INST201702_TMV_ZW1070
ZURN.COM.AU
TROUBLESHOOTING
MATERIALS
Body
Bronze ASTM B 584
UNS C84400, nickel plated
Internal brass
Brass ASTM B-16 UNS C36000
Piston
Polysufone
Guide Tube
Noryl GFN2
Spring & Screen 300 Series Stainless Steel
Seals
Viton
Checks
Noryl GFN2
MAINTENANCE
SERVICING THE STRAINERS
The strainers on the inlet supplies can be serviced by loosening the
union nuts, removing the valve from service and clean the screens
thoroughly with water after disassembly. Where water quality is a
concern it may be necessary to install additional line strainers.
SERVICING THE CHECK VALVES
The check valves can be serviced by removing them from the body.
Flush the check valves thoroughly with water removing debris
from the seat and seat washers. Reinstall the check valve by
pushing them into the body flush to the body, spring first. Make
sure that the poppet and seat washer is facing you.
OPERATION
The valve internals themselves cannot be serviced. If the valve fails
it must be replaced. The function of the valve can be checked by
measuring the temperature of the water at the outlet nearest to
the valve. If the temperature is /- 1.8°C of the initial set
temperature, the valve is functioning correctly. If the temperature
has changed by more than +/- 1.8°C it is likely due to a build up of
debris in the stainers or a change in the supply condition.
ZURN AUSTRALIA
49 LAKESIDE DRIVE BROADMEADOWS VIC 3047
PHONE: 1300 00 ZURN
EMAIL: [email protected]
Removing Cap
Temperature Adjustment
FLOW RATES (GPM
)
PRESSURE LOSS (PSIG)
0
20
40
60
5
0
10
15
20
138
276
414
0.
0
3
.6
0
3
.95
1.3
PRESSURE LOSS (kpa)
FLOW RATES (l/s
)
MODEL ZW1070 (STANDARD & METRIC)
FLOW CHARACTERISTICS
PROBLEM
CAUSE
SOLUTION
The desired mixed water temp. cannot be
obtained or valve is difficult to set
Hot and cold supplies are reversed, valve
is full of debris or strainers are fouled
Re-fit valve so H & C are correct, flush valve
with water and clean strainers
Mix. Temperature is unstable
Strainers are fouled or fluctuating supply
pressure
Clean strainers and Install PRV's on
H & C inlet supplies
Mix T
emperature changing over time
Fluctuating supply pressures or strainers
are full
Install PRV's and clean strainers
Valve is set incorrectly
Adjust mix. Temperature to 35°C - 46°C
No flow from the valve outlet
Hot or Cold water supply failure or strainers
are fouled
Restore inlet supply & check mix.
Temperature and clean strainers
Flow rate reduced or fluctuating
V
alve or inlet fitting fouled by debris
Check valve and inlet fittings for blockage
Mixed water temp. too Hot or Cold
Valve has been tampered with, valve
incorrectly set, or inlet temperatures are
not within specified limits
Re-adjust to required set temp. to ensure
inlet temperatures are within specified
limits
Mixed water temp. does not change when
the temp. adjuster is moved
Hot and Cold supplies are reversed
Refit the valve to correct Hot and Cold
Hot water flows into the cold water system
or vise versa
Check valve is fouled
Clean strainers and remove debris
Valve is noisy
Water velocity is too high
Reduce water velocity
Either full Hot or Cold water flowing
