Sime RX Series - Cleaning and Maintenance; Fault Finding

– Remove front and back panels by loo-
sening the four nuts which fix them
to the panels side.
– Remove the sides.
4.7 CLEANING AND
MAINTENANCE
When the heating is turned off at the
end of the season, it is compulsory to
check the boiler and clean it as follows:
– Take off the boiler top.
–
Remove the smoke chamber cleaning
plate by unscrewing the fastening
screws in the “RX 19-26” boilers.
– Remove the smoke chamber comple-
tely unscrewing the two nuts from
the back side and the nut from the
front side of “RX 37÷55” boilers.
– Extract the burner assembly by
unscrewing the four screws which
fix it to the valve flange.
– With the appropriate brush, reach
down to the rows of plugs of the cast
iron exchanger from the top and
scrape off any scale with vertical
movements.
– Remove the burners from the nozzle
holder header and throw a jet of air
inside them so that any dust can be
removed. Make sure that the top
drilled part of the burners has no
scale left.
–
When disassembling and reassem-
bling the burners be careful not to
force any delicate parts, such as the
thermocouple drill or the ignition unit.
– Scrape off any scale from the boiler
bottom and reassemble all the parts
checking the position of the gaskets.
– Check the stack making sure the flue
is clean.
– Check the correct operation of the
equipment.
After assembling all the gas connec-
tions, a test for gas tightness must be
carried out using soapy water or spe-
cial products. Do not use naked flames.
Maintenance and check of equipment
and safety devices should be carried
out at the end of each season only by
authorized technical personel.
4.8 FAULT FINDING
The pilot burner does not ignite.
- Make sure the gas inflow is regular
and that any air in the pipes has
been eliminated.
- Make sure the hole of the pilot nozz-
le is not blocked.
- Check ignition operations.
The igniter does no spark.
–
Replace the faulty piezoelectric igniter.
– The electrode is misplaced or must
be replaced if broken.
– Make sure there is no false contact
between terminal and igniter cable.
The pilot burner goes out when the
ignition button is released.
–
Make sure the pilot burner flame
covers the thermo-couple sufficiently.
– Regulate gas capacity to the pilot.
– Make sure the split thermocouple
terminals are well fixed to the
overheat stat.
– The overheat stat is faulty and must
be replaced.
– Replace the split thermocouple.
– Replace the gas valve.
The pilot burner does not burn properly.
– Check that the gas pressure is
regular.
– Clean the main air inlet hole of pilot
burner.
– Clean the pilot filter in the gas valve.
Light explosions when the burner
starts and delayed ignition.
– Make sure the pilot burner flame is
not too short.
– Make sure the boiler exchanger is
not too dirty.
The main burner does not ignite.
– This means that the flue smoke stat
has tripped off (point 3.2)
– Make sure power arrives to the gas
valve.
– Replace the electric operator of the
valve.
– Replace the valve.
The boiler reaches the set temperatu-
re, but the radiators do not heat up.
– Make sure there are no air bubbles
in the system, if so purge from
appropriate air vents.
– The room stat is too low or must be
replaced if faulty.
– The connections of the room stat
are not correct. Make sure the
cables are placed on terminals 1
and 4 of the boiler terminal board.
– The circulation pump is blocked,
unblock it.
–
The electric winding of the circulation
pump is faulty, replace the pump.
The boiler pressure relief valve opens
often.
– Make sure the system cold water
pressure is not too high, follow the
suggested values.
– If the pressure relief valve is faulty,
replace it.
– Check pre-load pressure of the
expansion tank.
– Replace the expansion tank if faulty.
The boiler gets dirty easily causing
scaling of cast iron exchanger and
cutting off of smoke stat.
–
Make sure the main burner flame is
well regulated and the gas con-
sumption is proportional to the boi-
ler output.
– The boiler is installed in a poorly ven-
tilated room.
– Insufficient flue draught or not com-
plying with existing standards
– The boiler operates at too low tem-
peratures, set the boiler stat at
higher temperatures.
The thermostat re-ignites with too
high temperature drop.
– Replace the boiler stat which is
faulty.
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