F22 Dry error after power cut

[Flattry]

Last night we had a power cut. I woke up to our British Gas 330+ showing a F22 Dry error. The pump (Grundfos Alpha 2) has no lights on it, so either it’s been damaged (by the power cut?) or there is no power running to it. I cannot locate a fuse dedicated to the pump - it appears to be hard wired to a junction box. The only fuse is in the switch below the boiler - but the boiler has power. I switched that switch off and on again - no improvement.

RCD switches in the garage are all set to ON.

N.B. You may see in my previous thread that I turned the boiler power up from 10kW to 18kW. This appeared to solve my problem of lukewarm radiators. I suppose there’s an outside chance this might have damaged the pump?

Any suggestions?

 

[Exedon]

Turning boiler up won't have damaged pump.
If you have a multimeter and are competent to use it check there actually is power to pump.

 

[ianmcd]

the problem will be with the zone valve(s)

 

[dilalio]

Does pump come on if you put both HW and CH on? Or not at all?

 

[Flattry]

New information - the pump does in fact come on when the boiler comes on. I hadn’t noticed this because the pump is upstairs, the boiler is downstairs, and I hadn’t previously made it to the pump in time before the boiler stopped with the F22 error. But with an assistant I confirmed that the pump does come on while the boiler is attempting to start up - and then turns completely off when the F22 error stops the boiler.

So it seems like the F22 is now the issue I need to resolve (I’ve edited the thread title - hope this is Ok).

I tried turning the power down to 10kW again, and then reset the boiler. Same symptom occurred.

The boiler was previously working without any error messages, albeit the radiators weren’t heating up well. I thought I had cracked it yesterday by turning the power up to 18kW. It ran fine all day and the house got nice and warm. Now I’m worried I’ve triggered something worse.

 

[dilalio]

Water in the system?
As in do you have f&e tank or sealed (if it can be on this)?
Is there water in?

 

[Flattry]

We have a cold water tank in the loft and a smaller tank next to it. I don’t know how to check them. They look well wrapped up.

 

[dilalio]

They look well wrapped up.

Unwrap small one and have a look.
Push down on ball valve arm and see if water comes out.

Or... Maybe call in a heating engineer.

 

[Flattry]

I finally got a chance to investigate the cold water tank further. You were right to be suspicious. It’s almost completely empty, and was filling by a trickle. I wiggled the ball valve (which moves freely) and it stopped filling at all.

Flow out of taps throughout the house seems normal.

 

[jurassic sparkk]

I finally got a chance to investigate the cold water tank further. You were right to be suspicious. It’s almost completely empty, and was filling by a trickle. I wiggled the ball valve (which moves freely) and it stopped filling at all.

Flow out of taps throughout the house seems normal.

Have you got water coming out of the upstairs hot tap?

 

[Harry Bloomfield]

I finally got a chance to investigate the cold water tank further. You were right to be suspicious. It’s almost completely empty, and was filling by a trickle. I wiggled the ball valve (which moves freely) and it stopped filling at all.

The valve, attached to the float arm, is sticking, if it's not allowing water in when the float arm drops. Solve that, and your F22 error will be fixed.

 

[dilalio]

I finally got a chance to investigate the cold water tank further. You were right to be suspicious. It’s almost completely empty, and was filling by a trickle. I wiggled the ball valve (which moves freely) and it stopped filling at all.

Flow out of taps throughout the house seems normal.

Getting confusing now!

I was referring to the "small tank" which fills your central heating system with water and keeps it topped up.
It also acts as an expansion tank for the system and the water level in it will rise and fall as water heats and cools.

Is this the tank you are looking at/referring to?

The larger tank is your CWSC (cold water storage cistern) and supplies your hot (and usually upstairs) cold taps!

Which of the 2 is "almost empty" and not filling from the ball valve?

Let's be clear... Don't get the 2 confused.

Edit: and please try and quote the post you're responding to, it helps a lot!

 

[Johntheo5]

Last night we had a power cut. I woke up to our British Gas 330+ showing a F22 Dry error. The pump (Grundfos Alpha 2) has no lights on it, so either it’s been damaged (by the power cut?) or there is no power running to it. I cannot locate a fuse dedicated to the pump - it appears to be hard wired to a junction box. The only fuse is in the switch below the boiler - but the boiler has power. I switched that switch off and on again - no improvement.

RCD switches in the garage are all set to ON.

N.B. You may see in my previous thread that I turned the boiler power up from 10kW to 18kW. This appeared to solve my problem of lukewarm radiators. I suppose there’s an outside chance this might have damaged the pump?

Any suggestions?

If the (small) F&E cistern is full (normally ~ 1/3rd) and if F22 is still up try increasing the pump speed as F22 is flagged by low pump pressure or post a photo of the pump (running) LEDs if not sure of mode/setting.

 

[Flattry]

Getting confusing now!

I was referring to the "small tank" which fills your central heating system with water and keeps it topped up.
It also acts as an expansion tank for the system and the water level in it will rise and fall as water heats and cools.

Is this the tank you are looking at/referring to?

The larger tank is your CWSC (cold water storage cistern) and supplies your hot (and usually upstairs) cold taps!

Which of the 2 is "almost empty" and not filling from the ball valve?

Let's be clear... Don't get the 2 confused.

Edit: and please try and quote the post you're responding to, it helps a lot!

Apologies, hopefully I’m quoting correctly now.

It’s the larger tank which is near-empty and not filling. I haven’t tried unwrapping the smaller tank yet.

The valve, attached to the float arm, is sticking, if it's not allowing water in when the float arm drops. Solve that, and your F22 error will be fixed.

Does the large cold water tank supply water to the boiler? Is it possible that this float arm issue is a second, unrelated issue?

Have you got water coming out of the upstairs hot tap?

Yes I have, but not out of the shower.

 

[jurassic sparkk]

If incoming water main feeds Tank 1 (larger one)

and

Tank 1 feeds Tank 2

and

Tank 2 feeds the boiler, then your problem is with the ball valve. (larger tank)

OP - check if any stopcocks/isolation valves have been left closed.