Ideal Atlantic Combi - How to put into Service Mode

To put the Ideal Atlantic Combi into service mode, you need to create a central heating demand. After doing this, you hold the ‘Restart’ and ‘Preheat’ buttons at the same time for ~5 seconds. The boiler display will then show a ‘-‘ then go to ‘SH’ - this is Maximum Rate / High fire. After taking your analyser readings, press ‘Preheat’ - the boiler will then display ‘SL’ - this puts the boiler into Minimum Rate / Low fire. Press ‘Restart’ to exit the service mode.

The readings you’re looking for are:

Maximum CO2%: 9.5 (+/- 0.7)

Minimum CO2%: 8.8 (+/- 0.7)