BoilerFaultCodes 5 High
Your boiler has detected that the water pressure inside the system has dropped too low to operate safely, or a valve is stuck open causing water to bypass the heating system.
Call an engineer soon
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Low inlet pressure / Pressure relief valve in change over valve stuck open or defective
Typical repair cost £120-250 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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 5 — no call-out fees, no surprises.
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Chaffoteaux Celtic 2 24 Rsc 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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