Installation manual

10. Fault finding.
Notice: Disconnect electrical supply before removing any electrical equipment cover.
Fault Possible cause Remedy
No hot water
1. Mains supply off
2. Strainer in Pressure reducing valve
blocked
3. Pressure reducing valve
incorrectly fitted
1. Open stopcock
2. Turn water supply off, remove
strainer and clean.
3. Re-fit correctly
Water from hot taps is cold
1. Programmer if fitted is not switched
on.
2. High limit thermostat has tripped
1. Set programmer to call
3. Check and re-set
Intermittent water discharge
through tundish on warm-up
1. Expansion vessel has lost its
charge pressure
1. Turn off stopcock open a hot water
tap check vessel charge pressure and
recharge to 3 bar
Continuous water discharge
1. Pressure reducing valve (PRV) not
working
2. Expansion relief valve not seating
correctly
3. Temperature and pressure relief
valve not seating correctly
1. Check pressure from Pressure
reducing valve if greater than 3 bar
replace cartridge
2. Manually lift the valve once or twice
to clear any debris from the seat
otherwise replace valve
3. Manually lift the valve once or twice
to clear any debris from the seat
otherwise replace valve
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