Hoval TopVent GV, Operating Instructions Manual

Page: 34 / 44

11.4 Measures
After identifying the problem, use the Case number to find the possible cause in
this paragraph.
Case 1: Flame lasts only 5 seconds after ignition
■ No flame is detected:
– Check the ignition/ionisation cable and the electrode. The cable should have
a resistance of 1 kΩ.
■ The unit is not earthed properly.
■ The circuit board is defective.
Case 2: No flame after ignition
■ There is not enough gas pressure.
■ The gas mixture is too poor.
– Re-adjust the gas valve (see section 9.5).
■ The gas valve does not open.
– During ignition, check for a 230 V voltage on the valve.
■ Check if the ignition electrode sparks. If not:
– Check the cable and electrode.
– Check if the burner control gives a spark output.
– Replace defective components.
Case 3: Heat exchange sensor or flue gas sensor overheated
■ Check if the connectors J12 and J6 are plugged in correctly and if the terminals
J12-1 / J12-4 (optional overheating protection) are jumpered.
■ Check if the system fan supplies enough air.
■ Check the settings of the gas valve.
Case 4: Heat exchange sensor or flue gas sensor not detected, or short circuit
■ The heat exchange sensor consists of 2 internal sensors. The readings of these
sensors may differ too much.
– Measure the resistance of each sensor. The resistance should be 20 kΩ at
25 °C and 25 kΩ at 20 °C.
– If the measured values differ too much, replace the sensor.
Case 5: Too many flame failures while burning
■ The gas supply is not constant. This results in a drop in gas supply pressure
while burning.
– Check the gas supply pressure while the heater is burning.
■ The burner pressure for partial load operation is too low.
– Check the burner pressure in partial load operation and adjust if necessary.
■ Flue gas is sucked back into the air inlet, resulting into a lack of oxygen.
– Check the flue gas system and combustion air supply. Only certified, original
parts should be used.
Case 6: Gas blower does not work
■ Check if the gas blower fan is blocked.
■ Check if the wiring is damaged.
■ The gas blower is defective.
Case 7: Gas blower rotates at the wrong speed
■ Check if the gas blower runs smoothly.
■ Check if the wiring is damaged.
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TopVent ® TG | GV | MG
Operating instructions
Troubleshooting
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