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
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
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 September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Alpha fault codes
- E01Get it checkedThe appliance tried to light and could not confirm a flame, so it has locked out. In winter a frozen condensate pipe is the most likely reason.Related: same brand
- E10Get it checkedAlpha describe E10 as the primary pressure switch operating. Refilling to their green band usually clears it, but the switch itself is on their own list of causes.Related: same brand
- E02Get it checkedThe overheat thermostat has tripped. Almost always this means water is not moving through the appliance properly rather than that it is running too hot.Related: same brand
- E60Get it checkedThe appliance cannot confirm the pump is moving water. Left alone it becomes an overheat fault, so it is worth acting on promptly.Related: same brand
- E20Stop — call an engineerAlpha call this a flame sensing fault and define it as false flame detection: the appliance can see a flame while the gas valve is shut. Switch it off and call an engineer.Related: same brand
- E38Get it checkedThe burner lit correctly and then the flame signal was lost part-way through the cycle. That points somewhere different to a failure to light.Related: same brand
Own an Alpha boiler? Save it and its codes come first next time.
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.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
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
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.