Vaillant F.23 and F.22 error

[Pip89]

Hello

I’m hoping someone can shed some light on an issue we’ve been having with our Valiant standard boiler with gravity fed system, for the last week plus. Started around Monday last week, when we stopped getting hot water downstairs asks boiler sometime displayed F.23.

Gas engineer came round, said it was likely the pump, replaced the pump, but issue kept happening. Pump read 0.0 - 0.2 bar. He said it was sludge in the system and that the system needed power flushing, and three old radiators downstairs needed replacing. I was skeptical of power flushing, as most radiators and pipes have been replaced in the last 12 months, and water in the system looks clean. Anyway, we scheduled the power flush for a week and a half later.

Over that week problems seemed to get worse. Radiators upstairs didn’t get that hot either (especially the furthest one) and pump didn’t really go above 0.1 bar. Then a new error code on the boiler started displaying, F.22, lots of knocking in the boiler, and we lost heating completely. I went out for an hour, and when I got back everything was working again - all radiators hot, hot water in the tank, pump reading 0.7/0.8 bar, and everything has been working since then. Only issue is that it looks as though the boiler is also heating hot water when heating is on (the pipes going from the motorised valve to the tank are hot) even though the hot water is off.

Any idea what could be happening and what was restricting the flow of water in the first place? I’m reluctant to power flush if it’s not needed, and given all radiators are now red hot all over. I’m thinking a faulty motorised valve restricting flow, but if it’s the hot water one that’s faulty, I don’t know how that’d restrict heating flow.

Thank you
Rob

 

[CountryFan]

This post doesn’t make much sense. Pumps don’t measure pressure, you’ve said gravity fed, but then went on to mention pressure. Which model of Vaillant? Do you have a sealed system whereby you need to top the pressure up?

 

[Pip89]

Thanks for your reply.

Apologies, not sure if it’s pressure or the speed the pump is working at, but it currently is measuring 0.7 on the pump’s screen.

It’s an Ecotech 418 about 9 years old. It’s not sealed, there’s a tank in the loft that tops up the central heating.

Thanks

 

[CountryFan]

If it’s showing 0.7 sounds like it’s showing the output in watts, but to be certain, can you post a photo of the pump? Also, according to the manual there’s no f22 fault, which I’ve always known as low system water pressure. Can you also post a photo of the boiler?

 

[Pip89]

Yes sure, when I get home I’ll post some pictures. Thanks again for the help

 

[Pip89]

Hello

I’ve added some pictures of the boiler, the new pump, and the tank/pipes.

Thanks again

Rob

 

[CountryFan]

Hello

I’ve added some pictures of the boiler, the new pump, and the tank/pipes.

Thanks again

Rob

Ah, so I think it’s older than 8/9 years, but that’s ok. Yep, F22 on that particular model relates to dry fire (similar to a lack of water pressure in a pressurised system), I would check the cistern water level and make sure it’s able to fill back up in the loft, check the operation of the motorised valves, check any bypass fitted to the system and the pump valves are fully open. Have you expressed these concerns to the company? If you don’t want to use them again, I’d be seeking a refund as they haven’t done their job properly.

 

[Pip89]

Thanks so much. I’ll check all of that. Would this be connected to the original f.23 error with no heating downstairs and low pump operation? Just want to try and avoid it happening again.

Cheers
Rob

 

[CountryFan]

Certainly could be related, as F23 is a temperature difference, so if not the pump a circulation issue, such as a blocked cold feed.

 

[Pip89]

Thank you.

Thinking about it, when we got the f.22 error, and about half an hour before it started working again, I went into the loft and moved the ball valve slightly in the header tank which released a bit of water. Wonder if that cleared a blocked cold feed…

 

[CountryFan]

Wonder if that cleared a blocked cold feed…

No, it may have added water, but wouldn’t clear a blocked cold feed. The feed is water taken from the cistern, not the feed going to it.

 

[Pip89]

Ah that makes sense, thanks very much

 

[CountryFan]

@muggles - do you know anyone in Hertfordshire, near Watford, for @Pip89?

Thanks

 

[Pip89]

Sorry that should be Hertfordshire, near Watford

 

[muggles]

@muggles - do you know anyone in Hertfordshire, near Watford, for @Pip89?

Thanks

Dan Robinson (Jennings Heating Ltd) immediately springs to mind although he's Henlow so may be a bit far for him. Mike Walton might have done it but I think he's retired now