A novel carpet extractor is disclosed having a first cleaning liquid conduit that communicates a supply reservoir with a cleaning liquid distributor via a first valve and a second cleaning liquid conduit that communicates the supply reservoir with the liquid distributor via a second valve. The compounds may be useful to prevent yellowing and deterioration of organic materials preferably polymers, such as polyurethane foams as one example. There are two major functions, with sub-functions within each. When a new node in the wireless mesh network is detected as a past join node, the device key assigned to the past join node is assigned to the new node again.