Glow Worm boilers – fault finding

Although Glow Worms are budget boilers, they don’t tend to have a bad reputation or suffer from numerous faults. With parts reasonably priced and easily available, a quick call out by an engineer will usually have your boiler back up and running.

Some of our FAQs about plumbing and heating relate to boiler faults, so we thought we’d take a look at some of the most common faults that you might spot with your Glow Worm boiler. Don’t forget, though, that it’s important not to try and attempt repair yourself, as all repairs should be carried out by a qualified engineer.

Fault Code F16

If you spot code F16 flashing on your Glow Worm Ci model, this indicates a flame detection fault. Your boiler may need servicing and its probe may need to be replaced or cleaned. It may also be that your boiler isn’t properly igniting, which an engineer can fix.

Fault Codes F1, F4 and F3

These fault codes are relatively common amongst Flexicom CX boilers. F3 is a fan speed fault, while F1 and F4 relate to ignition faults. An engineer can replace the fan or PCB and may also need to replace your boiler’s ignition leads.

Fault Code F9

This is the code most dreaded by home owners and engineers alike, as it’s fairly generic and so could relate to a number of different faults, from issues with the diverter valve to circulation and pressure problems. Often, the culprit is a system which has been inadequately flushed, leading to issues where the plate heat exchanger has sludge build-up. Once your engineer has assessed the problem, they can flush the system, top up the pressure or even replace the pump, as needed.

Fault Code F14

If your Flexicom CX boiler flashes an F14 code, you’ll notice that the manual states that this indicates a defective gas valve. Often, that’s not actually the case, and an engineer can assess whether you need a new gas valve or a new wiring harness or PCB.

With over 20 years’ industry experience, you can rely on us with our team of expert engineers at Shaw’s Plumbing and Heating if you notice any of these fault codes flashing on your Glow Worm boiler this winter.