Rinnai PRESTIGE Operation & Installation Manual page 11

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Problem
Insufficient or no hot Water
continued
No Water from the hot tap
Gas Booster operating too
frequently
High electricity or gas bill
Water flow fluctuations
Water Hammer
Rinnai Australia
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Cause
Booster element Thermostat Settings
Restriction in the hot tap or failure of the cold water
supply to the water heater.
Insufficient Sunlight - Collectors shaded
Excessive hot water consumption
Solar Control unit switched off
Temperature and pressure relief valve / Expansion
Control valve discharging water continuously
Lack of solar gain
High Electricity Tariffs (electric boosted systems only) Electric Boosted Systems
Little or no water circulation in the solar 'flow and
return' loop
One or more hot taps opened at the same time
Hot and cold water plumbing in the premises
Electric Boosted Systems:
The end user can check the temperature of hot water delivered with a
thermometer placed under the closest non tempered outlet (usually the kitchen
sink).
CAUTION: Take care to avoid scalding. This test should be done early in
the morning after overnight electrical boosting before any hot water is
used. The temperature of the water delivered should be at least 55° C
(allowing for heat losses in pipe work). 
If this is not the case or the temperature needs to be increased contact Rinnai.
The thermostat settings of the heating element thermostat can also be confirmed
directly by a qualified person as described under 'hot water storage & delivery
temperature'. The settings can be increased if required. Contact Rinnai.
Gas Boosted Systems:
The delivery temperature of gas boosted systems is normally 60 or 65°C. Iff
temperatures are higher than this, the flow of water through the gas booster will
reduce and may result in insufficient flow rate.
The end user can check the temperature of hot water delivered with a
thermometer placed under the closest outlet (usually the kitchen sink).
CAUTION: Take care to avoid scalding. If the temperature is higher than
65°C the gas booster may be preset incorrectly. Contact Rinnai.
Check for water flow at the other taps and that the cold water isolation is fully
open.
Ensure the trees or other objects are not shading onto the collector surface (Trim
the trees or relocate the solar collector if the obstruction is permanent).
Make sure the glass on the collector is not dirty.
See entry under 'Insufficient hot water'.
If the solar control unit is switched off there will be no solar pre-heating of water
resulting in the water being heated entirely by electricity or gas' boosting'. Check
the power outlet for the solar control unit is switched on.
See entry under 'Insufficient hot water'.
Reduced sunlight:
Reduced sunlight due to overcast weather in summer or low solar contribution in
winter will result in an increased dependence on electricity or gas boosting.
Higher electricity or gas bills under these conditions, especially in winter, are
normal.
Collectors shaded:
If the solar collectors are shaded by trees or other objects, or the glass is dirty,
the effectiveness of the collectors is greatly reduced. Arrange for trimming of the
trees or relocation of the solar collectors if the obstruction is permanent. Arrange
for cleaning of the collector glass.
Solar collectors incorrectly positioned
Check that positioning and alignment of solar collectors is in accordance with the
section 'Location and alignment of solar collectors'.
WARNING: Persons working from elevated surfaces such as roofs must be
adequately trained an qualified in accordance with local OH&S requirements.
The electricity tariff will determine the running costs of the system. It is important
the end user is aware of the applicable tariffs. Contact your electricity supplier to
confirm what these tariffs are.
There are numerous causes of little or no circulation in the solar 'flow and return
circuit the circulation of water through the collectors. These causes must be
investigated by a qualified person. Contact Rinnai.
More than one or two hot taps in use at the same time may cause a decrease in
the hot water flow from the taps.
Is there more than one or two hot taps open, or are appliances such as a
dishwasher or washing machine, in use at the same time?
Ensure only one or two hot taps are on at one time.
Check the flow of the water from one tap, eg. the shower. The shower should be
adjusted so the hot tap is fully open.
Have a plumber check clipping of hot and cold water pipework and install a
pressure limiting valve and water hammer arrestor as required.
9 Solar Split Systems Operating / Installation Manual Version 8 - 18/10/10
Remedy