Armstrong Rada 425 Installation And Maintenance Manual - Page 10
Browse online or download pdf Installation And Maintenance Manual for Control Unit Armstrong Rada 425. Armstrong Rada 425 12 pages. Water temperature controls, groups of fixtures, thermostatic
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Fault Diagnosis
Symptom
1. Only hot or cold water
from outlet.
2. No flow from Mixing
Valve outlet.
3. Mixed water temperature
at TMV outlet fluctuates
and does not respond to
adjustment.
4. Hot water in cold supply
and vice-versa.
5. Mixed water temperature
too high.
6. Mixed water temperature
too low.
7. Mixed water flow rate is
reduced.
8. Water leaking from valve
body.
Cause
a. Inlet supplies reversed (i.e.: hot to cold or vice-
versa)
b. No hot water available from hot water source.
c. Screen/filters occluded or inlet supply fittings
plugged.
d. Refer to Symptom 4 below.
e. Proportioning mechanism (shuttle) trapped against
hot/cold seat.
a. Hot or Cold inlet supply failure; Thermostat holding
correct shutdown function.
b. Screens/filters blocked or inlet supply fittings
plugged.
a. Thermostat not operating correctly.
b. Mixing Valve operating below minimum required
flow rate.
c. Static inlet supply pressures beyond valves
capability to correct.
d. Inlet supply pressures fluctuating beyond valves
capability to correct.
e. Hot water supply temperature fluctuating beyond
valves capability to correct.
f. Partially occluded screens/filters or partially blocked
inlet fittings.
a. Indicates non-functioning check valve (s).
a. Mixing Valve has not been commissioned correctly
and set too high.
b. Mixing Valve has not been commissioned correctly
and was set when the hot supply temperature was
too low.
c. Hot water is migrating into cold supply.
d. Thermostat not operating correctly.
a. Mixing Valve has not been commissioned correctly
and is set too low.
b. Hot water heat is not keeping up with demand.
a. Partially occluded inlet screens/filters or partially
blocked inlet fittings.
b. Inlet supply pressure has fallen.
c. Accumulated pressure losses within the system are
too high.
a. Seals worn or damaged.
Check-Rectify. Tip: check rear of valve under
polymer mounting plate for raised "H" (hot)on
appropriate inlet. If sight evaluation is not possible
consult factory Technical Support for additional
diagnositc tips.
Check-rectify
Check-Rectify
Refer to Symptom 4 below.
Refer to Servicing/Maintenance on Pages 7-8. and
Fig. 8-1. Inspect-Rectify-Replace.
Check-Rectify.
Check-Rectify.
Replace cartridge D33384.
Check that at least 1 GPM is flowing through valve.
Check-Rectify
Check-Rectify
Check by carefully sensing inlet hot supply pipe
work- rectify.
Check-Rectify.
Diagnose by turning off mixed water outlet flow and
check to see if inlet hot pipe work becomes cold
and vice-versa.
Refer to Commissioning on Page 6 - Rectify.
Refer to Commissioning on Page 6 - Rectify.
See Item 4 above.
Replace cartridge D33384.
Refer to Commissioning on Page 6 - Rectify.
Check-Rectify.
Check-Rectify.
Check-Rectify.
Refer to a trained and appropriate authority for
system sizing assistance.
Obtain Seal Pack D33387.
10
Action