How to mend Vaillant Pressure Heating

my vaillant boiler is saying a code com on it ?

Vaillant ecotec plus 630?

how do I rectify the fault as detailed below?

Vaillant 828E - no hot water?

Vaillant vcw gb242 eh central heating problem?

Valiant thermostat , BMU-Err ?

Vaillant eco plus 531 boiler?

Hot water comes and goes!?

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

Vaillant F22 fault?

Valliant Eco tec 28?

my boiler will no work?

Vaillant Thermocompact Fault?

Vaillant ecotec 831 plus?

No hot water, intermittent when air temp drops?

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

Vailliant turbo max plus 824e?

Boiler over pressure on the hot-water side?

vaillant ecoTEC plus boiler fault code - how to fix?

Vaillant ecomax 828/2 e water pressure sensor?

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

Problem with the pressure in combi boiler?

What does f.25 mean?

Why is heating on at night?

how do I vent the heat exchanger?

Vaillant condensing boiler ecoTEC plus?

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

Vaillant Ecotech Plus 831 F22 fault?

Advice?

Vaillant igniting issue ( domestic ) not CH?