bubble test for gas and visual examination for water (see p. 7.3.7
и 7.4.5).
13.4. Water and gas block replacement
13.4.1. Remove the casing, see p.13.1.
13.4.2. Disconnect three wires from the electromagnetic valve 16.
13.4.3. Disconnect two wires from the micro switch 17
13.4.4. Disconnect the gas and water supply to the appliance.
13.4.5. Disconnect the adapter 15 from water and gas block 4.
13.4.6. Screw out four self-threading screws connecting the water and gas block 4 to the carcass carrier 1 and re-
move the water and gas block.
13.4.7. Install the new water and gas block.
13.4.8. After installing and connecting the water and gas block check the gas and water connections for airtightness.
Water and gas leakages are unacceptable.
13.4.9. Check the appliance
’s operation with the new water and gas block.
13.5. Water block replacement
13.5.1. Remove the casing, see p.13.1.
13.5.2. Disconnect water supply to the waer and gas block 4.
13.5.3. Disconnect the pipe nut 7 from water block 6.
13.5.4. Screw out two fixation screws connecting the water block 6 to the casing of the water and gas block.
13.5.5. Screw out two fixation screws connecting the water block 6 to the carcass carrier 1 and remove it.
13.5.6. Install the new water block.
13.5.7. Check the joints for airtightness. Water leakage is unacceptable.
13.5.8. Check the appliance
’s operation with the new water block.
13.6. Replacement of cold water inlet pipe to the heat exchanger
13.6.1. Remove the casing, see p.13.1.
13.6.2. Screw off the captive nut of the pipe 7 from the water block tap 6.
13.6.3. Screw off the captive nut of the tap of the heat exchanger 2 and remove the pipe together with the layings 26
and 27.
13.6.4. Install the new pipe with new layings.
13.6.5. Check the appliance
’s operation. Water leakage is unacceptable.
13.7. Replacement of the hot water output pipe from the heat exchanger
13.7.1. Remove the casing, see p. 13.1
13.7.2. Disconnect the wires and remove the thermorelay 22, screwing off the yoke screws 25.
13.7.3. Screw out the hot water temperature sensor 30 together with the ring 31.
13.7.4. Screw out two screws connecting the tap of the pipe 8 to the carcass carrier 1.
13.7.5. Screw off the nut of the pipe 8 from the tap of the pipe of the heat exchanger 2 and remove the pipe.
13.7.6. Install the new pipe.
13.7.7. Check the appliance
’s operation. Water leakage is unacceptable.
13.8. Replacement of thermorelay (water overheating sensor)
13.8.1. Remove the casing, see p. 13.1
13.8.2. Disconnect two wires from the thermorelay 22 on the hot water outlet pipe 8.
13.8.3. Screw off two self-threading screws of the connection of the thermorelay with the yoke 25 and remove it.
13.8.4. Install the new thermorelay.
13.8.5. Check the appliance
’s operation with the new thermorelay.
13.9. Replacement of thermorelay (draught sensor)
13.9.1. Remove the casing, see p. 13.1.
13.9.2. Disconnect the wires from the thermorelay 22.
13.9.3. Remove the carrier 23 from the thermorelay 22 from the gas cleaning plant, pushing up the coupling pawl on
the carrier.
13.9.4. Screw off two self-threading screws connecting the thermorelay 22 to the carrier 23 and remove the
thermorelay.
13.9.5. Install the new thermorelay.
13.9.6. Check the appliance
’s operation with the new thermorelay.
13.10. Replacement of the ignition plug or the flame sensor
13.10.1. Remove the casing, see p. 13.1.
13.10.2. Disconnect the wires from the ignition plug 18 or from the flame sensor 19.
13.10.3. Screw off two self-threading screws connecting the plank 21 to the carrier 20, remove the ignition plug 18 or
the flame sensor 19
13.10.4. Replace the ignition plug or the flame sensor.
13.10.5. Check the appliance
’s operation with the new ignition plug or flame sensor.
13.11. Replacement of water temperature sensor
13.11.1. Remove the casing, see p. 13.1
13.11.2. Disconnect two wires from the temperature display 12.
13.11.3. Screw out the water temperature sensor 30 from the hot water outlet pipe tap 8.
13.11.4. Install the new sensor.
13.11.5. Check the appliance
’s operation with the new sensor comparing the water temperature readings on the dis-