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SERViCiNG
FA
UL
T F
iND
iNG
Problems And Remedial Action
Scale
In hard water areas it is recommended that an in-line scale inhibitor is fitted. Reducing
the temperature of the stored water will reduce the rate at which scale forms. If the
recovery rate is badly affected, this is an indication that scaling may have occurred. In
this event, follow the procedures as recommended by a reputable Water Treatment
Company.
General
No water at the tap. Check that the mains water supply is turned ON. Check the line
strainer is not blocked. Check that the combination valve has been fitted so that water
is flowing in the correct direction.
If the water at the tap is cold, ensure that the boiler has been switched ON and is working
correctly. Check that there are no air locks in the primary system. ISOLATE THE UNIT
AT THE MAINS ELECTRIC SUPPLY AND THEN CHECK THE FOLLOWING:
i.
The cylinder thermostat
ii. The thermal cut-out, which can be re-set by pushing the red button
iii. The motorised valve
iv. The boiler thermostat
v. The boiler thermostat cut-out (if fitted)
ANY ENERGY CUT-OUT MUST NEVER BE BY-PASSED UNDER ANY CIRCUMSTANCES.
If the units are not getting hot and the heat source is electrical, ensure that the
immersion heaters are isolated from the mains before re-setting the energy cut-out.
If the immersion heater(s) need replacing this should be done with the units supplied
from Viessmann Limited.
Discharge From Relief Valves
If cold water is discharging from the expansion relief valve into the tundish check the
pressure on the expansion vessel when cold and recharge if necessary.
If the fault continues and the problem cannot be stopped by operating the easing
control a few times then either the Pressure Reducing Valve or the Relief Valve may
be at fault. If the cold water pressure is too high, this would suggest that the Pressure
Reducing Valve is at fault and the Viessmann approved replacement should be fitted.
If the pressure is correct then the Relief Valve will require replacing with a Viessmann
approved component.
See Commissioning for drain down procedure.
If there is an overheat fault and very hot water is being discharged, turn off the heat
source, but not the water supply.
When the supply is cool, check thermostats and energy cut-outs in the boiler and
immersion heaters and replace the faulty component with a unit supplied by Viessmann
and check that it works correctly before returning the system to full operation.
Summary of Contents for Vitocell 200 Cylinder
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