Remeha E.00.00 Fault Code: Causes, Fixes & Repair Costs
What does the Remeha E.00.00 fault code mean?
E.00.00 is a lockout fault on modern Remeha boilers, most commonly seen on the Quinta Ace, Quinta Pro, Calenta, and Avanta Plus ranges. When a Remeha boiler displays a code beginning with 'E', it has shut itself down completely and will not restart until the fault is cleared and the boiler is manually reset. The '00' fault group points to one of two related problems: either the boiler's Parameter Storage Unit (PSU) cannot locate a required parameter — essentially a configuration or memory fault in the control system — or one of the temperature sensors (flow, return, or boiler sensor) has failed, lost its electrical connection, or developed a short circuit. Both situations prevent the boiler from confirming it is operating safely, so it locks out as a precaution. Remeha's three-tier code system uses 'A' prefix codes for warnings, 'H' prefix codes for blocking faults (temporary shutdowns that clear automatically), and 'E' prefix codes for lockouts that require manual intervention — so E.00.00 represents the most serious tier for this fault category.
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
- Faulty or disconnected temperature sensor Common
The flow, return, or boiler temperature sensor has either failed internally or its wiring connector has worked loose from the PCB or sensor clip. This is the most frequent trigger for an E.00.00 lockout. The return sensor in particular is a small clip-on device attached to the return pipework, sometimes tucked under pipe insulation, and can be dislodged during other work or simply fail with age.
- Damaged sensor wiring Common
The cable running from a temperature sensor back to the PCB may have suffered damage — chafing against pipework, corrosion at a connector, or a partial break in the conductor. Even a high-resistance connection rather than a full break can cause intermittent lockouts before becoming a permanent fault.
- Corrupted or missing PSU parameters Sometimes
The Parameter Storage Unit holds the boiler's configuration data. If a parameter becomes corrupted — due to a power surge, a firmware issue, or the PSU beginning to fail — the boiler cannot find the value it needs and locks out. An engineer will either be able to reprogram the unit or will need to replace the PSU or PCB assembly.
- Incorrectly positioned or poorly fitted sensor Sometimes
If the return temperature sensor clip is not properly seated against the pipework, or has been refitted in the wrong position after a service, the boiler may read implausible temperatures and lock out. This is more likely after recent boiler servicing or pipework alterations.
- PCB fault Rare
In a small number of cases the PCB itself is responsible — either because a component on the board has failed or because the board can no longer communicate correctly with the PSU. This tends to be a diagnosis of exclusion once sensors and wiring have been ruled out.
How to fix it
- Attempt a single manual reset DIY safe
Locate the reset button on the boiler's front panel — on most Remeha models it is a clearly labelled button or a recessed switch. Press and hold it briefly, then allow up to 60 seconds for the boiler to restart. If the boiler fires up and runs normally, monitor it over the next few hours. If it locks out again, do not keep resetting it; repeated resets on a persistent fault can mask the problem and, in some cases, cause additional wear.
- Check system pressure DIY safe
Look at the pressure gauge on the boiler front panel. For most Remeha models, normal operating pressure when cold is 1.0–1.5 bar. If the needle sits below 0.8 bar, the system may need topping up via the filling loop — a flexible braided hose with two isolating valves, usually found beneath the boiler. Slowly open both valves until the gauge reads approximately 1.2–1.3 bar, then close them. Do not overfill above 2.0 bar. Low pressure alone is unlikely to cause an E.00.00 code, but it is worth ruling out before calling an engineer.
- Confirm the gas supply is active DIY safe
Check that other gas appliances in your home — a hob, for example — are working normally. If they are not, contact your gas supplier rather than attempting any boiler work. If the gas supply is fine, the fault is almost certainly internal to the boiler.
- Check whether the condensate pipe is frozen (in cold weather) DIY safe
If outdoor temperatures are at or below freezing and the boiler has a white plastic condensate pipe running outside, that pipe may be frozen solid. You can thaw it by pouring warm (not boiling) water along the pipe or wrapping it in a warm, damp cloth. Once thawed, reset the boiler. Note that a frozen condensate pipe normally produces a different fault code, but it is a quick, safe check worth completing.
- Engineer to inspect temperature sensors and wiring Gas Safe engineer
A Gas Safe registered engineer will visually inspect the flow and return temperature sensors, check that each sensor clip is correctly seated on the pipework, and test the resistance of each sensor with a calibrated multimeter. Sensor resistance values follow a known curve against temperature; a reading outside the expected range confirms a faulty sensor. They will also inspect the wiring looms for damage, corrosion, or loose PCB connectors.
- Engineer to test or replace the PSU / PCB if sensors are sound Gas Safe engineer
If all sensors and wiring test correctly, the engineer will turn attention to the Parameter Storage Unit. On some Remeha models the PSU parameters can be re-uploaded using diagnostic software; on others the PSU or PCB assembly must be replaced. The engineer will source the correct part for your specific boiler model and serial number, fit it, and recommission the boiler — including a flue gas analysis to confirm safe combustion.
- Call a Gas Safe registered engineer Gas Safe engineer
If the boiler has not resumed normal operation after the homeowner checks above, contact a Gas Safe registered engineer. Ask for someone with experience on Remeha commercial or domestic boilers. You can verify any engineer's registration at gassaferegister.co.uk. Do not continue to reset a locked-out boiler or attempt to access internal components yourself.
Parts you may need
- Return temperature sensor (NTC) · from £25
- Flow temperature sensor (NTC) · from £25
- Sensor wiring loom / harness · from £45
- Parameter Storage Unit (PSU) · from £95
- PCB / control board assembly · from £290
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 an E.00.00 fault myself or do I need an engineer?
You can safely attempt one reset using the button on the boiler's front panel. If the boiler fires up and stays running, keep an eye on it over the next day or two. However, if it locks out again — or if it fails to start at all — you should stop resetting and call a Gas Safe registered engineer. The underlying fault will not fix itself, and repeated resets on a persistent lockout can occasionally cause additional stress to components.
How much does it typically cost to fix a Remeha E.00.00 fault?
For the most common cause — a faulty or poorly connected temperature sensor — you can expect to pay roughly £120–£200 in total, covering a call-out, diagnosis, and the sensor itself. If the PSU parameters need reprogramming, costs are similar. A PCB or PSU replacement is less common but significantly more expensive, typically £300–£500 or above once you include parts and labour. If your Remeha boiler is over twelve years old and needs a PCB, it is worth asking your engineer whether a new boiler would be a better investment.
What is the difference between an E, H, and A code on a Remeha boiler?
Remeha's modern control system uses three distinct prefixes. An 'A' code is a warning — the boiler is still running but flagging an issue that should be looked at. An 'H' code is a blocking fault — the boiler has paused operation but will attempt to restart automatically once conditions return to normal. An 'E' code is a full lockout — the boiler has shut down completely and will not restart until someone presses the reset button, and the underlying fault is resolved. E.00.00 is therefore the most serious category and warrants prompt attention.
Could E.00.00 appear after a power cut or surge?
Yes. A sudden loss of power or a voltage spike can occasionally corrupt the data stored in the boiler's Parameter Storage Unit, triggering an E.00.00 lockout when the boiler tries to read a parameter that is no longer intact. A single reset after a power cut is always worth trying. If the boiler runs normally afterwards, no further action may be needed. If it continues to lock out, an engineer will need to check whether the PSU data can be restored or whether the unit needs replacing.