Ravenheat ERR Fault Code: Causes, Fixes & Repair Costs
What does the Ravenheat ERR fault code mean?
When a Ravenheat boiler simply shows ERR on its display, the fault lies with the user interface itself — the display/control panel has failed its own checks or lost proper communication with the main control board. Unlike a numbered fault, ERR is not telling you about a sensor, the fan or ignition: it is the boiler saying its front-end electronics cannot be trusted. Depending on where the failure sits the boiler may keep heating in the background or may stop, but either way you have lost reliable control and information at the panel. The repair is electronic — connections between the display and the main PCB, the display unit, or occasionally the board behind it.
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
- Display-to-board connection fault Common
The ribbon or plug linking the user interface to the main PCB can loosen or oxidise, interrupting communication. The panel then blanks, scrambles or shows ERR. Reseating the connection — inside the casing, so an engineer job — often cures it.
- Failed display/interface unit Sometimes
The interface module itself can fail with age or after a mains spike: dead segments, unresponsive buttons and the ERR state. A replacement interface restores control.
- Mains supply disturbance Sometimes
A brownout or spike can lock the interface electronics in a fault state even though nothing has physically failed. A full power-cycle at the fused spur clears this case — if ERR returns, the hardware is genuinely at fault.
- Main PCB fault Rare
Least often, the communication failure originates on the main board rather than the panel. Diagnosed by substitution once the interface and connections are ruled out.
How to fix it
- Power-cycle the boiler at the fused spur DIY safe
Switch off for a full minute, then back on. This reboots the interface electronics and clears the lock-up cases caused by supply disturbances. It is the single most effective safe step for ERR.
- Check whether heating still runs DIY safe
Note whether radiators or hot water still work with ERR displayed — it tells the engineer whether the failure is confined to the panel or has taken out control entirely.
- Do not open the casing to check connections Gas Safe engineer
The display loom and PCB are behind the sealed case with live 230 V present. Reseating connections is quick for a Gas Safe registered engineer and not a DIY task.
- Engineer: reseat the interface connection, then substitute parts Gas Safe engineer
The engineer will reseat and inspect the display link, then test or substitute the interface unit, and only lastly the main PCB. After repair they should confirm the panel controls and displays respond correctly through a full heating and hot water cycle.
Parts you may need
- Display / user interface unit · from £90
- Interface ribbon/loom · from £25
- Main control PCB · from £170
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 £100–£280, depending on the underlying cause.
Frequently asked questions
My Ravenheat just says ERR — what does that mean?
The user interface (the display and buttons) has failed its own checks or lost communication with the main board. It is an electronics fault at the panel rather than a heating fault as such. Power-cycle the boiler at the spur once; if ERR returns, the display link, the interface unit or occasionally the main board needs professional attention.
Can I still use the boiler with ERR showing?
Sometimes the boiler carries on heating with the panel out of action, but you have lost reliable control and any further fault would not display properly. Treat it as needing prompt repair, and if the boiler is also not heating, book sooner.
Is ERR expensive to fix?
Usually not: a reseated connection is minimal, a replacement interface unit is a modest part, and only a main-board failure pushes the job toward the top of the £100–£280 range. Get a written quote from a Gas Safe registered engineer.