BoilerFaultCodesYour boiler is working correctly and is simply waiting for a signal from your thermostat or timer to start heating.
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: Boiler in standby, no heat energy demand
What causes this fault?
This code appears when the boiler has reached its required temperature or has fulfilled its current task and is now sitting in a 'ready' state. It is physically waiting for your thermostat to detect a drop in room temperature or for a timed schedule to trigger a new request for heat. Essentially, the system is resting because it believes every part of your home is currently warm enough.
This status is more frequently observed during spring and autumn when the weather is mild and the thermostat reaches its target temperature quickly.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or app is set to an 'On' period.Check if your wireless thermostat has run out of batteries.
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A boiler cover plan would cover faults like 203 — no call-out fees, no surprises.
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