22 fault code, Glow worm

[billski]

Got a Glow worm 18 flexicom with f22 fault.
I've replaced both flow & return thermistors, bleed all rads of air, removed the pump and cleaned it, it all seems fine and pump is strong, checked wiring continuity and that's all good. Boiler is only 6 years old and Glow worm have said it sounds like the main heat exchanger is blocked causing a restriction. Apparently they are prone to this. They don't sell a gasket kit to remove it and clean it so they've suggested I'd have to replace it! Probably better to replace the whole boiler, but it's only 6 years old.
Any one suggest anything else?
I've cleaned out the condense trap as well.

 

[ShaunCorbs]

Does it try to fire at all or just faults out

 

[billski]

Does it try to fire at all or just faults out

It fires and runs for about 10 or 20 seconds.

 

[ShaunCorbs]

Electrodes fine

What’s the fan pressure like against manufacturers listing

 

[Harvest Fields]

What is the pressure on?

 

[billski]

It's an open vent system.

 

[Harvest Fields]

It's an open vent system.

Circulation issue? Bypass set correctly? Pump
Ok? Blocked cold feed?

 

[Scott_D]

Got a Glow worm 18 flexicom with f22 fault.
I've replaced both flow & return thermistors, bleed all rads of air, removed the pump and cleaned it, it all seems fine and pump is strong, checked wiring continuity and that's all good. Boiler is only 6 years old and Glow worm have said it sounds like the main heat exchanger is blocked causing a restriction. Apparently they are prone to this. They don't sell a gasket kit to remove it and clean it so they've suggested I'd have to replace it! Probably better to replace the whole boiler, but it's only 6 years old.
Any one suggest anything else?
I've cleaned out the condense trap as well.

It can’t be serviced??
Does this model have a stainless heat exchanger or Ali type?

 

[billski]

It can’t be serviced??
Does this model have a stainless heat exchanger or Ali type?

Ali heat exchanger. Called the manufacturer and they told me they do not do a gasket kit to strip the heat exchanger down and clean it!

 

[king of pipes]

You could try jet flushing it with x400 or x800 disconnect from the system in this case, if it works then maybe consider doing the system to . Kop