Buderus 2E 207 Fault Code: Causes, Fixes & Repair Costs
What does the Buderus 2E 207 fault code mean?
The Buderus fault code 2E 207 tells you that water pressure inside your sealed heating system has dropped below 0.2 bar — far too low for the boiler to operate safely. The '2E' part denotes the error class (a blocking fault, meaning the boiler shuts itself down as a safety measure), while '207' is the specific sub-code identifying the low-pressure condition. You'll see this code on models like the Logamax plus GB142 and Logano plus GB402 among others. Until the pressure is restored to the correct level (typically 1–1.5 bar when the system is cold), the boiler will remain locked out and won't produce heat or hot water.
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
- Low system pressure after radiator bleeding or extended shutdown Common
Bleeding radiators releases trapped air but also lets a small amount of water out, which can nudge the system pressure below the 0.2 bar threshold. The same can happen if the boiler has been switched off for a prolonged period and pressure has gradually crept down. This is the most frequent trigger for a 2E 207 code and is straightforward to resolve by topping up via the filling loop.
- Water leak in the heating system Common
A slow drip from a radiator valve, pipe joint, or underfloor heating circuit can cause pressure to drop repeatedly. If you find yourself needing to repressurise more than once every few months, a leak is the most likely culprit. Look for damp patches on floors, ceilings, or around radiator valves. Persistent leaks need a Gas Safe engineer to trace and repair properly.
- Faulty or waterlogged expansion vessel Sometimes
The expansion vessel absorbs pressure changes as the system heats and cools. If its internal diaphragm splits or the pre-charge pressure is lost, the system can no longer buffer these changes correctly — you may notice the pressure gauge swinging wildly or the pressure relief valve (PRV) dripping. When the vessel fails to maintain pressure, the 2E 207 code can appear even if there is no actual water leak.
- Defective pressure sensor or wiring fault Sometimes
The boiler reads system pressure through a sensor (sometimes called a pressure switch or transducer) connected to the PCB. If the sensor itself is faulty, has corroded contacts, or its wiring is loose, it may report falsely low pressure even when the system is correctly pressurised. A Gas Safe engineer can test the sensor and its circuit to confirm whether the reading is genuine or a sensor error.
- PCB (printed circuit board) fault Rare
In rare cases the control board misinterprets signals from the pressure sensor due to component failure, moisture ingress, or burnt tracks. If all physical causes have been ruled out and the 2E 207 code persists after correct repressurisaton, PCB failure becomes a possibility. This is a job for a qualified engineer with the correct diagnostic equipment.
How to fix it
- Check your system pressure gauge DIY safe
Look at the pressure gauge on the boiler's front panel or pipework. If it reads below 1 bar (or is sitting at zero), low pressure is almost certainly the genuine cause of the 2E 207 code rather than a sensor fault. If the gauge reads 1–1.5 bar and the fault is still showing, the issue may lie with the sensor or PCB rather than actual pressure loss — skip to step 5.
- Repressurise the system using the filling loop DIY safe
Locate the filling loop — usually a flexible braided hose with one or two valves beneath the boiler. Slowly open the valve(s) and watch the gauge climb. Stop when it reaches approximately 1.2–1.5 bar, then close the valve(s) firmly. Never overfill beyond 2 bar. If you're unsure where the filling loop is on your specific Buderus model, consult the user section of your manual or look for a label near the boiler pipework.
- Reset the boiler DIY safe
Once pressure is restored, press and hold the Reset button on the boiler's control panel for around 5 seconds (exact location varies by model — check your user guide). The boiler should attempt to restart and the 2E 207 code should clear. Do not reset more than 2–3 times in quick succession; repeated resets without resolving the root cause can mask a more serious problem.
- Bleed your radiators if pressure dropped after bleeding DIY safe
If you recently bled your radiators and the pressure fell as a result, re-check the pressure after bleeding each radiator and top up via the filling loop as needed. Work from the ground floor upwards, and remember to repressurise once all radiators have been bled. After bleeding, re-check the gauge and carry out another reset if required.
- Inspect for visible leaks around the system DIY safe
Walk around your home and check radiator valves, visible pipe joints, and the area around the boiler itself for signs of dripping water, damp patches, or white limescale residue (a sign of a previously weeping joint). If the boiler pressure drops again within a few days of repressurisaton, a leak is highly likely. Do not attempt to repair pipework or internal boiler components yourself — contact a Gas Safe registered engineer.
- Call a Gas Safe registered engineer if the fault persists or returns Gas Safe engineer
If the 2E 207 code returns shortly after you've topped up the pressure, or if the system pressure is already correct but the fault won't clear, there is an underlying problem that a homeowner cannot safely diagnose or fix. An engineer will check the expansion vessel pre-charge pressure, test the pressure sensor and its wiring, inspect for concealed leaks, and assess the PCB if needed. All internal boiler work and any work on the gas supply must be carried out by a Gas Safe registered engineer — it is a legal requirement in the UK.
Parts you may need
- System pressure sensor / transducer · from £35
- Expansion vessel (internal, 8–12 litre) · from £55
- Filling loop assembly · from £20
- Pressure relief valve (PRV) · from £18
- PCB / main control board · from £220
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–£350, depending on the underlying cause.
Frequently asked questions
Can I fix the Buderus 2E 207 fault myself?
If the cause is simply low pressure, yes — topping up via the filling loop is a straightforward homeowner task. Repressurise to around 1.2–1.5 bar, reset the boiler, and it should fire back up. However, if the pressure drops again within days, or if the gauge already shows a normal reading when the fault appears, the underlying cause (a leak, failed expansion vessel, faulty sensor, or PCB issue) requires a Gas Safe registered engineer. Internal boiler repairs are not legal DIY territory in the UK.
Why does my Buderus boiler keep losing pressure and showing 2E 207?
Recurring pressure loss almost always points to either a water leak somewhere in the system or a failed expansion vessel. A leaking radiator valve, a weeping pipe joint, or a split diaphragm inside the expansion vessel are the most common culprits. If you're topping up more than once every couple of months, book a Gas Safe engineer to carry out a full pressure test and expansion vessel check — catching a slow leak early is far cheaper than dealing with water damage later.
What does the 'B 2E 207' display mean on my Buderus boiler?
The 'B' prefix you'll see in some Buderus fault tables (for example in the Logano plus GB402 documentation) stands for 'blocking fault'. This means the boiler has deliberately shut itself down as a safety precaution because the system pressure has fallen below 0.2 bar. The boiler will not restart until the pressure is restored and a reset is performed. The underlying sub-code 207 specifically identifies the low-pressure condition — so B 2E 207 and 2E 207 refer to exactly the same fault.
How much will it cost to fix a Buderus 2E 207 fault?
If a simple top-up of the system pressure resolves it, you may only pay a call-out fee of around £80–£120 if you can't do it yourself. Replacing a faulty pressure sensor typically costs £100–£200 including labour. An expansion vessel replacement usually runs £150–£350 all in. If a pipe or radiator valve is leaking, repair costs depend on location and accessibility but commonly fall in the £120–£300 range. In the unusual situation where the PCB is at fault, expect £250–£450 or more — though this is rare for a 2E 207 specifically.