1 Red Flash Low
Your boiler is experiencing a temporary temperature reading issue and is currently trying to fix itself automatically.
Technical description: Sensor error, sensor fault, temperature fault or flow fault – this is a temporary error, the system should reset on it’s own.
Typical repair cost: £90-180 (including labour)
DIY fix possible
Wait 5-10 minutes to see if the boiler automatically resets itselfCheck that your radiators are bled and there is no trapped air in the systemEnsure your boiler pressure is between 1.0 and 1.5 bar on the pressure gauge
Protect yourself from future repair bills
A boiler cover plan would cover faults like 1 Red Flash — no call-out fees, no surprises.
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Parts commonly replaced
- NTC Thermistor (Temperature Sensor)
- Flow Pipe Sensor
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