Ravenheat E02 Fault Code: Causes, Fixes & Repair Costs
What does the Ravenheat E02 fault code mean?
The E02 code on a Ravenheat boiler signals a pump circulation fault. The boiler's controls have detected that water is not moving adequately through the primary circuit — either because the pump has stopped, is turning too slowly, or is being obstructed. To prevent overheating and heat-exchanger damage, the boiler shuts itself down until the issue is resolved. On some Ravenheat models (particularly the CS 80/90, WH System, and WH 80/90 ranges) the same fault may appear as 02E rather than E02 — both mean exactly the same thing and the same diagnostic steps apply.
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
- Airlock in the pump or primary circuit Common
Air trapped inside the pump impeller or pipework prevents the pump from generating adequate flow. This is particularly common after recent radiator bleeding, refilling the system, or if the boiler has been dormant over summer. The blockage is usually temporary and can sometimes be cleared without an engineer.
- Pump seizure from sludge or scale Common
Over time, untreated central heating water deposits magnetite sludge and limescale onto the pump impeller and bearings, eventually causing them to seize. Older Ravenheat boilers — especially the WH90 — are frequently affected by this, and hard-water areas accelerate the problem. A seized pump will hum but not spin.
- Worn or failed pump bearings Sometimes
Even without heavy sludge, pump bearings naturally wear with age. A pump that has been running for ten or more years may have bearings that can no longer support smooth rotation, causing the impeller to drag or stop altogether. The pump may make a grinding or rattling noise before failure.
- Pump capacitor failure Sometimes
The start capacitor in the pump motor assists with initial rotation. If it degrades or fails, the motor receives insufficient starting torque and the pump either hums without spinning or does not start at all. This is an electrical component failure rather than a mechanical one.
- Incorrect pump orientation Rare
The pump shaft must be horizontal, with the bleed screw positioned at the side. If a pump has been installed in the wrong orientation — for example with the shaft vertical — bearing wear is significantly accelerated and premature failure follows.
How to fix it
- Check system pressure and top up if needed DIY safe
Look at the pressure gauge on the boiler fascia. If it reads below 1 bar, the system may be too low for the pump to circulate properly. Use the filling loop to raise pressure to between 1 and 1.5 bar, then close the loop valves securely. Low pressure alone can trigger circulation faults.
- Attempt a boiler reset DIY safe
Once pressure is confirmed at 1–1.5 bar, press the reset button (or hold the relevant button as described in your user manual) to clear the lockout. Give the boiler a minute to run through its start sequence and observe whether it fires and heats normally. If the E02 code returns quickly, the underlying fault has not been resolved — do not reset more than two or three times in succession.
- Bleed the pump to release an airlock DIY safe
Turn the boiler off at the programmer and isolate power at the spur. Locate the pump — usually a cylindrical unit near the centre of the boiler — and find its manual bleed screw on the side of the pump head. Place a cloth underneath, then slowly open the bleed screw a quarter-turn. You should hear a brief hiss of air followed by a trickle of water; once only water flows, close the screw. Top pressure back up to 1–1.5 bar via the filling loop, restore power, and reset the boiler. This step is safe for a confident homeowner.
- Attempt to free a seized pump shaft (with caution) DIY safe
With power fully isolated at the spur switch, locate the slotted end of the pump shaft — visible once the bleed screw area is accessible. Insert a flat-blade screwdriver into the slot and try to rotate the shaft gently clockwise. If it is stiff, do not force it. A small amount of penetrating oil applied carefully and left for 10–15 minutes may allow the shaft to free up. This is a temporary measure; if the pump has seized from sludge or bearing wear, it will seize again and a replacement will be needed.
- Call a Gas Safe registered engineer to inspect and replace the pump Gas Safe engineer
If the boiler continues to display E02 after bleeding and a reset, or if the pump shaft could not be freed, a Gas Safe registered engineer should inspect the pump. They will test the pump electrically (including the capacitor), assess the condition of the impeller and bearings, and either service or replace the unit. They will also check whether a system powerflush is needed to remove the sludge that caused the seizure, preventing a repeat failure.
Parts you may need
- Circulator pump (replacement) · from £85
- Pump start capacitor · from £8
- Pump bleed screw · from £4
- Magnetic system filter (fitted to prevent recurrence) · from £55
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 £150–£320, depending on the underlying cause.
Frequently asked questions
Can I fix the Ravenheat E02 fault myself?
The two homeowner-safe steps — bleeding the pump to release an airlock and gently attempting to free a stiff pump shaft — are worth trying before calling an engineer. However, if these do not clear the fault, or if the pump is seized solid, the repair requires a Gas Safe registered engineer. Replacing the pump or capacitor, and any associated pipework work, must be carried out by a qualified professional.
How much does it cost to repair a Ravenheat E02 fault in the UK?
If the fix is a new circulator pump fitted by an engineer, expect to pay roughly £150–£320 including parts and labour — pump replacement on its own typically comes in at around £200–£250 all-in. A failed start capacitor is much cheaper at around £5–£10 for the part, though you will still pay a call-out fee. If the boiler also needs a powerflush to clear the sludge that caused the seizure, add a further £300–£500 depending on system size. On older Ravenheat boilers (over 10–12 years old) it is worth getting a quote for a full boiler replacement alongside the repair cost, as investing heavily in an ageing boiler may not represent good value.
Why does my Ravenheat show 02E instead of E02?
They are the same fault. Ravenheat uses both display formats across its range — E02 appears on some models and 02E on others, including the CS 80/90, WH System, and WH 80/90 series. The meaning and the diagnostic approach are identical: a pump circulation problem that needs to be investigated.
How long should a circulator pump last on a Ravenheat boiler?
A correctly installed pump in a clean system typically lasts 10–20 years. Pumps fail earlier when the central heating water contains high levels of sludge or limescale, when the pump has been installed in an incorrect orientation (shaft should be horizontal), or when the system has never had an inhibitor added. Fitting a magnetic filter and using a quality corrosion inhibitor significantly extends pump life and reduces the chance of an E02 fault recurring.