How to mend Vaillant Ecotec Pro 24

how do I rectify the fault as detailed below?

Vaillant F22 fault?

Valiant thermostat , BMU-Err ?

Valliant Eco tec 28?

No hot water, intermittent when air temp drops?

How do I fix f22 error on my Vaillent Ecotec Plus boiler?

Vaillant ecomax 828/2 e water pressure sensor?

Vaillant igniting issue ( domestic ) not CH?

how do I vent the heat exchanger?

Vailliant turbo max plus 824e?

Vaillant vcw gb242 eh central heating problem?

my boiler will no work?

Problem with the pressure in combi boiler?

What does f.25 mean?

Vaillant 828E - no hot water?

Advice?

Vaillant ecotec 831 plus?

Hot water comes and goes!?

Boiler over pressure on the hot-water side?

vaillant ecoTEC plus boiler fault code - how to fix?

Vaillant Thermocompact Fault?

Why is heating on at night?

Vaillant condensing boiler ecoTEC plus?

my vaillant boiler is saying a code com on it ?

Vaillant Ecotech Plus 831 F22 fault?

how to fix water pressure its down at bottom of grey part?

can i replace my Potterton EP2 2 way programmer with a Center EHE0200361 RF?

Vaillant ecotec plus 630?

Vaillant eco plus 531 boiler?

Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?