BoilerFaultCodesYour boiler has detected that the water pressure is too low, which has caused it to stop working to avoid damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Water pressure error – increase water pressure
What causes this fault?
This fault occurs when the system lacks enough water to circulate safely, triggering a safety shutdown. The most common reasons are a slow leak in the pipework or radiators, or having recently bled your radiators without topping the pressure back up.
This is common in autumn when homeowners turn their heating back on for the first time and discover the pressure has naturally dropped over the summer.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Open the taps on the filling loop slowly until you hear water entering the system.Watch the pressure gauge and close the taps once the needle reaches 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E37 — no call-out fees, no surprises.
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Keston C36 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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