High
E118 on Main Eco Compact Combi

Your boiler has stopped working because the water pressure in the system has dropped too low and needs topping up.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Primary system water pressure too low

From this model's manual
Verified against the Main/Main Eco Compact installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the pressure within your central heating system drops below a safe operating level, usually because water has escaped the circuit. The most common reasons for this are a leak in the radiator valves or pipework, or air being released from the system through recent bleeding of the radiators.

This fault is frequently seen in autumn when homeowners turn their heating back on for the first time after summer, revealing pressure drops that occurred during the warmer months.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 71 fault codes on the Eco Compact Combi

Seeing a different code? Every code this model can display, in one place.

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