Vokèra A07 fault codewhat it means and how to fix it
The primary flow sensor is reading out of range or has failed. The appliance stops because it can no longer tell how hot it is running.
Take care
Get a Gas Safe registered engineer to look at your Vokèra A07
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 A07 means
Vokèra word this one carefully in their own documentation: A07 is a primary flow thermistor fault where the temperature of the water is too high. That phrasing is worth noticing, because it does not simply mean the sensor has broken. Vokèra group A07 with A08, the return thermistor equivalent, and both descriptions mention excessive water temperature rather than a dead component.
So on a Vokèra this code sits closer to the overheat family than the pure sensor-failure family, and an engineer who treats it as a straight thermistor swap may well be back a fortnight later. The practical implication is that circulation deserves checking here even though the code names a sensor. If the pump has weakened or the system is airlocked, the water genuinely does get too hot and the thermistor is reporting honestly. Replacing an accurate sensor achieves nothing except a bill.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Water genuinely too hot through poor circulation | Vokèra describe the code in terms of excessive temperature, not just sensor failure. A tired pump or an airlock produces exactly this and the sensor is doing its job. | Common |
| Thermistor drifted out of tolerance | Years of thermal cycling shift the resistance curve until the board no longer trusts it. Measured against the published curve rather than guessed at. | Common |
| Sensor not seated in its pocket | A thermistor that has worked loose reads the air around it, which produces erratic values and often follows earlier work on the appliance. | Occasional |
| Harness chafed against the case | Vokèra appliances are tightly packed and a lead rubbing on a bracket will eventually break down. Cheap to repair if somebody looks for it. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£110–£480
A flow thermistor is typically £110 to £180 fitted. A wiring repair is a call-out charge of £80 to £140. A control board, if it comes to that, is £300 to £480.
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 Vokèra fault codes
- A02Get it checkedThe safety limit thermostat has tripped on overheat. In practice this nearly always means water has stopped circulating properly.Related: overheat and circulation
- A01Get it checkedThe burner failed to light and the appliance has locked out. Check the gas supply and, in cold weather, the condensate pipe before calling anyone.Related: same brand
- A04Usually simple to fixSystem water pressure is below the minimum the appliance will run at. Topping the system back up to 1.2 bar normally clears it straight away.Related: same brand
- 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: same brand
- A11Stop — call an engineerThe appliance is detecting a flame when there should not be one. Turn it off at the fused spur and get a Gas Safe engineer out.Related: same brand
- A09Get it checkedThe flue gas sensor has recorded a temperature above the safe limit, or the sensor itself has failed. Either way the appliance stops.Related: same brand
Own a Vokèra boiler? Save it and its codes come first next time.
Related guides
Common questions about Vokèra A07
Should I let them fit a new thermistor straight away?
Ask them to check circulation first. Vokèra define A07 in terms of the water being too hot, so a healthy sensor reporting a real overheat is a genuine possibility, and a new thermistor will not fix a weak pump.
What is the difference between A07 and A08?
A07 is the primary flow thermistor, on the pipe leaving the heat exchanger. A08 is the return thermistor, on the water coming back, and its third row is the one to watch: Vokèra call it "temperature differential inverted", meaning the return is reading hotter than the flow, and their instruction there is to check the pump and the circulation rather than the sensor. Quote whichever code is on the display, because they are physically different parts in different places. Do not read A10 as a return sensor code — on the ranges that use it, A10 is the ignition lockout.
Does this connect to the A02 overheat lockout?
It can. If circulation has genuinely failed you may see A07 and A02 in the same week, and they are then two symptoms of one problem. Treat the circulation as the fault and the codes as the evidence.
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.