Vaillant ecotec plus 824 f75 fault code help needed

[Citizenpayne]

Hi
I own regretfully a vaillant ecotec boiler. I had it serviced only yesterday and today (1 day later) the f75 fault code has appeared.
The plumber is due to turn up in the next 24 hours to investigate but I want some advice before he does to make sure that I'm not getting wripped off!
It seems strange how the boiler comes up with a fault message only 24 hours later?
I had the pump replaced just over 12 months ago so I'm hoping it can't be that and at the same time I had a magnet thingy installed and the boiler itself is only 7 years old.
At the time of the service I had the rads flushed as a couple of them where clogged up at the bottom and a regulator valve fitted to the shower.
And after that it all seemed to be working fine until this morning.
when I check the pressure it states 1.2 bar.

Any ideas??????????

 

[Tibbot]

if you believe he rips you off then why do you employ him?

 

[AlanE]

F.75 No pressure rise detected when pump started.

Possibles:
Water pressure sensor
Defective Pump
Air in heating system
Insufficient water in appliance
Check adjustable bypass
Connect external expansion vessel to return

 

[Agile]

Did you or he bleed radiators?

Did he do a proper service taking at least 20 minutes and involving opening the boiler?

Tony

 

[bazdaman]

Did you or he bleed radiators?

Did he do a proper service taking at least 20 minutes and involving opening the boiler?

Tony

WTF does spending over 20 mins on a service and opening it up make a difference to? Are you gonna say hes a cowboy if he didnt change the graphite seal?

 

[Bunnyman]

Maybe? Depends on age?