Warmflow Agentis Boilerhouse Fault codes & diagnostics

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

Heat Only Oil 2018-present
Download the Warmflow Agentis Boilerhouse manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
1 Emergency 11 High 1 Medium 1 Low
Just want the most common Warmflow Agentis Boilerhouse faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 14 documented codes

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E01

Your boiler has stopped running because it failed to light, likely due to a problem with the oil supply or a burner fault.

High DIY-safe £120-350

What to check first

  1. Check that your heating oil tank actually has fuel in it
  2. Ensure the oil supply valve from the tank is fully open
  3. Press the illuminated reset button on the front of the burner once

Parts commonly replaced

  • Oil nozzle
  • Oil pump
  • Photocell
  • Fuel filter

Related codes

Full explanation for E01
E02

Your boiler has switched itself off because it has reached an unsafe temperature to prevent internal damage.

High Engineer only £120-£350

Parts commonly replaced

  • Limit Thermostat
  • Circulation Pump
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E02
E04

Your boiler has detected that there is not enough water pressure in the pipes to operate safely.

High DIY-safe £60-180

What to check first

  1. Check the pressure gauge on the boiler or expansion vessel; it should be between 1.0 and 1.5 bar.
  2. Locate the external filling loop and slowly open the valves to top up the system with water until the gauge reaches 1.2 bar.
  3. Ensure both valves on the filling loop are closed tightly and reset the boiler.

Parts commonly replaced

  • Filling loop
  • Expansion vessel
  • Pressure relief valve

Related codes

Full explanation for E04
E05

Your boiler has lost its ability to monitor the temperature of the water leaving the unit, meaning it cannot operate safely and has shut down.

High Engineer only £90-160

Parts commonly replaced

  • Flow NTC Temperature Sensor
  • Sensor Wiring Harness

Related codes

Full explanation for E05
E06

Your boiler has detected a problem with the sensor that monitors the temperature of your hot water, meaning it cannot safely provide hot water to your taps.

High Engineer only £90-160

Parts commonly replaced

  • DHW Flow NTC Sensor
  • Sensor Wiring Harness

Related codes

Full explanation for E06
E11

Your boiler's hot water tank sensor has moved out of position or failed, meaning the system can no longer accurately monitor the water temperature.

Medium Engineer only £90-160

Parts commonly replaced

  • NTC Temperature Sensor Probe
  • Sensor Clip/Housing

Related codes

Full explanation for E11
E12

Your boiler's hot water temperature sensor has developed a fault or become disconnected, meaning the system can no longer monitor the water temperature accurately.

High Engineer only £90-180

Parts commonly replaced

  • Tank Control NTC Sensor
  • Sensor Wiring Harness

Related codes

Full explanation for E12
E15

Your boiler has detected a fault with the sensor that monitors the temperature of the water returning from your radiators.

Low Engineer only £90-160

Parts commonly replaced

  • CH Return NTC Sensor
  • Wiring Harness

Related codes

Full explanation for E15
E22

Your boiler's internal computer has suffered a software memory error and can no longer process instructions safely.

High Engineer only £250-£450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)

Related codes

Full explanation for E22
E31

Your boiler is having trouble talking to the control panel or thermostat, meaning it cannot receive the instructions it needs to provide heating and hot water.

High Engineer only £120-£350

Parts commonly replaced

  • Remote Control Panel
  • Communication Cable
  • Main PCB

Related codes

Full explanation for E31
E32

Your boiler's main internal computer has lost communication with its control panel, meaning it can no longer send or receive the correct signals to run properly.

High Engineer only £250-£550

Parts commonly replaced

  • Main Control PCB
  • MMI Display PCB
  • Communication Ribbon Cable

Related codes

Full explanation for E32
E46

Your boiler has lost its ability to monitor water pressure because the internal sensor is either broken or not communicating properly.

High Engineer only £120-190

Parts commonly replaced

  • Water Pressure Sensor
  • Sensor Wiring Harness

Related codes

Full explanation for E46
E48

Your boiler has detected that there is too much water pressure in the system, which is preventing it from running safely.

Emergency DIY-safe £0-120

What to check first

  1. Check that the silver braided filling loop valves are tightly closed.
  2. Locate a radiator and use a bleed key to carefully release some water into a container.
  3. Monitor the pressure gauge on the boiler until it returns to the 'green' zone (typically 1.0 to 1.5 bar).
  4. Once the pressure is corrected, reset the boiler.

Parts commonly replaced

  • Filling loop valve
  • Expansion vessel
  • Pressure relief valve

Related codes

Full explanation for E48
E62

Your boiler's main internal computer and its control panel are having trouble talking to each other, which has locked the system for safety.

High Engineer only £250-550

Parts commonly replaced

  • Main Control PCB
  • MMI Display Board
  • Communication Ribbon Cable

Related codes

Full explanation for E62
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