Display normal but no heat to the space

What is going on

The boiler looks fine but the heating loop stays cold.

Likely causes

• No thermostat/end switch call on terminals 9-10
• Outdoor temperature above warm weather shutdown (2.025)
• Supply already above CH setpoint
• CH pump not running or not wired to 7-8
• DHW priority active

Check in this order

1. Make a call the radiator icon flashes during a CH demand. If unsure about the thermostat, jumper terminals 9 and 10.
2. No radiator icon read outdoor temperature at 1.004 and compare with the warm weather shutdown (2.025); above it the boiler will not heat.
3. Icon flashing but no fire compare the main-screen supply temperature against the CH setpoint (0.003 / 2.003). The burner waits until supply drops below the setpoint by the differential. Raise 2.003 if it is too low.
4. Make sure the CH pump runs and is wired to terminals 7 and 8.
5. Radiator icon steady and faucet icon flashing means a DHW call has priority. If this lasts too long, raise the DHW setpoint or shorten the DHW priority time (2.043).

More boiler guides

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• Cleaning the combustion side of the heat exchanger
• Display is blank
• Display normal but no domestic hot water (indirect tank)