Vaillant fault code F.1288
Fault code F.1288 on a Vaillant heat pump (including aroTHERM Monoblock) means: Sensor defective or not correctly connected to the VWZ AI heat pump control module. Reset the appliance once. If the code comes back, a part is usually faulty, often a temperature sensor. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code F.1288 on a Vaillant heat pump indicates: Sensor defective or not correctly connected to the VWZ AI heat pump control module.
Applies to
Vaillant aroTHERM Monoblock, VWL 115/2 A 400 V, VWL 155/2 A 400V, VWL 55/2 A 230V, VWL 55/3 A 230 V, VWL 85/2 A 230 V, VWL 85/3 A 230 V.
Matching parts
Vaillant parts are available from Instalpunt; shipping to EU countries from €17.95 (€24.95 for more distant countries), usually 3–5 working days.
Parts by Vaillant series: ecoTEC plus · ecoTEC pro.
For fault code F.1288, the part involved is usually in the category: sensor.
Based on the cause, these original Vaillant parts fit (always check the type number of your appliance):
- Vaillant temperature sensor € 31.36
- Vaillant high-pressure sensor for e.g. aroTHERM VWL 55/3 A 230V 0020148037 € 226.08
- Vaillant sensor for e.g. aroTHERM VWL 115/2 A 400V 0020175869 € 15.68
Further reading on this cause
Other Vaillant codes with the same cause
- F.022 — Water pressure sensor defective, open circuit in the wiring harness, solenoid valve of…
- F.042 — Sensor not connected or sensor input short-circuited
- F.073 — Wire to the water pressure sensor is open circuit or has a short circuit
- F.086 — Contact S20 on the heat pump main PCB (HMU) open, incorrect setting of the maximum…
- F.094 — Flow rate sensor not connected or sensor input short-circuited
- F.514 — Sensor not connected or sensor input short-circuited
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does Vaillant heat pump fault code F.1288 mean?
Sensor defective or not correctly connected to the VWZ AI heat pump control module.
How do I fix fault code F.1288 on a Vaillant heat pump?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for Vaillant fault code F.1288?
That depends on the exact cause. In the Vaillant parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code F.1288 myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All Vaillant heat pump faults and codes at a glance →