Troubleshooting; Specification - Kohler Rada 32E Product Manual

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Make
sure that the item is installed by a competent installer.
Shut off the main water supply.
Observe all local plumbing and building codes.
Provided that the thermostatic mixing valve is installed,
commissioned, operated within the specification limits and
maintained according to this Manual, the risk of
malfunction, if not eliminated, is considerably reduced.
The use of the word 'failsafe' to describe the function of a
thermostatic mixing valve is both incorrect and misleading.
In keeping with every other mechanism it cannot be
considered as being functionally infallible.
Malfunction of thermostatic mixing valves is almost always
progressive in nature and will be detected by the use of
proper temperature checking and maintenance routines.
Certain types of system can result in the thermostatic
mixing valve having excessive 'dead-legs' of pipework.
Others allow an auxiliary cold water supply to be added to
the mixed water from the mixing valve. Such systems can
disguise the onset
malfunction.
* Pressure Loss Ratio is determined by subtracting the
resistance of the outlet pipework and outlet fittings from the
dynamic pressures of the hot and cold water at the inlets
of the mixing valve. This is at its extreme when the mixing
valve is used at its lowest flow-rate and when the
maximum inequality occurs in the pressure of the hot and
cold water supplies.
Temperature
Minimum Cold Water Temperature: 1°C
Maximum Hot Water Temperature: 85°C
Maximum temperature of 25°C pre-set at the factory to suit
requirements; due to conditions it may vary.
Flow Rates
Maximum Flow Rate: 120 l/min

Specification

Pressures
Minimum Dynamic Supply Pressure: 0.1 bar
Maximum Dynamic Pressure: 8 bar
Maximum Supply Static Pressure: 10 bar
Maximum pressure loss ratio*: should not exceed 10:1 in
favour of either supply during flow.
1290447-W2-A
General
Safety
of thermostatic mixing

Troubleshooting

Maximum pressure loss: inlets to outlet is 5.6 bar, which
equates to maximum 120 l/min flow rate at mid blend.
Note! Pressure loss is the pressure drop between the
inlets and the outlet of the mixing valve when flow is taking
place.
Only hot or cold water from outlet
a. Inlet supplies reversed (i.e. hot supply to cold inlet).
Check.
b. Check filters and inlet fittings for blockage.
Fluctuating or reduced flow rate
a. Check filters and inlet / outlet fittings for flow restriction
(check isolators are fully open).
b. Ensure that minimum flow rate is sufficient for supply
conditions.
c. Ensure that dynamic inlet pressures are nominally
balanced.
d. Ensure that
sufficient.
No flow from mixing valve outlet
a. Check inlet isolators are fully open.
b. Check filters and inlet / outlet fittings for blockage.
valve
c. Hot or cold supply failure.
For full instructions, see Product Manuals on the
website at www.radacontrols.com
4
inlet temperature differentials are