System for detecting drainage flow obstructions in washing appliances

A method of monitoring drainage of first and second washing appliances connected to a common drainage outlet, said first and second washing appliances each having a pump for draining a washing chamber, the method comprising:

• receiving a first data set of power consumption data relating to the operation of the first washing appliance over a monitored period of operation including pumped draining of the washing chamber of the first washing appliance, the first data set of power consumption data indicating power consumed by the first washing appliance from a supply;
• deriving a first operating characteristic of the operation of the first washing appliance during the monitored period from the first data set;
• receiving a second data set of power consumption data relating to the operation of the second washing appliance over a monitored period of operation including pumped draining of the washing chamber of the second washing appliance, the second data set of power consumption data indicating power consumed by the second washing appliance from the supply;
• deriving a second operating characteristic of the operation of the second washing appliance during the monitored period from the second data set;
• wherein the first and second data sets of power consumption data are obtained using one of:
• respective power metering devices connected to the first and second washing appliances arranged to measure the power consumption of the first and second washing appliances;
• and
• a power metering device for monitoring overall power consumption at a user environment comprising a plurality of power-consuming devices including the first and second washing appliances;
• the method further comprising determining an indicator of a drainage condition of at least one of the first and second washing appliances and the common drainage outlet, based on the operating characteristics derived for the first and second washing appliances, wherein the drainage condition comprises at least one of:
• an obstructed drainage path associated with the first appliance;
• an obstructed drainage path associated with the second appliance;
• and
• an obstruction in the common drainage outlet.

A non-transitory computer readable medium storing software code adapted, when executed on a data processing system, to perform a method of monitoring drainage of first and second washing appliances, each having a pump for draining a washing chamber, including steps of:

• receiving a time series of power consumption data relating to the operation of the first washing appliance over a monitored period of operation including pumped draining of the washing chamber of the first washing appliance, wherein the power consumption data indicates power consumed by the first washing appliance from a supply and is obtained using one of:
• a power metering device connected to the first washing appliance arranged to measure the power consumption of the first washing appliance;
• and
• a power metering device for monitoring overall power consumption at a user environment comprising a plurality of power-consuming devices including the first washing appliance;
• deriving, from the time series of power consumption data, a first measure of the duration of a portion of the monitored period comprising said pumped draining;
• comparing the first measure of duration to a first reference value;
• monitoring operation of the second washing appliance, wherein the first and second washing appliances share a common drainage outlet, said monitoring comprising deriving a second measure of the duration of a portion of operation comprising pumped draining of the washing chamber of the second washing appliance;
• comparing said second measure of duration to a second reference value;
• and
• based on comparing the first and second measures of duration to said first and second reference values for the first and second washing appliances, determining an indicator of a drainage obstruction of one or more of:
• the first washing appliance, the second washing appliance, and the common drainage outlet.