Powermax Boiler 155X

The green light will only come on when the burner is operating, which it will do if the hot water temperature in the boiler's internal tank falls below a set value (normally 80 degrees C). If you have hot water set to continuous, you will probably be able to run quite a bit of hot water before the burners need to come on to bring the internal tank temperature up again - it doesn't come on every time you run hot water, as it does with a combi boiler.

The red lights indicate when the programmer is 'on' in accordance with the on/off times which have been set by the user (separately for hot water and central heating) - but if the hot water is set for continuous (top position on the three-way switch), the programmer is by-passed (and you won't get any central heating!).

Does that help at all? Have you looked at the User Manual? - you can download a copy from Mike's site (http://www.powermax-repairs.co.uk/Powermax%20user%20instructions.pdf)