A medical treatment system, such as a peritoneal dialysis system, may include a control and other features to enhance patient comfort and ease of use. For example, a cycler device may include a heater bag receiving section and a lid mounted to cover and uncover the heater bag receiving section, potentially enabling faster heating of a dialysate. A user interface may be moveable to be received into the receiving section and covered by the lid, if desired. The system may detect anomalous conditions, such as tilting of a housing of the system, and automatically recover without terminating a treatment. The system may include noise reduction features, such as porting pneumatic outputs to a common chamber, and others. The system may also automatically detect any one of several different solution lines connected to the system, and control operation accordingly, e.g., to mix solutions provided by two or more lines and form a needed dialysate solution. A cassette control surface may be arranged to have one or more ports that can detect a presence of a liquid, e.g., to identify if a cassette is leaking or has otherwise been compromised.