I'm happy to declare our imminent abandonment of Servo's for more of the the faultless Evita's
4x Servo 300's: Constant O2 cell failures (any supplier), control pots, and expensive service kits.
One Servo-i: Several expensive touch screen assemblies due to internal failures, and several patient cassettes, with internal failures and the most recent is the failure of the nebuliser driver which only happens to be located on the expensive main control board. Aside from the parts, every fault involves getting an engineer in to reload the software.

The nurses like to use it but its not as reliable as the Evitas we've been using elsewhere totally fault free for years...
Drager is definately the way to go...
