Specifications

6 720 644 063
Troubleshooting
41
7.3 Amount of Hot Water
The water is not hot enough. Is the gas supply valve fully open?
(Using the remote controller)
Is the water temperature setting appropriate?
If the amount of hot water required is very high, it is possible for the tem-
perature to be lower than the temperature set on the remote controller.
Decrease the amount of hot water passing through the unit and the tem-
perature should stabilize.
The water is cold when only a single
fixture is open.
The unit will not heat the water if the flow rate is less than 0.5 GPM (2L/
min.). Open the fixture more or open other fixtures so that a greater flow
passes through the unit, and the unit should begin heating again.
Fluctuations in hot water tempera-
tures.
Clean the water filter of any debris.
(Using the remote controller)
Set water temperature at 115°F (48°C) to 120°F (50°C). This will allow
you to use a higher flow of hot water thus meeting the minimum flow
requirement of 0.5 GPM (2L/min.)
(Using the remote controller)
Setting temperature cannot rise.
Is the maximum temperature setting appropriate?
Table 10
The amount of hot water at a certain
fixture is not constant.
When hot water is demanded at other fixtures, the amount available may
be reduced. The maximum flow available from the 660 EF, 660 EFO is
5.3 GPM (20.0L/min.) at a 45°F ( 25°C) temperature rise.
Pressure fluctuations and other plumbing conditions can cause the tem-
perature and pressure at a fixture to be unstable, but it should stabilize
after a short time.
There are some types of hot water taps that discharges large volumes of
hot water at first but stabilize after time.
To keep the temperature stable, the heater limits the amount of water
that can flow through it to a small amount initially, but the amount
increases over time.
The amount of hot water in the tubis
less/more than the set amount.
When hot water is used for other fixtures while filling the bath tub, the
tub will not fill as much.
If there is water in the tub already, or when filling is stopped and
restarted, the tub will fill more.
The flow meter alarm does not sound
even when filled to the set amount.
The flow meter alarm is set to sound when hot water is continuously dis-
charged for the set volume of water. If mixing valves are used, or if cold
water is mixed with hot water at the fixture, the tub will fill more than the
setting of the flow meter alarm.
Amount of hot water available has
decreased over time.
Is the water filter clogged?
Table 11