Ravenheat E46 Fault Code – Water Pressure Sensor Error
The E46 code on a Ravenheat boiler signals that the PCB is receiving an incorrect, absent, or out-of-range signal from the water pressure sensor. This could be caused by a sensor that has drifted out of calibration, a wiring fault creating an open or short circuit, or a blocked sensor port. Because the boiler cannot confirm safe operating pressure, it locks out as a precaution. Note that Ravenheat Manufacturing Limited was dissolved in 2025, meaning parts are increasingly scarce — factor this into any repair decision, particularly on older units.
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 E46 fault code mean?
The E46 code on a Ravenheat boiler signals that the PCB is receiving an incorrect, absent, or out-of-range signal from the water pressure sensor. This could be caused by a sensor that has drifted out of calibration, a wiring fault creating an open or short circuit, or a blocked sensor port. Because the boiler cannot confirm safe operating pressure, it locks out as a precaution. Note that Ravenheat Manufacturing Limited was dissolved in 2025, meaning parts are increasingly scarce — factor this into any repair decision, particularly on older units.
Common causes
- Faulty or drifted pressure sensor Common
Over time the internal components of the pressure sensor can drift, causing it to report incorrect readings. For example, the system may be holding a healthy 1.5 bar while the sensor tells the PCB it is only 0.8 bar, triggering a lockout on a false reading.
- Open or short circuit in sensor wiring Common
Moisture ingress at connectors or damage to the wiring between the sensor and the PCB can create intermittent or lost contact. The boiler may work normally for several days and then suddenly display E46 when the connection drops out.
- Blocked sensor port Sometimes
Black magnetite sludge from the system water can pack into the small port where the sensor meets the pipework, physically preventing pressure from reaching the sensing element. Cleaning the port restores function in a significant proportion of cases where the sensor itself is undamaged.
- Air trapped near the sensor Sometimes
A pocket of air close to the sensor can cause pressure readings to fluctuate erratically as bubbles move past the sensing point. Bleeding radiators and allowing the system to circulate can sometimes resolve this without any parts being replaced.
- PCB fault misinterpreted as a sensor fault Rare
If the sensor is producing a correct output voltage but the PCB circuitry that processes that signal is damaged, the boiler still locks out on E46. Roughly one in four cases initially attributed to the sensor turn out to originate in the PCB.
How to fix it
- Check the mechanical pressure gauge (if fitted) DIY safe
Many Ravenheat boilers have an analogue pressure gauge that operates independently of the electronic sensor. Compare its reading with what the display shows. If the mechanical gauge reads 1.0–1.5 bar while the display suggests low pressure, the electronic sensor is the likely culprit rather than genuinely low system pressure.
- Top up system pressure via the filling loop if genuinely low DIY safe
If both gauges agree that pressure is below 1.0 bar, use the filling loop to bring it up to around 1.2–1.5 bar. Turn the filling loop valves slowly and watch the gauge rise. Close both valves once you reach the target. Do not overfill beyond 2 bar. If pressure keeps dropping, there may be a leak and you should call an engineer.
- Reset the boiler DIY safe
Once pressure is at the correct level (or if it was already correct), press and hold the reset button for a few seconds as described in your user manual. Only attempt this two or three times — repeated resets without resolving the underlying fault can cause further damage.
- Thaw a frozen condensate pipe if the fault appeared in cold weather DIY safe
Although E46 is a pressure sensor fault, a frozen condensate pipe can cause multiple simultaneous errors. If it is below freezing outside, check the white plastic condensate pipe that runs to an external drain. Thaw it gently using warm (not boiling) water and reset the boiler.
- Have a Gas Safe engineer inspect and test the sensor wiring Gas Safe engineer
An engineer will use a multimeter to check the wiring loom between the pressure sensor and the PCB for open or short circuits, corroded connectors, and signs of moisture ingress. Damaged wiring can often be repaired rather than replaced, keeping costs down.
- Have the sensor port inspected and cleaned Gas Safe engineer
The engineer will remove the pressure sensor and inspect the small port through which system water transmits pressure to the sensor. If it is packed with magnetite sludge, cleaning it can restore accurate readings without the need to replace the sensor at all.
- Replace the pressure sensor if confirmed faulty Gas Safe engineer
If testing shows the sensor itself is out of specification or non-responsive, it should be replaced. Be aware that Ravenheat ceased trading in 2025 and genuine parts are increasingly hard to source — your engineer may need to locate stock through specialist suppliers or find a compatible equivalent.
- Investigate the PCB if the fault persists after sensor replacement Gas Safe engineer
If a new sensor does not clear E46, the PCB may be failing to process the sensor signal correctly. PCB repair or replacement is complex and expensive work. Given Ravenheat's dissolution, a new PCB may be very difficult to source. At this point it is worth getting a boiler replacement quote to compare costs.
- Call a Gas Safe registered engineer if the fault has not resolved Gas Safe engineer
If the steps above have not cleared E46, or if you are unsure at any point, contact a Gas Safe registered engineer. Do not attempt to open the boiler casing, tamper with wiring, or remove components yourself — this is illegal on gas appliances and potentially dangerous.
Parts you may need
- Water pressure sensor · from £25
- Sensor wiring loom / harness · from £35
- PCB (Ravenheat compatible) · 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–£280, depending on the underlying cause.
Frequently asked questions
Can I fix Ravenheat E46 myself?
The only safe DIY actions are checking the analogue pressure gauge, topping up the system pressure via the filling loop, and resetting the boiler up to two or three times. Any inspection or replacement of the pressure sensor, wiring, or PCB must be carried out by a Gas Safe registered engineer. Working on a gas boiler without Gas Safe registration is illegal and puts you and your household at serious risk.
Are Ravenheat spare parts still available in the UK?
This is an important question. Ravenheat Manufacturing Limited was dissolved in 2025 after its parent company entered voluntary winding-up. Genuine spare parts are becoming increasingly scarce, and many suppliers have already run out of stock. Your engineer may be able to source compatible alternatives, but if a major component such as the PCB or gas valve is also at fault, parts availability could be a real obstacle. If repair costs are approaching £500 or more — or if your boiler is over ten years old — getting a replacement boiler quote makes strong financial sense.
Could low system pressure cause the E46 code even if the sensor is fine?
Yes, in some cases. If genuine system pressure has dropped below roughly 1.0 bar — whether from a small leak, a recently bled radiator, or natural loss over time — the sensor correctly reports low pressure and the boiler locks out. Topping up the pressure to 1.2–1.5 bar via the filling loop and resetting the boiler will clear the fault if the sensor itself is not damaged. However, if pressure keeps falling after you repressurise, there is likely a leak somewhere in the system and an engineer should trace it.
How much does it typically cost to repair a Ravenheat E46 fault?
For most people, the repair involves either a wiring fix or a pressure sensor replacement, which typically comes to between £100 and £280 including parts and labour. A sensor on its own is usually £15–£30, but you also need to factor in the engineer's call-out and time. PCB replacement, if needed, is considerably more expensive — often £300–£450 all-in — and parts availability for Ravenheat models is now limited, which can push costs higher or extend waiting times.