Overview
The Baxi EcoBlue error 432 indicates a fault with the boiler's earth/ground connection (an "earth connector error"). In short, the boiler's safety electronics have detected an electrical earthing problem — either a poor earth connection, an earth leakage, or a loss of protective grounding. Because the earth is part of the boiler's safety system, the appliance will often lock out or inhibit operation to prevent electric shock, damage to electronics (PCB), or further unsafe operation. This is a potentially serious electrical fault. It is not a normal simple water-pressure or ignition issue and should be treated conservatively. Some temporary causes (e.g. a loose external connection or a tripped RCD/MCB) can be corrected by straightforward checks and a reset, but any persistent 432 fault, signs of burning, moisture inside the boiler, repeated lockouts or uncertainty about wiring requires a qualified engineer. Do not attempt internal electrical repairs unless you are a competent, Gas Safe registered engineer and a qualified electrician for the electrical earthing work.
Possible Cause: Earth connector error
Troubleshooting Steps
Safety first:
- If you smell gas, evacuate the property immediately and call the gas emergency number. Do not operate switches or the boiler.
- Turn the boiler off at the control panel and isolate electrical supply at the boiler isolator or the consumer unit before touching anything. If you are unsure which isolator controls the boiler, turn off the circuit at the consumer unit (fuse box).
- Do not open sealed/locked or live electrical compartments inside the boiler unless you are a qualified engineer. Avoid touching internal wiring or PCB components.
Initial homeowner checks (safe, non-invasive):
1. Note the exact error code and any other symptoms (no heating/hot water, display behaviour, smell, unusual noises). Take a photo of the display showing 432 and the boiler model.
2. Try a standard reset: with the boiler powered, press and hold the reset button (or selector to R) for 5–10 seconds and see if the boiler attempts to restart. If the code clears and the boiler runs normally, monitor it — do not keep repeatedly resetting if it returns.
3. Check the consumer unit (fuse box) for tripped RCD/MCB or a blown fuse protecting the boiler circuit. If a breaker has tripped, switch it fully off then on again and then try restarting the boiler once power is restored.
4. Check any visible external wiring (not inside the boiler) for obvious damage or loose connections where the supply enters the boiler or at the external isolator switch. Do not touch live wires; isolate power first.
5. If there has been recent electrical work, plumbing work, or lightning/surge, note this — it can have introduced earthing or leakage problems.
What a qualified engineer or electrician will do (do not attempt unless qualified):
- Verify electrical isolation and then inspect the boiler's earth/ground connection and bonding points for secure mechanical and electrical contact.
- Measure earth continuity and insulation resistance to detect leakage, high resistance or an open earth.
- Check external earthing and main incoming protective earth at the consumer unit and any local bonding to gas and water pipes.
- Inspect the boiler for signs of water ingress, corrosion or burnt components on the PCB and replace/repair as required.
- Replace or reterminate the earth connector/earthing strap if it is corroded, damaged or loose.
- Test RCD/MCB operation and check for residual current faults that could indicate a problem elsewhere on the circuit.
Recommended next steps for you to get the fault resolved:
- If the reset fails or the 432 code returns, leave the boiler isolated and contact a Gas Safe registered heating engineer. Tell them the boiler model, that it is showing error 432 (earth connector error), and what checks you have already done.
- Because this is an electrical earthing fault, consider arranging a qualified electrician to attend alongside the Gas Safe engineer or ensure the heating engineer is competent to test and repair earthing/bonding.
- Do not operate the boiler if the error persists, if you smell burning, see scorch marks, or notice corrosion/moisture inside the casing.
Final note: an earth connector error is a safety-related fault. Some simple checks are safe for a homeowner, but diagnosis and any repair to the earthing system, internal wiring, PCB or bonded connections must be carried out by suitably qualified professionals. Repeatedly resetting the boiler without fixing the underlying earthing fault is unsafe and not advised.
Helpful Resources
Boiler Manual
Download the official PDF manual for the Baxi EcoBlue.