12
SETTING THE WATER TEMPERATURE
The AquaStar 170 water heater contains a flow
restrictor set at 4 1/4 gpm. Its purpose is to
assure that the hot water temperature will al-
ways be within a comfortable range regardless
of how high one may turn on the hot water fau-
cet or how many faucets may be turned on. Your
AquaStar model 170 also has an automatic ther-
mostatic control with a manual temperature
setting (Fig. 2 letter H p. 6). For energy effi-
cient operation, we recommend operating this
heater at the lowest temperature which you re-
quire in your application. This will provide a
more consistent temperature over a wider range
of flow. Lower temperature settings help pre-
vent temperature fluctuations that may occur
when other water outlets are used simulta-
neously or overall water pressure changes or
excessive cold water has to be added. In hard
water areas, reducing the water temperature
greatly reduces the potential for mineral scale
build-up in the heat exchanger.
What is the best temperature setting?
Because AquaStar water heaters can deliver
endless hot water at the exact temperature which
you have selected, there is no need to set it for
Drainage: Drain the heater if there is any dan-
ger of freezing. Shut off the water supply, open
all hot water faucets, and disconnect the lowest
AquaStar fittings and the connections to the wa-
ter valve (Fig 2, (R), page 6). Loosen the 2 re-
taining screws at the connection to the gas valve
and rotate the water valve to empty all the water.
The pressure-temperature relief valve operation
should be checked. Perform a manual opera-
tion of this valve at least once a year ensuring
that a drain is nearby to receive any discharge
(see section 4, page 9). Take precautions to
avoid contact with hot water coming out of dis-
charge opening as well as to prevent water dam-
age. Do not plug the relief valve. If the relief
MAINTENANCE AND SERVICE
Position "5" on the temperature dial is the pre-
ferred starting point for setting the temperature
control. This setting provides approximately
130ºF (See the flow rate chart, p 18).
Positions "2" and "3" provides approximately
105º-110ºF, adequate for a shower.
Positions "4" through "6" are intermediate set-
tings between warm and very hot.
Position "8" allows for the hottest temperature
of about 150ºF up to about 2.6 gallons per
minute. WARNING:150º can cause third de-
gree burn.
Note: 105ºF is the maximum recommended
for a hot bath. The temperature you select will
hold over a range of water flow rates. (See
chart, Fig. 6, page 18). You may further vary
the temperature by signficantly changing the
flow rate, particularly at the highest tempera-
ture settings.
very hot water and then mix in cold. It just
doesn't make sense to overheat water then mix
in a lot of cold water to cool it off. Remember
you cannot run out of hot water with an
AquaStar, so set the dial for the (exact)
temperature that you need.
Approximately once a year, the AquaStar should
be checked, cleaned and serviced as neces-
sary. The following operations must be per-
formed by a qualified service person:
Vent System: Should be checked annually.
Clean and repair as needed.
Water Valve (Part #34343): The water valve
on this heater should be serviced periodically
depending on hardness of water and conditions
of use. This consists of replacing the Push
Rod Assembly (part #38475), and the Dia-
phragm (part # 33071).
