Unigas RG91 Manual page 35

At least once a year carry out the maintenance operations listed below. In the case of seasonal servicing, it is recommended to carry
out the maintenance at the end of each heating season; in the case of continuous operation the maintenance is carried out every 6
months.
WARNING: ALL OPERATIONS ON THE BURNER MUST BE CARRIED OUT WITH THE MAINS DISCONNECTED
AND THE FUEL MANAUL CUTOFF VALVES CLOSED!
ATTENTION: READ CAREFULLY THE "WARNINGS" CHAPTER AT THE BEGINNIG OF THIS MANUAL.
ROUTINE MAINTENANCE
Check and clean the cartdrige of the fuel filter, replace it if necessary;

carefully check the fuel flexible hoses for leaks;

check and clean the filter on the fuel pump: filter must be thoroughly cleaned at least once in a season to ensure correct working of

the fuel unit. To remove the filter, unscrew the four screws on the cover. When reassemble, make sure that the filter is mounted
with the feet toward the pump body. If the gasket between cover and pump housing should be damaged, it must be replaced;
remove, check and clean the combustion head;

check the ignition electrodes and their ceramic insulators, clean, adjust and replace if necessary;

remove and clean the oil nozzles (IMPORTANT: do not clean the nozzles using metallic or sharp utensils, use only solvents or

steam); at the end of maintenance operations, refit the burner, turn it on and check the combustion. If in doubt, replace the defec-
tive nozzle/s. In case of intensive use of the burner, the nozzles must be replaced at the end of the working season;
examine and clean the detection electrode/photoelement (according to the burner models), replace it if necessary, in case of

doubt, check the detection circuit, after the burner start-up;
clean and grease levers and rotating parts.

Thecnical procedure of self cleaning filters substitution (valid for all models)
1 Close the bowl valve before the self cleaning filter
2 Switch off any electrical equipment on board on the filter (example motorization or heaters)
WARNING! Drain the system by unscrewing the drain screw on the bottom of the self cleaning filter
3 Disconnect the outlet pipe from the cover of the self cleaning filter
4 Remove the cover with all the filter pack, leaving only the bowl on the line
5 Clean any residue on the bottom of the bowl and clean the seat of the O-ring seal
WARNING! Replace the O-ring seal between the bowl and cover
6 Insert the filter pack again making sure to respect the correct inlet/outlet direction or any references on the cover and tray
7 Replace the filter by following the reverse order operations
8 Make sure there is no leakage and give the power to any electrical equipmente on the filter
Flame detection probe
To clean/replace the detection photocell, proceed as follows:
1 Disconnect the system from the electrical power supply.
2 Shut off the fuel supply;
3 remove the photocell from its slot (see next figure);
4 clean the bulbe if dirty, taking care not to touch it with bare hands;
5 if necessary, replace the bulb;
replace the photocell into its slot.
PART IV: MAINTENANCE
35
PART IV: MAINTENANCE