Heatline Vizo Plus 24 Fault codes & diagnostics

26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Natural Gas 24 kW 2007-2009 Discontinued
GC Number 47-157-14

Replaced by: Heatline Capriz

Download the Heatline Vizo Plus 24 manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
26 High

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
47-157-14 Vizo Plus 24 2007–2009

All 26 documented codes

Tap any card for details

10

Your boiler is struggling to detect if water is moving through the system, which is preventing it from heating up your radiators or taps.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Diverter valve diaphragm
  • Wiring harness

Related codes

12

Your boiler's electronic brain is experiencing a critical internal failure and is unable to safely control the system.

High Engineer only £250-400

Parts commonly replaced

  • Main PCB

Related codes

13

Your boiler is struggling to detect the flow of water because it is having trouble reading the internal pressure levels correctly.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Pressure transducer
14

Your boiler is struggling to detect the flow of water because its internal sensor is faulty, which is preventing it from heating your home or water reliably.

High Engineer only £150-250

Parts commonly replaced

  • Flow pressure sensor
  • Wiring harness

Related codes

15

Your boiler is struggling to detect the temperature of your hot water supply, so it has safely stopped heating to prevent potential issues.

High Engineer only £120-200

Parts commonly replaced

  • DHW NTC thermistor sensor
  • Wiring harness

Related codes

16

Your boiler is currently unable to read the water temperature correctly, so it has shut down to prevent overheating while it waits for a repair.

High Engineer only £120-180

Parts commonly replaced

  • Central Heating NTC Sensor

Related codes

17

Your boiler's water circulation device is not moving water effectively, which prevents your heating and hot water from working.

High Engineer only £180-350

Parts commonly replaced

  • Central heating pump
  • Pump head
  • Pump capacitor

Related codes

18

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

High DIY-safe £80-120

What to check first

  1. Locate the filling loop, which is a silver braided hose connected to two valves beneath the boiler.
  2. Open both taps on the filling loop slowly to let water into the system until the pressure gauge reads between 1 and 1.5 bar.
  3. Close both taps tightly and check the boiler display to see if the fault code has cleared.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Pressure sensor
19

Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.

High DIY-safe £80-120

What to check first

  1. Locate the external filling loop (a flexible silver hose pipe) underneath your boiler.
  2. Open the small valve or tap attached to the loop slowly until you hear water entering the system.
  3. Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).
  4. Close the valve tightly and check that the error code has cleared.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Expansion vessel

Related codes

20

Your boiler has detected a critical internal hardware fault with its main electronic control unit, preventing it from operating safely.

High Engineer only £250-450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Wiring harness

Related codes

Showing 11–20 of 26
21

Your boiler has lost the ability to accurately measure the temperature of the water flowing through the system, so it has shut down to prevent damage.

High Engineer only £120-220

Parts commonly replaced

  • NTC thermistor
  • Wiring harness

Related codes

23

Your boiler is not detecting water flowing through its pipes, which means it will stop heating your water or home to prevent damage.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Hall effect sensor
  • Wiring harness
24

Your boiler is failing to detect that water is circulating through the system, so it has shut down to prevent the internal components from overheating.

High Engineer only £120-220

Parts commonly replaced

  • Flow sensor
  • Hall effect sensor
  • Wiring harness

Related codes

25

Your boiler is struggling to accurately measure the water pressure inside the system, which is preventing it from firing up safely.

High Engineer only £120-220

Parts commonly replaced

  • Pressure sensor
  • Wiring harness
26

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

High DIY-safe £80-120

What to check first

  1. Locate the external filling loop, which is usually a flexible metal or braided hose connected to two valves beneath the boiler.
  2. Open both valves slowly to allow water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.
  3. Close both valves tightly and ensure the pressure gauge stays steady.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Pressure sensor
27

Your boiler has detected an issue with the water circulation, meaning it has shut down to prevent internal damage or overheating.

High Engineer only £150-300

Parts commonly replaced

  • Circulation pump
  • Flow sensor
  • System filter

Related codes

600

Your boiler is failing to start up properly after multiple attempts.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

900

Your boiler has detected an electrical issue where it is not receiving the correct voltage required to run its components safely.

High Engineer only £150-300

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Wiring harness
  • Transformer
1000

Your boiler is experiencing a communication error between its internal electronic control systems, which is preventing it from operating correctly.

High Engineer only £150-300

Parts commonly replaced

  • Main printed circuit board (PCB)
  • Wiring harness
F1

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

High Engineer only £120-250

Parts commonly replaced

  • Overheat thermostat
  • Central heating pump
  • Diverter valve
  • PCB

Related codes

Showing 21–26 of 26
F2

Your boiler has stopped producing hot water because it is having trouble reading the temperature of the water as it leaves the tap.

High Engineer only £120-200

Parts commonly replaced

  • DHW NTC thermistor
  • Wiring harness

Related codes

F3

Your boiler's temperature sensor is reporting an error, which has caused the system to shut down for safety to prevent overheating.

High Engineer only £120-200

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring Harness

Related codes

F4

Your boiler has failed to light the flame properly, which has caused it to stop working as a safety precaution.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Condensate trap

Related codes

F5

Your boiler has detected a faulty sensor that monitors the temperature of the exhaust gases, and as a safety precaution, it has shut itself down.

High Engineer only £120-220

Parts commonly replaced

  • Flue gas temperature sensor
  • Wiring harness

Related codes

F8

Your boiler has stopped working because the internal fan responsible for clearing exhaust gases is not spinning at the correct speed.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)
  • Venturi tube

Related codes

F9

Your boiler has detected that the internal exhaust fan is spinning when it should be turned off, which prevents the system from starting safely.

High Engineer only £150-250

Parts commonly replaced

  • Fan assembly
  • Printed Circuit Board (PCB)

Related codes