BoilerFaultCodesYour boiler has detected that the water temperature is too low and has activated its internal freezing protection mode to prevent pipes from ice damage.
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: Anti-frost mode on water circulation
DIY fix possible
Ensure your heating is switched on and the thermostat is set to a reasonable temperature to allow the boiler to heat the water circuitCheck that your boiler's external flue is not blocked by ice or debrisMonitor the unit for 30 minutes to see if the code clears once the system warms up
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 6 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Chaffoteaux Calydra 100 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.