| 8 FAULT FINDING. |
8.1  IMPORTANT: If an electrical fault occurs after installation of the appliance, preliminary earth continuity, polarity, and resistance to earth checks should be carried out with a multimeter. On completion of any service/fault-finding task which has required the breaking and remaking of electrical connections, then checks of continuity, polarity, and resistance to earth checks must be repeated. |
| 8.2 No Hot Water / Luke Warm Water |
| 8.2.1 Heat Bank Thermal Store not full with water Check water supply to Feed & Expansion Tank is turned on, check operation of Ball Valve / Solenoid Valve (if fitted) and replace if neccessary. |
| 8.2.2 Electrical Supply to controls not turned on Turn on. |
| 8.2.3 Fuse Blown Check and replace if required. Ensure that a fuse of the correct rating is used (3 Amps to controls). |
| 8.2.4 Cylinder Thermostat not set high enough Check that it is set to at least 75°C |
| 8.2.5 Cylinder Thermostat not in proper contact with cylinder wall Ensure that stat is in contact with the bare copper of the cylinder and strapped securely to the side of the unit. |
| 8.2.6 Heat Exchanger Pump jammed Jump start pump using screw driver on pump spindle. If pump does not turn freely then replace. IMPORTANT: The unit should be protected with scale / corrosion inhibitor to protect the pump. A build up of material within the pump suggests that inhibitor has not been used, and the system will probably need flushing. |
| 8.2.7 Flow Switch not operating Check as follows |
| 8.2.7.1 Using an electrical tester, check that there is a live to the Flow Switch (brown wire). |
| 8.2.7.2 Ensure that all hot water outlets are closed and that the return from the Flow Switch (blue wire) is not live. |
| 8.2.7.3 Check that the return from the Flow Switch goes live when a hot water outlet is turned on. If not then replace Flow Switch. |
| 8.2.8 Thermostatic Blending Valve setting too low Increase to suit |
| 8.2.9 Setting on Heat Exchanger Pump is too low for required hot water flow rate Increase pump setting or reduce draw off flow rate. |
| 8.2.10 Faulty Immersion Heater Check that heater draws correct current (12.5A / 3KW) using a suitable Ammeter. Replace if required. |
| 8.2.11 Immersion Heater Thermostat set too low Set between 80°C and 85°C |
| 8.2.12 Immersion Heater Overheat Thermostat tripping Reduce setting of Control Thermostat to eliminate nuisance tripping. If this does not help then replace Control Thermostat. |
| 8.2.13 Heat Exchanger blocked Power flush |
| 8.3 Hot water supply too hot. |
| 8.3.1 Thermostatic Blending Valve set too high Reduce setting to provide water at desired temperature. |