8 Essential DIY Checks: What To Do If Your Boiler Stops Working

My Boiler is Not Working: First Steps for Homeowners in Horsham and West Sussex.

As a professional gas engineer, I know there are few things more frustrating than waking up to a cold home, especially during the colder months here in Horsham, West Sussex. 

If your central heating boiler suddenly stops working, your first reaction may be to panic and call an engineer immediately. 

However, before you reach for the phone, there are several straightforward checks you can perform safely yourself. 

Many common boiler issues can be quickly resolved by the homeowner, saving you the cost of an unnecessary call-out fee. 

I’m Andrew Tyler of Prime Boiler Care, and I specialise in providing reliable boiler service and repair across the Horsham District and Adur District, including areas like Southwater, Storrington, Billingshurst, Steyning, Henfield, Pulborough, Shoreham-by-Sea, Lancing, Southwick, and Sompting. 

I have put together this professional guide to walk you through the first essential steps. 

8 Essential DIY Checks Before Calling a Boiler Engineer.

Modern central heating systems are designed to communicate issues clearly, so this should always be your first port of call. 

1. Check the Boiler Display for Fault Codes or Lights.

 Walk directly to your boiler and inspect the front panel. 

Does it have a light flashing or a specific alphanumeric fault code displayed (e.g., F1, E133, etc.)? 

Note down the code. 

If the boiler is completely blank, proceed to the power checks. If a code is present, a simple restart (reset) may clear the temporary fault, but if it persists, it points to a specific internal issue that will require professional help. 

2. Verify the Power Supply and Fuse Spur.

A surprisingly high number of call-outs are simply due to a lack of power. 

Locate the fused spur switch, which is usually a white switch with a small red neon light located near the boiler. 

Ensure this switch is in the 'On' position and that the red neon light is illuminated. 

If the light is off, you may have a tripped circuit breaker or a blown fuse (it typically requires a 3-amp fuse). 

Do not attempt to work on the electrical wiring yourself. 

3. Check the Timer/Programmer Settings.

Make sure your central heating timer or programmer is active and actually requesting heat and/or hot water. 

A manual override may be required if the time settings have been inadvertently changed or have been switched off. 

4. Confirm the Room Thermostat is Calling for Heat. 

Is the room thermostat turned on, and is the temperature setting higher than the current room temperature? 

If your thermostat is a wireless model, ensure the batteries are still working. If the batteries are flat, the thermostat cannot communicate with the boiler. 

5. Review the Boiler Thermostat.

Check the control dial or interface on the boiler itself. Is the boiler turned on, and is the central heating temperature control dial turned up to an adequate level? 

6. Check Your Gas Supply.

If your boiler is gas-powered, you need to ensure gas is actually reaching the property. 

The quickest check is to turn on a gas cooker or hob, if you have one. 

If the hob ignites, your gas supply is active. 

If you have a prepayment gas meter, check that there is adequate credit available. 

7. Inspect the System Pressure (Minimum 1 Bar).

Most domestic boilers operate within a pressure range of 1 to 1.5 bar when the system is cold. 

Locate the pressure gauge (manometer) on your boiler. 

If the needle has dropped below 1 bar, the boiler may have shut down as a safety precaution. 

You can usually top up the pressure yourself using the filling loop, but be very cautious not to over-pressurise the system. 

If you need to top up the pressure frequently, this indicates a leak that requires professional investigation. 

8. Check the Condensate Pipe (During Freezing Weather).

While most modern boilers do not have a pilot light to worry about, they do have a condensate pipe, which safely removes acidic wastewater. 

This pipe usually runs outside and can freeze in sub-zero temperatures, causing the boiler to shut down. 

If the pipe is blocked or frozen, you can gently thaw it by pouring hot (not boiling) water over the frozen section. 

This is typically one of the last DIY checks. 

When to Call a Professional Gas Engineer.

If you have systematically run through the checklist above—checking the power, programmer, thermostat, gas supply, and pressure—and your boiler is still not running, it is time to call a professional. 

Do not attempt to remove the boiler casing or tamper with internal components. 

This is both dangerous and illegal unless you are Gas Safe registered. 

As a certified professional for all boiler repairs in Horsham, Steyning, Lancing, Shoreham-by-Sea, and the surrounding areas of West Sussex, I am ready to diagnose and repair the issue safely and efficiently. 

Whether you are experiencing a boiler fault code in Pulborough or need an urgent repair in Southwick or Sompting, Prime Boiler Care is here to help. 

Call Prime Boiler Care today for professional boiler service and repair. 

Andrew Tyler Prime Boiler Care Suite 54, Standby Business Centre Foundry Lane Horsham, West Sussex, England, RH13 5PX 

01403 814602