Boiler fault codes
Vaillant F32 Fault Code: Fan Speed Not Confirmed
Published
Vaillant display
F32
What it means
A fan fault: the boiler cannot confirm its fan is running at the right speed, so it switches off rather than light the burner.
Safe to check yourself
- Check the fused spur feeding the boiler is on and its fuse has not blown
- Look at the flue terminal outside for anything blocking it, such as a nest, bag or packed snow
- Reset once and listen for the fan starting
Call an engineer if
- F32 returns after one reset
- You heard grinding, rattling or a rising whine from the boiler before the fault
- There is a burning smell from the boiler
- You smell gas: open windows, turn off at the meter if safe, avoid switches, then leave and call 0800 111 999
F32 on a Vaillant is a fan fault. The fan that drives air and exhaust through the boiler is not reporting the speed the boiler expects, so it refuses to light. Causes range from a loose plug to a failed fan or circuit board. Reset once; if F32 comes back, it needs an engineer.
What does F32 mean on a Vaillant?
Your boiler’s fan pulls in combustion air, mixes it with gas and pushes the exhaust out through the flue. Before it will open the gas valve, the boiler checks the fan is spinning at the speed it has asked for, using a Hall sensor inside the fan that reports back to the circuit board. If the reading is wrong or missing, the boiler shows F.32 and stays off.
Vaillant’s owner fault code page simply calls F32 a fan fault and lists a defective fan, a faulty plug or harness, or a circuit board problem. It says this needs an engineer. The installer manual adds a blocked fan and a defective Hall sensor. None of those sit outside the casing.
Is there anything I can check?
Very little, and that is deliberate: the fan is sealed into the gas and combustion circuit. What you can do is rule out the simple things around it.
- Power: make sure the fused spur next to the boiler is switched on. A display that is on but flickering or resetting is worth mentioning to the engineer.
- Flue terminal: from outside, check nothing is stuffed into or wrapped around the terminal. Do not poke anything into it.
- Listen: after a reset, you should hear the fan spin up before ignition. Silence, grinding or a whine that rises and dies are all useful details for the engineer.
- Reset once. If F32 comes back, leave it off.
Never remove the casing to spin or free the fan by hand. Behind the panel are mains voltage and the gas and flue seals. A gas smell means windows open, the meter valve off if you can reach it safely, and a call to 0800 111 999 from outside.
What usually fails, and what it costs
On boilers several years old the fan itself is a common culprit: the bearings wear, the motor gets noisy, and eventually the speed signal drops out. Before replacing it, a good engineer checks the plug at the fan and the connector on the circuit board, because a loose or corroded connection gives the same code for a fraction of the cost.
As a guide to typical market prices, As a guide to typical market prices, a new genuine Vaillant fan for an ecoTEC-sized boiler retails at roughly £200 to £350 as a part depending on the model.. Labour is on top, and a fan change is gas work: the burner seals are disturbed, so the engineer must run a combustion check with a flue gas analyser before handing the boiler back.
If the fan is fine and the fault persists, the circuit board is the next suspect. That is a larger repair, and on an older boiler it is worth asking whether repair still makes sense.
Getting it fixed
Gas work is carried out by Gas Safe registered engineers. You pay the £60 call-out, and the repair price is agreed with you on site before any work starts. Tell us the boiler model from the front panel label, which helps with the right fan part. For other Vaillant codes, see our Vaillant boiler repair page or the Vaillant fault code list.
Questions people ask
Can I reset a Vaillant F32 fault?
Once. If the boiler starts and runs normally, note the date in case it happens again. If F32 returns, the fan, its wiring or the circuit board needs checking by an engineer.
Why is my Vaillant noisy before showing F32?
A fan with worn bearings often gets louder, with a whine or rattle, before it fails completely. That noise is an early sign the fan is on its way out.