How safe is my boiler?

A faulty boiler can have several knock-on effects. It can cost more to run, leave you without heat in the winter and, at worst, is dangerous. So how do you know which boiler issues are minor and which require more urgent action? The following advice has been sourced from British Gas which has looked at the most common boiler problems and given each a priority rating. 'Low' signifies it’s a minor issue, 'High' means you’ll need a gas engineer as soon as possible.

1. My heating and/or hot water isn’t working

A pressure or thermostat issue may be behind your heating or hot water not working. These can be simple to fix – see points 2 and 8 below. Alternatively, a broken part, such as a diaphragm or valve could be responsible, or it could be an airlock in the system. If you’ve addressed any pressure or thermostat problems and you’re still not getting heat or hot water, a registered engineer will be able to help diagnose other causes and fix them. Not dangerous but not ideal.

Is your boiler safe


2. My boiler has lost pressure

Your boiler pressure should sit at 1.5 bar . If you’re having trouble getting heat from your system, low pressure could be the culprit. It’s easy to diagnose through a quick check of your boiler gauge and is usually easy to fix. Lost pressure is a nuisance, but it’s not life-threatening. If you can’t put it right yourself, give a an engineer a call.

Boiler safety and whether you need a boiler service


3. My boiler is leaking water

You should never see water coming from your boiler. If you do, it might be a sign that an internal part has failed. While it’s not necessarily dangerous, you should switch off your boiler to prevent your electrics short-circuiting and to stop water damaging your home or belongings. Don’t try to fix a boiler leak yourself. Always let a gas engineer take a look.

How to hire a gas safe engineer


4. My boiler is making a lot of noise

Gurgling, banging or whistling sounds should probably be looked at. They’re likely to be caused by air or a build-up of material inside your central heating. It’s not a dangerous situation but if left unattended, a build-up could lead to a boiler breakdown and expensive repairs.

Take out boiler insurance to cover the cost of boiler servicing

5. My condensate pipe is frozen

Frozen pipes are a common cause of boiler shutdown, but the issue should resolve itself once the pipes thaw. You can try unfreezing them yourself by pouring hot (but not boiling) water on the pipe end. A hot water bottle or other form of heat wrap might also work. After a while, switch the boiler off and on again and if it’s still not working, contact an engineer.

 Checking for carbon monoxide leaks

6. My thermostat isn’t working

A faulty thermostat isn’t dangerous, but it is annoying. So make a few simple checks – have the timings been accidentally changed or the temperature settings adjusted? Try increasing the temperature on the thermostat controls to see if it triggers the boiler into action. If it doesn’t and the thermostat seems to have become less accurate, or started doing its own thing, it might be time to replace it.

Boiler safety advice

7. My boiler keeps turning itself off

Low pressure, a thermostat issue, or maybe lack of water in the system could cause your boiler to switch itself off. If you can’t identify the source of the problem, a gas engineer will. As with all boiler faults, it’s better to nip it in the bud. 

Boiler safety tips