Operating instructions
SAVE A SERVICE CALL 
33 
NO WATER FROM THE HOT TAP 
No flow of water from the hot tap may indicate a restriction in or failure of the cold water supply to the water 
heater. Check for water flow at other taps and that the cold water isolation valve (refer to page 46) is fully 
open. 
GAS BOOSTER OPERATING TOO FREQUENTLY 
If the water heater is installed as an in-series gas booster to a solar water heater, you may find that the water 
heater operates more frequently than expected. This will occur when the solar heated water temperature is 
lower than 58°C, which may be experienced during periods of low solar energy gain or if there has been 
heavy hot water usage. Factors to consider are: 
•  Hot tap not used recently 
If a hot tap has not been used for a while, the water in the pipe work between the solar storage tank and 
the in-series gas booster may have cooled down. The in-series gas booster will sense the cooler water 
and this will cause the burners on the water heater to ignite and boost the water temperature when a hot 
tap is first turned on. The burners will extinguish when solar heated water of 58°C or higher from the 
solar storage tank reaches the in-series gas booster (refer also to “Fan Continues to Run after Water 
Heater Operation Stops” on page 33). 
•  Insufficient sunlight 
Insufficient sunlight due to cloudy weather during hotter months or low solar energy contribution in 
colder months may mean the in-series gas booster operates more often. 
•  Collectors shaded 
If trees or other objects shade the solar collectors or if the glass is dirty, the effectiveness of the solar 
collectors will be greatly reduced. Have the trees trimmed or the solar collectors relocated if the 
obstruction is permanent or clean the collector glass. 
Ensure the glass on your solar collectors is free of dust, salt spray or any other matter, which may 
reduce the effectiveness of the solar collectors. If the collector glass becomes dirty, hose down or if the 
solar collectors are accessible, wash the collector glass with water and a soft brush when the solar 
collectors are cool. 
•  Collector area is too small 
For most installations, the number of solar collectors recommended in Rheem literature has been 
proven to provide the required solar energy to meet the average family needs. However, in some 
circumstances, it may be necessary to install an additional solar collector. 
•  Are you using more hot water than you think? 
Is one outlet (especially the shower) using more hot water than you think? 
Very often it is not realised the amount of hot water used, particularly when showering. Carefully review 
the family’s hot water usage. As you have installed an energy saving appliance, energy saving should 
also be practised in the home. Adjust your water usage pattern to take advantage of maximum solar 
gains. 
Have your plumber install a flow control valve to each shower outlet, basin and sink to reduce water 
usage. 
•  Water heater size 
Do you have the correct size water heater for your requirements? 
The sizing guide in the sales literature and on the Rheem website (AU – www.rheem.com.au or NZ – 
www.rheem.co.nz) suggests average sizes that may be needed. 
FAN CONTINUES TO RUN AFTER WATER HEATER OPERATION STOPS 
It is the normal operation of the water heater for the fan to continue running after heating of the water is 
finished. The fan may run for up to six minutes after the burners extinguish, to prepare for the next ignition. 










