Customer called about inconsistent hot water coming from three year old tankless water heater. Performed troubleshoot to try and determine cause. Checked for potential cross connection and found none Recirculation pump is present but customer has app to set schedule for times that the pump will run. The pump was set to run starting at 6am snd customer explained they usually shower around 6:15 in the morning. Due to the size of the home that is not adequate time to recirculate hot water through the recirc loop in the home and is likely the cause for inconsistent hot water when trying to shower. Set recirc pump to run from 5am until the evening when they go to bed and be off at night to see if this helps resolve the issue. If it does not, then a potential deeper diagnostic of the tankless unit itself may be necessary Adjusted temperature settings in shower cartridges thoughout home as a courtesy Thank you for choosing TE Certified