Burner
First, pull out the wires of ignition needle and sensor needle. Second, unscrew and take off the flame shield. Third, unscrew the part connecting the burner and gas water valve, burner and inner shell and clean out the dust. Before putting back the panel, ensure that all parts are connected, especially the O-ring seal. For your safety, please use soapy water test on connection between burner and gas water valve, then operate the machine on lowest flame and highest flame. This will help you check for gas leak.
Thermostat
Pull out the wires on the thermostat, and unscrew the thermostat. The new thermostat should be good contact with the inner shell and remember to insert the wires back on it.
Gas Water Valve
Unscrew the gas water valve with a wrench and a phillips screwdriver;
Then unscrew the ground wire and disconnect all the terminals between ignition box and other parts. Before putting back the panel, please ensure that all parts are connected, especially the ground wire. For your safety, please use soapy water test on connection between burner and gas water valve, then operate the machine on lowest flame and highest flame. This will help you check the gas leak.
Clean the heating plate on the heat exchanger. When the exchanger is no longer working, it needs replacement. Before you cover the panel, use soapy water test for gas leakage.
Ignition Box
First, pull out the wires of ignition needle and sensor needle. Then unscrew the ground wire and disconnect all the terminals between ignition box and other parts. Last, unscrew the ignition box. After replacement, remember the ground wire must to be connected back.