Alpha E16 fault codewhat it means and how to fix it
The control board cannot confirm the fan is running at the speed it asked for, so it will not let the burner light. This one needs an engineer.
Take care
Get a Gas Safe registered engineer to look at your Alpha E16
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What E16 means
Every condensing appliance checks that its fan is running before it will open the gas valve, because the fan is what clears combustion products out through the flue. E16 means that check failed: the board commanded a speed, read the feedback from the fan, and the two did not agree. There is a real safety interlock behind this, which is why the appliance will not fire at all rather than running at reduced output. The usual cause is simply a worn fan — the bearings dry out after eight to twelve years of running and the fan either slows or stops. But the same code appears when the flue itself is obstructed, because a restriction changes the load on the fan and therefore its speed. That is why a competent engineer checks the flue before condemning the fan, and why a fan swap that does not fix the fault usually means the flue was the problem all along.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Worn fan bearings | The most common cause by a distance on appliances past about eight years. Often preceded by weeks of a rumbling or grinding noise on start-up that the household stops noticing. | Common |
| Obstructed flue terminal | A bird nest, leaf debris, or render splashed into the terminal during building work. Changes the fan load enough to throw the speed check. | Occasional |
| Loose or corroded fan connector | The speed feedback signal is lost even though the fan is turning. Cheap to fix if that is genuinely all it is. | Occasional |
| Control board fault | The board is misreading a good signal. Diagnosed only after the fan and the flue have both been eliminated. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£180–£420
A replacement fan assembly is typically £280 to £420 fitted. If the fault turns out to be a connector or a flue obstruction it is a call-out charge of £80 to £140.
Typical UK prices including parts and labour, updated August 2026. Your quote may differ.
What other owners found
Nobody has shared what worked for them on this code yet. If you have had it, you would be the first — and it genuinely helps the next person.
Related Alpha fault codes
- C6 224Get it checkedThe fan is not reaching the speed the boiler asked for, so combustion cannot be confirmed as safe and the burner has been prevented from firing.Related: fan and flue
- F.32Get it checkedThe fan is not running at the speed the boiler expects, so combustion cannot be verified as safe and the boiler has locked out.Related: fan and flue
- E160Get it checkedThe fan is not running at the speed the appliance expects. Baxi direct engineers to check the fan and its cable, in that order.Related: fan and flue
- F3Get it checkedThe fan is not running at the speed the boiler expects, so it cannot confirm the flue is clearing and has stopped the burner firing.Related: fan and flue
- F9Get it checkedThe fan is not reaching the speed the burner control unit requires. The burner is blocked until it does.Related: fan and flue
- A03Get it checkedThe appliance cannot confirm the fan is running correctly, so it will not permit the burner to light. This needs an engineer.Related: fan and flue
Related guides
Common questions about Alpha E16
Is there anything at all I can check myself?
You can look at the flue terminal from outside, in daylight, from the ground. If there is an obvious nest or blockage that is useful information for whoever attends. Do not poke anything into it and do not remove the boiler casing — that is gas appliance work and it is restricted to Gas Safe registered engineers.
The boiler was making a grinding noise for weeks before this. Is that related?
Almost certainly, and it is the fan bearing giving you warning. Noise on start-up that settles once the fan is up to speed is the classic pattern before a fan fails outright.
Can I keep resetting it to get heat overnight?
It will not help. The fan interlock is a hard safety cut-out, so the burner physically will not light while the check is failing. There is no override and there should not be one.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
- Interviews with working engineers
Checked by Technical reviewer (Gas Safe registration to be displayed on appointment) on 5 August 2026.