Watts LFL1170 - Manual (Page 3)

Troubleshooting Guide
Series LF1170-M2 and LFL1170-M2
Period Inspection/Maintenance
This valve requires periodic inspection and verification of the out-
let temperature by a licensed contractor. Corrosive water condi-
tions, hot inlet water temperature over 200°F (93°C), unauthor-
ized adjustments or repairs could render the valve ineffective for
its intended service. Regular cleaning and checking of thermo-
stat assembly helps to maximize valve life and mixing function.
Frequency of cleaning depends on local water conditions.
Pressure — Temperature
Minimum Supply Pressure (Static): 30psi (207 kPa)
Inlet Temperatures: hot inlet, 120°F – 200°F (49°C – 93°C),
cold inlet, 40°F – 85°F (4°C – 29°C)
Hot Water Inlet to Outlet Differential Temperature: 5°F (3°C)
LF1170-M2 Temperature Out:
Field range: 90°F – 160°F (32°C – 71°C), adjustable.
Accurate within ±3°F (1.7°C)
LFL1170-M2 Temperature Out:
Field range: 60°F – 120°F (16°C – 49°C), adjustable.
Accurate within ±3°F (1.7°C)
Maximum Temperature: 200°F (93°C)
Maximum Pressure: 150psi (10.3 bar)
Maximum Pressure Differential Between Hot and Cold
Water Supplies: 25%.
Approval: CSA B125 certified
Listing: ASSE 1017 and IAPMO UPC
Symptom Cause Solution
Unable to reach required set point or set
point difficult to set 1. Supply temperatures not within specified
limits
2. Hot and cold supplies reversed
3. Filters are blocked by debris
1. Check differential temperature between hot
and cold supplies and outlet 10°F (5.6°C)
minimum required
2. Reinstall valve with supplies connected to
marked inlets
3. Clean filters
Unable to achieve required flow 1. Too much pressure drop at fixture
2. Checks valve/filters blocked by debris 1. Measure supply pressures and check
against flow chart. Look for restrictions in
valve or piping
2. Clean check valves/filters
Valve does not maintain required temper-
ature or temperature changes over time 1. Fluctuation in supply pressures
2. Check valve/filters blocked by debris
3. Recirculation loop not piped properly 1. Stabilize water pressures with pressure
regulating or balancing valves
2. Clean check valves/filters
3. Pipe recirculated tempered water return so
it connects to hot water source and cold
side of mixing valve (see Product Guide for
piping details)
Discharge temperature too hot or cold 1. Valve not calibrated properly 1. Readjust valve temperature per installation
instructions
Hot water from cold water tap or cold
from hot 1. Check valves fouled 1. Clean check valves/filters
Valve is noisy 1. Water velocity is too high
2. Valve not sized properly 1. Reduce water velocity with pressure
regulating valves
2. Check flow required versus rated flow
capacity of valve
No flow from valve 1. Hot or cold water supply failure or shutoffs
closed
2. Check valve/filters blocked by debris
1. Open shutoffs or restore hot and cold sup-
ply
2. Clean check valves and filters
Flow from valve fluctuates 1. Fluctuation in supply pressures
2. Check valve/filters blocked by debris 1. Stabilize water pressure with pressure regu-
lating valves
2. Clean check valves and filters