BoilerFaultCodesWhat the manual says
Manufacturer manualHigh temperature protection: Over-temperature thermostat on heat exchanger activated, No water flow through heat exchanger, Over-temperature thermostat fault or bad connection (open circuit), PCB over-temperature condition, Flue fault resulting in recirculation or activation of air pressure switch (if fitted)
From this model's manual
Verified against the Baxi/Baxi 600 Heat installation & service manual.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →
Boiler cover options
Avoid the next call-out bill
A cover plan would handle faults like 2 flashes red: no call-out fees, no surprise bills.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.
All 18 fault codes on the 600 Heat
Seeing a different code? Every code this model can display, in one place.