Intergas 9 Fault Code: Causes, Fixes & Repair Costs
What does the Intergas 9 fault code mean?
Fault code 9 on an Intergas boiler signals that the burner controller — the electronic board responsible for managing the ignition sequence, gas valve operation, and flame control — has detected an internal fault within itself. When this code appears, the boiler's operating panel or service display will typically flash to alert you. If multiple faults are present simultaneously, the temperature display may show an additional sub-code alongside the flashing. Because the burner controller is essentially the decision-making centre of the boiler, a fault here can bring the entire heating and hot water process to a halt. This is one of the more serious Intergas fault codes and almost always requires professional diagnosis and, in most cases, replacement of the burner controller PCB by a Gas Safe registered engineer.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Internal component failure on the PCB Common
Over time, individual components on the burner controller board — capacitors, relays, or solder joints — can degrade and fail. Because the board is constantly cycling through ignition sequences and monitoring the flame, wear is inevitable. This is the most common reason fault code 9 appears on older Intergas boilers.
- Electrical fault or power surge Common
A sudden spike in the mains supply — whether from a storm, a power cut, or a grid fluctuation — can damage sensitive electronics on the burner controller. The board may still partially function, making the fault intermittent at first before becoming permanent.
- Water ingress or internal corrosion Sometimes
If a nearby component such as the heat exchanger or a pipe joint has been leaking, moisture can reach the PCB over time. Corrosion on the board's connectors or tracks can disrupt the signals the controller sends to the gas valve and ignition system, triggering a fault 9.
- Wiring fault between the PCB and gas valve Sometimes
A loose, damaged, or corroded wiring harness between the burner controller and the gas valve can cause the board to detect an unexpected electrical state and flag an internal fault. The board itself may be undamaged, making this worth checking before a full replacement.
- Age-related board degradation Rare
Boilers over ten years old may develop fault code 9 simply because the burner controller has reached the end of its serviceable life. What often starts as occasional lockouts or a flickering display gradually progresses to a hard fault that prevents operation entirely.
How to fix it
- Check whether the boiler has power and reset it once DIY safe
Before assuming the worst, confirm the boiler is receiving power and press the reset button as described in your Intergas manual. A single reset can clear a transient electrical glitch. Do not reset more than two or three times — repeated resets without a successful restart will not fix a genuine PCB fault and can mask the problem from an engineer.
- Check your home's gas supply is active DIY safe
Make sure other gas appliances such as a hob or gas fire are working normally. If there is no gas elsewhere in the property, contact your gas supplier rather than an engineer, as the issue is upstream of the boiler entirely.
- Check the system pressure is between 1 and 1.5 bar DIY safe
A very low system pressure can sometimes cause unexpected lockouts. Look at the pressure gauge on the front of the boiler — if it reads below 1 bar, top up via the filling loop as described in your Intergas manual. This is unlikely to resolve a fault code 9 but rules out a secondary issue.
- Do not open the boiler casing or touch any internal components Gas Safe engineer
The burner controller PCB is located inside the boiler casing. Removing panels, disconnecting wiring, or attempting to inspect or replace the board yourself is dangerous and illegal for gas-related components. It will also invalidate your warranty. Leave all internal investigation to a qualified engineer.
- Call a Gas Safe registered engineer to diagnose the fault Gas Safe engineer
A Gas Safe engineer will open the casing safely, inspect the burner controller and its wiring harness, and use Intergas diagnostic tools to confirm whether the fault lies in the board itself, a wiring connection, or a related component. They will advise whether a repair or full PCB replacement is needed. Ask them to check whether the boiler is still within its Intergas warranty period (which can extend from 3 to 10 years depending on the model and registration), as this may cover the cost of the part.
Parts you may need
- Intergas Burner Controller PCB (e.g. part 074447) · from £95
- Wiring harness / loom (gas valve to PCB) · from £35
- Gas valve (if damaged by electrical fault) · from £120
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £300–£550, depending on the underlying cause.
Frequently asked questions
Can I reset my Intergas boiler to clear fault code 9?
You can try a single reset — it occasionally clears a one-off electrical glitch. However, fault code 9 specifically indicates the burner controller has detected an internal fault within itself, so a reset is unlikely to resolve the underlying issue. If the code returns immediately or persists after one or two resets, stop resetting and call a Gas Safe engineer. Repeatedly resetting a boiler with a genuine PCB fault will not fix it.
How much does it cost to replace an Intergas burner controller PCB in the UK?
The PCB part itself typically costs between £75 and £115 from UK spare parts suppliers. Adding a Gas Safe engineer's labour — usually one to three hours of work — and a diagnostic call-out fee, most homeowners pay between £300 and £550 all-in for this repair in 2025. Costs tend to be higher in London and the South East. If your boiler is still within its Intergas manufacturer warranty (which can be up to 10 years on some registered models), the part may be covered, significantly reducing your outlay. Note that on very old boilers or where additional components were damaged by a power surge, costs could be higher — ask your engineer for a written quote before work begins.
Is fault code 9 covered by the Intergas warranty?
It can be. Intergas boilers come with a standard 12-month warranty, which can extend to 3, 5, or even 10 years on certain models if the boiler was registered and has been serviced annually by a Gas Safe engineer. If your boiler is still within this period, contact Intergas or your installer before booking an independent engineer, as an approved repair may be arranged at no or reduced cost to you.
Should I replace my boiler instead of repairing the PCB?
If your Intergas boiler is less than 8 to 10 years old and has otherwise been reliable, a PCB replacement is usually the more cost-effective choice. However, if the boiler is over 10 years old, has had multiple faults in recent years, or the repair quote approaches or exceeds around £600, it is worth getting quotes for a new boiler at the same time. Modern A-rated condensing combi boilers can significantly reduce your energy bills, and many installers will offset the repair quote against a new installation if you decide to upgrade.