17-48 Melfield Gardens

6. OSO FAULT FINDING GUIDE

Problem

Possible cause

Possible solution

Mains supply off

Check and open stopcock

No water from hot taps

Strainer blocked

Turn off water supply, remove and clean strainer

Immersion heaters not switched on

Check and switch on

Cylinder thermal cutout has operated

Check and press reset button

Water from taps is cold

Immersion heater thermal cutout has operated

Check and press reset button

Reduced expansion vessel charge

Follow instructions 5.2 Intermittent or slow discharge from tundish

Intermittent water discharge

Thermal control failure (note: water will be hot

Switch off power to immersion heater(s). When dis charge has stopped check thermal controls, replace if faulty

Expansion relief valve not working properly

Check and replace if faulty

Continous water discharge

Cold water inlet pressure reducing valve not working

Check pressure from valve, if greater than 3 bar - replace

Temperature and pressure relief valve faulty

Drain 10 litres from cylinder and replace valve

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