Ricoh 3110 noisy self maintaining

[esjayjay]

I have a Ricoh 3110 and it is self maintaining throughout the night but its every 20 mins, never used to, used to hear it once maybe twice. Past 2 nights its been every 20-30 mins. The waste cartridge replaced in April, Showing almost empty. Any advice please, Is there an eco setting and setting for how often it self maintains?

Looks like it will be turned off at night and on in day, Never used to and worried I will forget to knock it on in morning. Its all been perfect since January.