Overview
If your boiler has stopped working, check your pressure gauge (should be between 1-1.5bar), look for flashing error codes on the boiler display, and make sure your boiler has power and gas supply. Some common faults for Worcester Bosch and Vaillant boilers include low pressure, frozen condensate pipe, or trapped air. There are several simple fixes you can try before you call out boiler repair services in Leeds. Call a Gas Safe registered engineer for help with internal components.
Hi, I’m Steve Fearn and I’ve been repairing boilers and central heating across Leeds and surrounding areas for over 10 years. During that time I’ve had plenty of practice at diagnosing common boiler faults that people encounter at home. I service Worcester Bosch and Vaillant boilers as these are the 2 most popular brands that people own in the Leeds area. Now I’m going to share my knowledge with you!
Call Steve directly on 0113 513 5130 or 07791 586 147 about any of the faults described in this post. Call us immediately about these serious faults.
E9 - main heat exchanger has overheated.
C6 - fan failure or air pressure switch fault. Possible serious ventilation fault.
How do I diagnose my boiler isn’t working?
Do get in touch with us for a professional assessment but there are some quick checks you can try yourself.
General Quick Diagnostic Checklist
- Is your pressure gauge below 1 bar? If so, locate your filling loop and repressurise to 1-1.5 bar
- Are any error codes flashing on your boiler display? Take note of the code and find your manual
- Is your boiler switched on at the fused spur? Have you checked other gas appliances are working?
- Have you located the manufacturer's reset button? Press it, but once only! If it keeps cutting out, don’t keep pressing it!
- Does your boiler make a gurgling noise? Listen out for air traps in external condensate pipes
Pressing the reset button on your boiler can be effective, but if your boiler keeps switching off and there isn’t an obvious issue like low boiler pressure, you should call us. For now, read on about what the problem could be and why.
It’s also worth taking a closer look at your condensate pipe. If your boiler begins to make a funny gurgling noise before it shuts down, there’s a strong chance your external condensate pipe has frozen.
Diagnosing Worcester Bosch boiler problems
Worcester Bosch boilers are known for being extremely reliable but every boiler can have faults from time to time. Let’s look at some of the most common Worcester Bosch boiler problems to help you establish if you need to call out professional boiler repair company services from us in Leeds.
Worcester Bosch Problems & Errors
Problems with pressure
If your pressure gauge is showing less than 1 bar there are two possible causes. Someone may have bled a radiator recently or there is a leak in the system. To repressurise your system, look for your filling loop (generally found underneath your boiler) and open the valves until the needle reaches 1.5 bar.
If the pressure continues to drop, there is a leak somewhere in your heating system. You should call a professional boiler repair service.
No hot water or heating
Easy fixes to try before you call out an engineer include checking your programmer is on the correct setting. Some people forget they have set their boiler to ‘comfort’ or ‘disable’ heating/hot water. Also, ensure your thermostat is set to a high enough temperature to trigger the boiler into working.
Kettling noise
Kettling is that annoying boiling sound your boiler makes when there’s too much buildup inside or air is trapped inside your system. To fix trapped air, you can easily bleed your radiators. If your boiler continues to make this noise, get a professional to ‘descale’ your boiler.
Worcester Bosch Boiler Errors List
But what about actual boiler errors displayed on the LED display? Some are more urgent than others. Take a look at some of the most common boiler errors:
- E9 - main heat exchanger has overheated. Call Steve directly on 0113 513 5130 or 07791 586 147
- C6 - fan failure or air pressure switch fault. Possible serious ventilation fault.
- 9A/9U - Fault with HCM module or code plug. Get an engineer by calling us.
Per the official Worcester Bosch boilers technical document, errors beginning with ‘E’ or ‘C’ are serious and internal parts have failed, meaning you will need to call us to book a Gas Safe registered engineer.
Diagnosing Vaillant boiler problems
Vaillant have a slightly different error code system to Worcester Bosch boilers. The good news is you can still diagnose common boiler problems with similar ease.
Vaillant Boiler Errors
I’ve recorded the most common problems that occur with Vaillant boilers. Surprisingly there are quite a few. Here are the faults that I come across most during my yearly boiler service calls:
F.22 Low Pressure / Dry Firing.
The message means there isn’t enough water in the system. Vaillant has indicated this boiler fault is usually accompanied by a drop in pressure. Check your boiler pressure gauge. If low, use your filling loop to bring the pressure back to 1-1.5 bar. If your boiler continues to display F22 after trying to repressurise your boiler, then call a professional as internal components may have been damaged.
F.75 Pressure Sensor Fault.
Essentially your boiler thinks the pressure isn’t rising when your pump is activated. Unfortunately, this usually means your pressure sensor will need replacing or your pump investigated. Time to call out those boiler repairs.
F.27/F.28 Flame Detection fault.
Firstly, check your other gas appliances are working. If not, you may have a gas supply issue. If your other appliances are working, call a Gas Safe registered engineer on 0113 513 5130 or 07791 586 147 as soon as possible.
You should NEVER ignore a flame detection fault.
When to call boiler repair services in Leeds?
If you’re still reading then congratulations, you now know how to diagnose common boiler problems. Remember to never touch any internal parts of your boiler and always hire a Gas Safe registered engineer.
To prevent issues in the future, you should get your boiler regularly serviced by qualified professionals at S Fearn Plumbing & Heating Ltd.
Simple checks you can do include:
- Checking your boiler pressure monthly
- Bleeding your radiators every year
- Keeping your pipes lagged in winter
- Making sure your boiler has enough ventilation
Please Note
Never try to:
- Open up your boilers casing.
- Repair gas components.
- Reset your boiler if it keeps cutting itself off.
- Ignore any gas smells or BO results from running your boiler.
These tips will help prevent future problems. Always contact a professional on 0113 513 5130 or 07791 586 147 for internal issues.
Give us a call
Explore your options and start benefiting from a modern, energy-efficient boiler today.
