Worcester boiler eco mode turning itself off

[Lalitya]

I have recently been setting my boiler on eco mode and it stays on that mode until first thing in the morning, when, at some point, the eco mode stops and pre-heating starts. I haven't been able to catch it the moment the eco switches off. When I spot it I switch it on again. What is happening? I thought it might be to do with the temperature being lower in the morning, but it's very warm today and it still happened.

 

[muggles]

Worcester have made lots of different boilers. Which one is yours?

 

[Lalitya]

Greenstar CDi Classic. The heating timer on the boiler is no longer in use. We use a separate room thermostat connected by blue tooth.

 

[Gasguru]

Have you still got a 2 channel timer fitted on the boiler....the hot water side does the preheat.

 

[Lalitya]

Yes, I do - I hadn't realised that the hot water side was still active, and it was set on "once", which explains why the eco mode was turning off in the morning. I adjusted the setting to "off", and the eco mode has remained on. Thank you for your help.