Mamiya C28 Boiler User Manual


 
CONTROL OF CH TEMPERATURE
The output temperature of CH water is adjustable from a
minimum of about 38°C to a maximum of about 85°Cby
turning the knob C.
Approx CH flow temperatures for the boiler thermostat
settings:
C
Minimum (38 ûC) Ma ximum (85 ûC)
CONTROL OF DHW TEMPERA TURE
ThetemperatureoftheDHWleavingtheboilercanbevaried
from a minimum of about 35°C to a maximum of about 55°C
(within the power limits of the appliance) by turning the
temperature control knob B.
B
Minimum (35 ûC) Ma
x
imum (55 ûC)
Adjustment of the DHW temperature is completely separate
from that of the CH circuit.
The adjustment system integrate d within the boiler
automatically controls the flow of gas to the burner in order to
keep the temperature of DHW delivered constant, between
the limits of maximum and minimum output.
Where the demand is at a low level or with t he temperature
set to the minimum, it is normal to see a cycle of lighting and
extinguishing of the burner when running.
Adjustment
It is advisable to adjust the DHW temperature to a level
commensurate with t he demand, minimising the need to mix
with cold water. In this way, the automatic control facilities will
be fully exploited.
Moreover, where the amount of limescal e pr e sent in the water
may be particularly great, not exceeding the position as
shown in the following illustration (about 50 ûC) minimises
annoying incidences of scale deposits and c logging.
B
In these cases, however, it is advisable to install a small water
treatment device. With such a device you should avoid
periodic descaling.
Consequent ly, the DHW heat exchanger will keep its
performance consistent for a longer period of time with
resulting gas savings.
TO SHUT DOWN THE BOILER
For short periods
To turn the boiler off set the function selector C to the O
position. The appliance operation light A will flash every 4
seconds.
For long periods
When you do not expect to use the boiler for a long period:
1 Switch the electricity supply off.
2 Shut off the gas supply cock and the valves for the water
circuits fitted under the boiler.
3 I f necessary, empty the water circuits.
FROST PROTECTION
This appliance is provided with a built in anti---freeze system
that operates the boiler when the temperature is bel ow 5 ûC
Therefore, when the boiler is not lit and used in cold weather,
with cons equent risk of freezing do not isolate the boiler
from the electricity supply or close the gas inlet cock.
CONDENSATE DRAIN
Thecondensatedrainmustnotbemodifiedorblocked.
Blockage of the condensate drain, caused by debris or
freezing, can cause automatic shutdown of the boiler.
If freezing is suspected and the pipe run is accessible an
attempt may be made to free the obstruction by pouring hot
waterovertheexposedpipeancleaninganyblockagefrom
the end of the pipe. If this fails to remedy the problem the
assistance of a CORGI registered installer or in IE a
competent person should be sought.
ESCAPE OF GAS
Should a gas leak or fault be suspected contact your local
gas supplier without delay.
Do not search for gas leaks with a naked flame.
CLEANING
For normal cleaning simply dust with a dry cloth.
To remove stubborn marks and stains use a damp cloth and
mild detergent.
Do not u se abrasive cleaning materials.
MAINTENANCE
The appliance should be serviced at least once a year by a
CORGI registered installer.
FAUL TS
No heating or hot water
Check that g as and elect ricity are available at the boiler and
that all switches are on.
Check that the system water pressure gauge G reads at least
0,5 bar.
Check the lock---out signal lamp E. If it is illuminated press the
boiler reset button D to restart the ignition sequence.
Hotwaterbutnoheating
Check that the programmer and room thermostat (if fitted) are
both calling for heat.
Heating but no hot water
Check that cold water flows out of the taps at a minimum rate
of 3.5 litres per minute (or 1 pint in 10 seconds or less). If not,
look for stop valves not fully open.
Ifthesesimplechecksfailtosolvetheproblem,orthe
problem recurs, consult your service engineer.