Isar30 L9 Fault

[bevelsingle]

Right, I know these are probably the worst boilers many will come across.
I have an L9 fault
Pressure good.
Vented of air
Pump is only receiving 40ish volts! (loom checked with pump disconnected) So I know pump will not turn, and hence why L9 but why low voltage.

Boiler had not been switched on for a while as exp vessel shate itself and the inevitable removal of boiler and reinstatement meant there was a bit of water about.

any ideas please?

<Moderators note>
I have deleted the duplicate. If you use the "report" button you or denso can ask for a thread to be moved.

See also
//www.diynot.com/diy/threads/gas-fitters-only-forum-the-combustion-chamber.114690/

 

[gigz]

Have you tried spinning the pump to see if its siezed ? You want approx 220 ohms on pins 4 & 6. Also check the pcb is'nt melying in the middle.

 

[bevelsingle]

Yep, pump is free.
If I came to the job fresh I would suspect PCB (have replaced plenty as most of us have), but on re-filling, the boiler ran DHW first off but stopped when CH run.