Boiler not working

[Keith Melnyk]

Hi guys last year you helped me tremendously and i,m in trouble again. I have an Alpha 28cd and this morning it didn,t fire up.A and B are flashing alternately,which usually signifies a drop in pressure.The needle was just on the line at the lower limit so I topped it up.It still doesn,t fire up and A and B are still flashing,also no hot water any ideas? TIA Keith.

 

[Mottie]

I had a problem with my Vaillant when I came home from holiday once and it wouldn’t fire up after taking it out of the 'off' mode. Switched it off, switched it back on and been working fine since. Might be worth trying that.

 

[Keith Melnyk]

Thanks for your reply.Managed to get engineer out,turn out to be primary pressure valve. All sorted now.

 

[Keith Melnyk]

Should have read primary pressure switch