BoilerFaultCodesYour boiler's internal sensor is struggling to detect the correct water pressure levels, which is preventing the system from running safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault: Water press. sensor (signal too weak) - Water pressure sensor reports that the water pressure is too low
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the water pressure sensor, or the sensor itself has failed mechanically. The most common reason is that the sensor has become blocked with system debris or has suffered an electrical failure, meaning it can no longer confirm there is enough water to safely heat the home.
DIY fix possible
Check the digital or manual pressure gauge to see if it is below 1.0 barUse the filling loop valves under the boiler to top up the pressure to 1.5 barReset the boiler to see if the error clearsIf the pressure is already at 1.5 bar and the code persists, the sensor likely needs professional replacement
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F.73 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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