14.0 Testing low water pressure safety switch
The low pressure shut down switch has been pre-set at
the factory to shut down the production of the WM
unit if the incoming feed water pressure drops below
18 psi. To provide protection that the RO pump is not
operated in a dry mode.
14.1 To test the LPP the WM must be in operation and
producing RO water. With the unit operating turn off
the incoming feed water supply into the WM. The
WM inlet solenoid valve should close and motor will
shut down and stop producing RO.
14.2 Turn on the incoming feed water supply into the
WM unit and the unit will start up and start producing
RO water automatically.
SPECIAL NOTE: Low water pressure caused by
inadequate water flow from source or by clogged
pre-filter will cause the RO unit to osculate
between off and on. The low-pressure switch
sensing low pressure then the unit is operating
causes the unit to shut down. Then as soon as the
unit shut down the low-pressure switch senses the
correct water pressure and re-starts up. If the unit
is osculating because of this condition, this will
cause major damage to the unit. Turn off unit
immediately. If the condition is cause due to the
lack of water flow increase water line size or add
low water pressure pre-booster pump. Contact
Watts Pure Water STS department.
If osculation is caused by clogged pre-filter, change
pre-filter. See maintenance schedule filter
changing
System Disinfecting for consumable water
If System is used to supply RO drinking water for
human consumption disinfection is recommended.
System should be disinfected at least once every 12
months.
(a) Allow system to fill storage tank before
disinfecting post treatment down stream of WM.
(b) Close a ball valve down stream of delivery pump
and open a faucet or line to relief water pressure
from the RO water lines.
(c) Remove all filter cartridges from any post
treatment housing down stream of delivery
pump.
(d) Add 1 teaspoon of hydrogen peroxide to all filter
housings down stream of delivery pump and
reconnect to filter housings without the cartridge.
(e) Add 12 oz. of hydrogen peroxide for every 50
gallons of water in storage tank and wait for 30
minutes.
(f) Open ball valve down stream of delivery pump
and flush 5 to 10 gallons RO water from every
dispensing port.
(g) Replace any post filter cartridge back into their
housings.
(h) Any hydrogen peroxide still in storage tank or in
the water lines will be removed by the final
polishing. Or break down to oxygen and water
over 24-hour period.
MAINTENANCE Schedule
At least once a month review operation of unit and
fill in the information required in operational
chart.
WM-unit pre-filters should be changed once every
3 to 6 months or even sooner depending on
incoming feed water conditions.
Changing Pre-filters
1. Turn off the unit by placing the toggle switch into
the off position.
2. Turn off incoming feed water supply to WM unit.
3. Open flush ball valve to de-pressurize the pre-
filter housing and drain the water into a pail or
drain.
4. Remove the filter housing by turning to the left.
Note: A filter-housing wrench may be need.
5. Drain and remove filter cartridge from housing.
Discard used filter cartridge. DO NOT discard
filter-housing o-ring.
6. Clean filter housing with warm soapy water.
Rinse with clean water.
7. Clean and lubricate filter-housing o-ring with K-
Y Jelly or silicone grease. Do not use petroleum-
based lubricant.
8. Inserts filter cartridges into the appropriate filter
housing and reinstall filter housing back into
place turning to the right (hand tight only).
9. Follow normal start up procedures.
WM-membrane may need to be replaced once
every 12 to 24 months or sooner depending on the
incoming feed water chemistry and how the unit is
operated:
Watts Pure Water
Sales and Technical Support Department Toll free
within the United States (1-888-774-7405). Outside
the United States (623 505-1512).
Monday Thurs Friday: 8:00 AM – 5:00 PM
Mountain Standard Time
