Vaillant Heat pump F.22 error
F.22 is identified by Vaillant support as low water pressure in the heating system. Follow the official, model-scoped checks and service boundary below.
Reference source listed as Vaillant UK official heat-pump fault-code support.
Open official source ↗low water pressure in the heating system
Follow the exact model manual. If the system pressure is below 1 bar and the owner is competent, use the filling loop to raise it slowly to 1–1.5 bar; if pressure is above 1 bar or the fault returns, contact a Vaillant engineer. Do not open fixed panels or test live circuits.
Typical symptoms
Likely causes
Start with the least invasive explanation and stop if the check requires internal electrical or sealed-system access.
Safe next steps
- 1Record the complete F.22 display and the full Vaillant heat pump model
- 2Confirm that the displayed code matches the linked official Vaillant source
- 3If the system pressure is below 1 bar and the owner is competent, use the filling loop to raise it slowly to 1–1.5 bar; if pressure is above 1 bar or the fault returns, contact a Vaillant engineer.
- 4Stop and arrange model-specific service if F.22 returns
Step-by-step repair
- 1If the system pressure is below 1 bar and the owner is competent, use the filling loop to raise it slowly to 1–1.5 bar; if pressure is above 1 bar or the fault returns, contact a Vaillant engineer. No internal component replacement is verified from F.22 alone.
Repair details
The published checks normally need no replacement part. Internal repair cost is model- and region-specific; obtain a written Vaillant service quote after diagnosis.
Exact Vaillant model manual, Flashlight and dry towels for external checks, No live electrical test tool
No replacement part is confirmed by F.22 alone. Confirm the exact model, failed component, and manufacturer part number before ordering.
What not to do
- Do not force covers, use sharp tools, or repeat the test if F.22 returns.
Preventive maintenance
- 1Keep the washer level, use the detergent specified by the exact model manual, and keep accessible hoses, locks, and filters clear.
Frequently asked questions
What does F.22 mean?
Vaillant identifies it as low water pressure in the heating system.
Can I replace a part from the code alone?
No. Confirm the exact model and manufacturer diagnosis first.
Did this fix your appliance?
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