BoilerFaultCodesYour boiler is working fine, but your external thermostat or timer is not telling it to turn on.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Additional controls not calling for heat
What causes this fault?
This status occurs when the boiler is powered and ready to fire, but it hasn't received a signal from your external controls to start heating. The most common reason is that your wall thermostat is set too low, your timer is in an 'off' period, or the batteries in your wireless controller have run out.
This is frequently reported during the first cold spell of autumn when homeowners forget to switch their programmers from 'Summer' to 'Winter' mode or find their thermostat batteries have died over the warmer months.
DIY fix possible
Check that your wall thermostat is turned up higher than the current room temperature.Ensure your programmer or heating timer is set to 'ON' or 'Auto'.Replace the batteries in your wireless room thermostat if the screen is blank or fading.
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 C(2) — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Potterton Flamingo RS40 RS50 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.
Affiliate links — we may earn a commission at no extra cost to you.