Arrived onsite customers tankless water heater was not running when a sink was open, discovered that the gallons per minute was 2/10 it needs to have 6/10 of a gallon per minute to fire. Cleaned aerators on sink as they were dirty. Cleaned inlet screen on tankless water heater, was getting 5/10 gallon per minute once these were cleaned. Customer decided to pull off the aerator to increase flow. Inspected boiler. Took a look at the customers Buderus boiler. Buderus has recently had the igniter go out it was replaced by the church. Since than it has been working fine. System is fully operational at this time. Flame ionization rod is reading 3.4 micro amps dc, minimum reading should be 1.4 micro amps dc. Hsi was recently replaced and is working correctly. Heat exchanger is clean. Venturi cone is in good shape. All gaskets are in good shape. Inlet gas press Is 12 inch WC. Inducer motor amps are .94 which is within is rating. No leaks are currently present on the system. No issu