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Ravenheat Fault Code 01 – Ignition Failure

Fault code 01 on a Ravenheat boiler indicates that the boiler attempted to light the main burner but could not establish or confirm a stable flame within its allowed ignition attempts. The PCB detects no valid flame signal and puts the boiler into a safety lockout, cutting off both central heating and hot water until the underlying problem is resolved and the boiler is reset.

lockout May need a Gas Safe engineer 5 models affected

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.

What does the Ravenheat 01 fault code mean?

Fault code 01 on a Ravenheat boiler indicates that the boiler attempted to light the main burner but could not establish or confirm a stable flame within its allowed ignition attempts. The PCB detects no valid flame signal and puts the boiler into a safety lockout, cutting off both central heating and hot water until the underlying problem is resolved and the boiler is reset.

Common causes

How to fix it

  1. Reset the boiler DIY safe

    Press and hold the reset button for approximately five seconds, or use the mains on/off switch on your specific model. The boiler will run through its ignition sequence again. If it locks out immediately and repeatedly, do not attempt more than two or three resets — persistent cycling without a successful ignition can indicate a more serious underlying fault and should not be masked by repeated resets.

  2. Check that your gas supply is working DIY safe

    Confirm that other gas appliances in your home — a gas hob, for example — are working normally. If nothing gas-powered is functioning, contact your gas supplier rather than an engineer, as the issue lies outside your boiler. If only the boiler is affected, the gas supply to the boiler itself is the next thing an engineer should verify.

  3. Inspect and thaw the condensate pipe if the weather is cold DIY safe

    Locate the white or grey plastic pipe that exits the boiler casing and runs to an external drain or soakaway. If outdoor temperatures have been at or below freezing, this pipe may be blocked with ice. Carefully pour warm (not boiling) water along the frozen section until you hear water flowing freely. Once thawed, reset the boiler. If the fault clears, consider insulating the pipe to prevent recurrence.

  4. Have a Gas Safe engineer inspect the flame detection electrode Gas Safe engineer

    A registered engineer will isolate the appliance, remove the front panel, and inspect the electrode for carbon fouling, limescale deposits, or physical damage. In many cases a clean with fine abrasive paper restores conductivity. If the electrode is bent out of position or beyond cleaning, it is an inexpensive part to replace (around £20–£30 for the component) and the repair is usually straightforward.

  5. Have a Gas Safe engineer test the ignition leads and spark generator Gas Safe engineer

    Using electrical test equipment, an engineer can measure whether the spark generator is producing the correct output and whether the ignition lead is carrying that signal to the electrode without loss. Damaged leads or a weak generator will need to be replaced before reliable ignition can be restored.

  6. Have a Gas Safe engineer check gas valve operation and supply pressure Gas Safe engineer

    The engineer will verify that the gas valve is opening correctly when commanded by the PCB and that the dynamic gas pressure at the boiler is within the manufacturer's specified range. A faulty valve or regulator will require replacement by a qualified professional — this work must never be attempted by an unregistered person.

  7. If all components test satisfactory, have the PCB evaluated Gas Safe engineer

    Where the ignition system and gas supply are both confirmed to be working correctly, the fault may lie with the PCB itself. An engineer can carry out further electrical diagnostics to determine whether the board is processing signals correctly. PCB replacement is a significant cost, so obtaining a clear diagnosis before committing to this repair is important.

  8. Call a Gas Safe registered engineer if the fault persists after your DIY checks Gas Safe engineer

    If resetting the boiler and addressing any frozen condensate pipe has not resolved code 01, the fault requires professional diagnosis. Contact a Gas Safe registered engineer and quote the fault code — this will help them arrive prepared with likely replacement parts. You can verify any engineer's registration at gassaferegister.co.uk.

Parts you may need

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–£350, depending on the underlying cause.

Frequently asked questions

Can I keep resetting my Ravenheat boiler showing code 01?

You can try two or three resets to see whether the fault clears — this is sometimes enough if the cause was a temporary glitch or a recently thawed condensate pipe. However, repeatedly resetting a boiler that keeps locking out is not advisable. Each failed ignition attempt means gas is briefly released without being lit, and masking an underlying fault delays a proper repair. If the boiler does not fire successfully after a couple of resets, stop and call a Gas Safe engineer.

My condensate pipe is clear and the boiler still shows fault 01 — what next?

If the condensate pipe is confirmed clear and a reset does not resolve code 01, the most likely causes shift towards the flame detection electrode (dirty or damaged), the ignition lead, or the spark generator. These are all components that need to be inspected and tested by a Gas Safe registered engineer with appropriate electrical test equipment. It is worth mentioning the fault code when you book, so the engineer can bring common replacement parts.

How much does it typically cost to fix a Ravenheat code 01 fault?

For the most common repairs — cleaning or replacing the flame detection electrode, or replacing an ignition lead or spark generator — expect to pay roughly £120 to £350 including labour. A gas valve replacement tends to sit at the higher end of that range. In rarer cases where the PCB is at fault, costs can rise considerably further, sometimes exceeding £400–£500 for parts and labour. For Ravenheat boilers that are over ten years old, it is worth getting a boiler replacement quote alongside any repair quote, as ongoing repairs on an ageing appliance can quickly become uneconomical.

Is fault code 01 dangerous?

A boiler in lockout has shut itself down as a safety precaution, so the immediate risk is low — you lose heating and hot water rather than being exposed to gas. However, you should not attempt to bypass the lockout or interfere with gas components. If you smell gas at any point, do not attempt a reset: leave the property, avoid operating any switches, and call the National Gas Emergency Service on 0800 111 999 immediately.

Affected models: Ravenheat RSF 82ET, Ravenheat RSF 100ET, Ravenheat LS 80, Ravenheat CSI 85, Ravenheat CSI 120

Last reviewed 30 June 2026 · verified by our team.

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