Heatrae Sadia ELECTROMAX SOLAR Installation & Servicing Instructions Manual page 66

3. Undo the compression connections connecting the discharge pipwork (D1) to the tem-
perature and pressure relief valve and the central heating pressure relief valve.
4. Disconnect the central heating pressure gauge from the central heating pressure relief
valve.
5. Undo the compression fitting connecting the central heating pressure relief valve to the
central heating primary circuit.
6. Fit the new central heating pressure relief valve. Tighten the compression fitting between
the central heating pressure relief valve and the central heating primary circuit and re con-
nect the discharge pipework.
8.20 CENTRAL HEATING AUTOMATIC BYPASS VALVE
1. Close the central heating isolation valves and drain the central heating primary circuit.
2. Undo the two compression fittings connection the automatic bypass valve to the central
heating primary circuit.
3. Fit the new automatic bypass valve. Tighten the two compression fittings
8.21 ELECTRIC BOILER
1. Close the central heating isolation valves and drain the central heating primary circuit.
2. Unscrew the screw holding the electric boiler PCB housing cover in place and remove the
cover.
3. Disconnect the cables from the Electric Boiler PCB terminal blocks.
4. Undo the compression fitting connecting the electric boiler to the central heating primary
circuit and remove the electric boiler, disconnecting it from the push fit elbow.
5. Fit the new electric boiler. Re fit the electric boiler housing and secure to the Electromax
Solar right hand side panel. Re connect the cables to the PCB terminal blocks. Tighten the
compression fitting. Replace the PCB housing cover and secure in place with the screw.
8.22 ELECTRIC BOILER MAIN PCB
Note: The central heating circuit does not need to be drained to replace the electric boiler
PCB.
1. Unscrew the screw holding the electric boiler PCB housing cover in place and remove the
cover.
2. Disconnect the cables from the Electric Boiler PCB terminal blocks (conn1 & conn5).
3. Disconnect the thermistor wire (conn4), the over temperature cut out wire (conn3) and the
ribbon cable (conn2) from the Electric Boiler PCB.
4. Disconnect the six wires to the electric boiler heating elements (note which wires are con-
nected to which element leg)
5. Unscrew the four screws holding the PCB in place
6. Fit the new PCB and secure in place with the four screws (ensure that sufficient heatsink
compound is applied between the electric boiler pipe and the PCB heatsink). Re connect
all wires. Re fit the electric boiler PCB housing cover and secure with screw.
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