frozen. What do I do?

In freezing weather, the plastic pipe that carries water from the boiler to the drain can freeze, and the boiler shuts down. To defrost it, pour warm (not boiling) water along the outside section of the pipe, or gently warm it with a hairdryer, then reset the boiler. Only use a hairdryer in dry conditions, keep it away from water, and never use it at the same time as pouring water. If it keeps happening, the pipe may need insulating or rerouting.

Why does my boiler keep losing pressure?

Most combi boilers run at around 1 to 1.5 bar when cold; your manual gives the exact figure. If the pressure keeps dropping, there may be a leak somewhere in the system or a fault in the boiler. You can top it up yourself using the filling loop, but if you are topping up often, call us to find the cause.

My radiators are cold at the top. Can I fix it myself?

Yes. Turn the heating off, let the radiators cool, then use a radiator key to bleed the air out until water appears. Check the boiler pressure afterwards, because bleeding can lower it.

When should I book my boiler service?

Before the cold weather arrives, ideally late summer or early autumn. Engineers get much busier once the temperature drops, and a service catches problems before you need the heating most.

What should I do with the heating if I go away in winter?

Leave the heating on a low setting, or use the frost protection setting if your boiler or thermostat has one. This helps stop pipes from freezing and bursting while you are away.

What are the signs of carbon monoxide, and do I need an alarm?

Carbon monoxide has no smell. Warning signs include headaches, dizziness, nausea and breathlessness that ease when you leave the house, a lazy yellow or orange flame on a gas appliance, and black marks around it. Fit an audible carbon monoxide alarm in rooms with gas appliances. If you suspect a leak, open windows, turn off appliances, get outside and call the Gas Emergency Service on 0800 111 999.

My heating works but the house never feels warm. Why?

Common causes are sludge in the radiators, thermostat settings, or a system that needs balancing. A service or power flush often solves it.

About DN Heating

Are you Gas Safe registered?

Yes. Our registration number is 533881.

Are you insured?

Yes. We hold full public liability insurance.

Do you charge for quotes?

No. Written estimates for new installations are free.

Do you offer emergency call-outs?

Yes, for boiler breakdowns and leaks. Higher rates may apply outside normal hours.

Do you work on oil or renewable systems?

No. We work on gas appliances only.

What is the difference between a heating engineer and a plumber?

Plumbers work on water pipes, taps and toilets. Heating engineers are qualified to work on gas appliances, boilers and heating controls.

Boiler servicing

How often should I have my boiler serviced?

Once a year. It keeps the warranty valid and the boiler safe and efficient. Book about a month before the service is due.

What is included in a boiler service?

We inspect the boiler, check the vents and flue, test the controls, look for leaks, clean the key parts and run a flue gas analysis.

Is a boiler service the same as a gas safety check?

No. A service is routine maintenance. A gas safety check is the inspection landlords are required to have.

Faults and problems

Why has my boiler stopped working?

Common causes are low pressure, a broken pump, a faulty thermostat or a failed pilot light. Check the pressure gauge and the power supply before you call.

Why are my radiators hot at the top and cold at the bottom, or the other way round?

Usually trapped air or sludge in the system. A radiator that is cold at the top can be bled with a radiator key. Cold at the bottom often needs a service or a power flush.