Baxi E.02-.17 Fault Code: Causes, Fixes & Repair Costs
What does the Baxi E.02-.17 fault code mean?
The E.02-.17 code indicates a permanent, locking communication breakdown between the boiler's gas valve and its PCB (Printed Circuit Board). Because the PCB can no longer reliably send or receive signals to and from the gas valve, the boiler shuts itself down and will not attempt to restart on its own — it stays locked out until an engineer diagnoses and resolves the underlying fault. This is the permanent version of the related H.01.00 code, which flags only a temporary communication hiccup that can sometimes clear itself. E.02-.17 will not clear on its own and is not safe to keep resetting without identifying the root cause.
General guidance only — not a substitute for professional advice. 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
- Loose or corroded wiring connection to the gas valve Common
The most frequent trigger. A connector pin that has worked loose, a terminal affected by corrosion, or a wire that has been pinched or chafed can interrupt the communication signal between the gas valve and the PCB. These wiring issues are common on boilers that are several years old or have been disturbed during a previous service.
- Faulty gas valve Common
The gas valve contains its own electronic components that receive instructions from the PCB. If the valve's internal electronics fail — due to age, moisture ingress, or a power surge — the communication link drops permanently and the E.02-.17 code is triggered. The valve will need to be replaced rather than repaired.
- Failed or damaged PCB Sometimes
The PCB is effectively the boiler's control centre, sending commands to every component including the gas valve. If the PCB develops a fault on the circuit that handles gas valve communication — through component failure, moisture damage, or electrical surge — it can produce this code even when the valve and wiring are intact.
- Fault in the air/gas unit Sometimes
On some Baxi models the gas valve is integrated with or closely coupled to an air/gas assembly. A mechanical or electronic fault within that combined unit can disrupt communication signals and log the E.02-.17 error, even if the standalone wiring and PCB appear healthy.
How to fix it
- Switch the boiler off at the programmer or room thermostat and note the fault code displayed DIY safe
Before anything else, write down the exact code shown (E.02-.17) and the time it appeared. This information helps an engineer establish whether the fault is consistent or intermittent. Do not open the boiler casing or attempt to inspect internal components yourself.
- Check that your gas supply is working DIY safe
Confirm that other gas appliances in your home — such as a gas hob or gas fire — are operating normally. If none of your gas appliances are working, the fault may lie with your gas supply rather than the boiler. Contact your gas supplier if you suspect a supply issue.
- Attempt a single boiler reset DIY safe
Follow the reset procedure in your Baxi user manual (typically pressing and holding the reset button for a few seconds). If the boiler fires up and runs normally, monitor it closely over the next hour or two. If the E.02-.17 code returns, do not continue resetting — repeated resets without a confirmed fix are not appropriate for a permanent locking fault and will not resolve the underlying problem.
- Do not open the boiler casing or handle any internal components Gas Safe engineer
Inspecting or replacing the gas valve, PCB, or wiring connections inside the boiler is work that must only be carried out by a Gas Safe registered engineer. Attempting this yourself is both illegal for gas-related work and potentially dangerous.
- Have a Gas Safe registered engineer inspect all wiring between the gas valve and PCB Gas Safe engineer
An engineer will check every connector, terminal, and length of cable in the gas valve communication circuit. Loose pins will be reseated, corroded terminals cleaned or replaced, and damaged wiring sections renewed. This is often the quickest and least expensive fix if the fault is wiring-related.
- Have the engineer test and if necessary replace the gas valve Gas Safe engineer
If the wiring checks out, the engineer will electrically test the gas valve to determine whether its internal electronics have failed. A faulty valve on a Baxi boiler will need to be swapped for a manufacturer-approved replacement part before the boiler can safely operate again.
- Have the engineer test or replace the PCB if the valve and wiring are sound Gas Safe engineer
Should both the wiring and the gas valve test as healthy, the PCB becomes the prime suspect. The engineer may be able to carry out component-level testing to isolate the fault, but in many cases a full PCB replacement is the most reliable resolution. Check your boiler warranty first — Baxi offers up to 10 years' cover on qualifying installations serviced annually, and a PCB replacement may be included.
- Arrange for a Gas Safe registered engineer if the fault persists or recurs Gas Safe engineer
If you haven't already called an engineer, or if the fault returns after a repair, contact a Gas Safe registered heating engineer to carry out a full diagnostic. You can verify an engineer's registration at gassaferegister.co.uk.
Parts you may need
- Baxi gas valve (model-specific) · from £130
- Baxi PCB (main circuit board, model-specific) · from £220
- Gas valve wiring harness / loom · from £35
- Gas valve connector/terminal repair kit · from £12
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 £120–£380, depending on the underlying cause.
Frequently asked questions
Can I reset my Baxi boiler myself when E.02-.17 appears?
You can try a single reset following the instructions in your Baxi user manual, but because E.02-.17 is classified as a permanent locking fault it is very unlikely to clear without a physical repair. If the code returns after one reset, stop resetting and call a Gas Safe registered engineer — repeated resets will not fix the underlying communication fault and could mask a developing problem.
What is the difference between E.02-.17 and H.01.00 on a Baxi boiler?
Both codes relate to communication between the gas valve and the PCB, but they behave very differently. H.01.00 is a temporary communication fault that may resolve itself and allow the boiler to restart normally. E.02-.17 is the permanent version — the boiler locks out completely and will not restart until an engineer investigates and repairs the root cause. If you are seeing E.02-.17 rather than H.01.00, engineer attendance is always required.
How much does it cost to fix a Baxi E.02-.17 fault in the UK?
The most common repair — tracing and rectifying a loose or damaged wiring connection — typically costs £120 to £180 including call-out and labour. Replacing the gas valve usually brings the total to around £250 to £380 once parts and labour are included. A PCB replacement is less common for this fault but is significantly more expensive, often £450 to £700 in total; if your engineer suspects the PCB is at fault, always check your Baxi warranty first as it may be covered. Engineers may also charge a diagnostic fee of around £60 to £100 to confirm the fault before proceeding with the repair.
Is my Baxi boiler still under warranty if I have an E.02-.17 fault?
All new Baxi boilers come with at least a 2-year parts and labour warranty, and this can extend to up to 10 years on qualifying models when installed by a Baxi-accredited engineer and serviced annually. If your boiler is within its warranty period and has been serviced every year by a Gas Safe registered engineer, the cost of replacing a faulty gas valve or PCB may be covered. Check your warranty documentation or contact Baxi directly before authorising any paid repair.