Vailant ecotec plus 824 f75

[Barry98]

The vain if my life , had 5 in the last two week horrible horrible horrible

 

[arran197]

Get an f75 kit. Replaces the flow pipe and relocates the pressure sensor to resolve the issue.

https://www.heatingspares247.com/flow-switch/vaillant-service-kit-f75-0020023721-p-2265.html

 

[abc_plumb]

I've had this one before, spent ages working it out.
The pump had slowed down, I know you said you checked this but was the pump strong.
i weak pump can give this fault.

 

[Whyme]

Ps, when you take the old sensor out jab something in the pipe itself to make sure that aint blocked.X

 

[Leo21]

How do you check for a weak pump on these? When you take the centre screw out, it pee,s out a jet of water. Usually in the direction of the pcb!

 

[abc_plumb]

With loads of towels,
measure the peeing out! Lol
take the pump screw out and see if it shots out have one hand on the control to switch off