Glow Worm Ultimate 35c F28 Fault

[MrBosch]

Hi everyone, would massively appreciate any insights here. We had a complete new central heating install with a Glow Worm 35c Ultimate in April 2023. Zero issues until Nov 25 when an F28 fault appeared. Had Glow Worm out and they blamed the Saniflo pump as the engineer said when he removed the condensate connection water came out. A reset later and all good. Luckily they didn't charge me on this occasion.

The next day I fed a small hose funnel to the pump and tested it. Pump kicked in every time (tried it 10 times). Checked the drain and water was indeed flowing. Figured maybe the pump had glitched.

Fast forward today and same issue F28. This time I checked the condensate flexi and no water gushed out. Pump wasn't overflowing and again I tested it and fully working. I reset the boiler and all good.

Its due a service in a few weeks but I'm not sure what's causing the F28? Debating getting Glow Worm out to properly fault find as they were quick to blame the pump before. However if they find no fault I get charged!

What could it be that causes something intermittent like this? Thanks!

 

[denso13]

F28 is just not igniting which can be can be caused by a number of things. It looks like it was the condensate the last time, but it could be something completely different this time.

 

[Harry Bloomfield]

Fast forward today and same issue F28. This time I checked the condensate flexi and no water gushed out. Pump wasn't overflowing and again I tested it and fully working. I reset the boiler and all good.

Glow Worm Boiler F28 Fault Code: Troubleshooting The Issue

Experiencing a fault code on a boiler can be a source of stress for homeowners. The Glow-Worm boiler is known for its reliability, but like any machine, it

www.skillstg.co.uk

Seems it was just a coincidence that it worked the first time!

 

[CountryFan]

Definitely a few things to check. Check the gas emergency control valve is open fully, what about where the pump discharges to? If the pump isn’t working correctly it could be a buildup somewhere including inside the boiler. There’s other faults but I’m not at liberty to divulge as it’s gas related advice. Make sure the flue is clear too.

 

[MrBosch]

Definitely a few things to check. Check the gas emergency control valve is open fully, what about where the pump discharges to? If the pump isn’t working correctly it could be a buildup somewhere including inside the boiler. There’s other faults but I’m not at liberty to divulge as it’s gas related advice. Make sure the flue is clear too.

Many thanks for your reply. The pump picks up 300ml of water and that's pretty much what I'm seeing exit into the main drain.

Flue looks clear. Appreciate you can't say about the other faults. I'll ask some questions of my gas engineer at service time (I'll bring this forward to asap) and then potentially get Glow Work out if it looks warranty related.

 

[CountryFan]

Many thanks for your reply. The pump picks up 300ml of water and that's pretty much what I'm seeing exit into the main drain.

Flue looks clear.

And the emergency control valve?