24
In-Service Testing
Commissioning and In-Service Tests
D.1. Commissioning
D.1.1 Purpose
Since the installed supply conditions are likely to be different
from those applied in the laboratory tests it is appropriate, at
commissioning, to carry outsome simple checks and tests on
each instantaneous water heater to provide a performance
reference point for future in-service tests.
D.1.2 Procedure
D.1.3
With the appliance turned off check that:
a) The designation of the appliance matches the intended
application.
b) The water supply temperature is within the range 5 to
20ºC.
c) The terminal voltage at the appliance is within the range
230
±
10%.
D.1.4
Turn on the appliance and if the maximum outlet water
temperature is adjustable, adjust this in accordance with the
manufacturer’s instructions to the maximum permitted for
the application. Then carry out the following sequence;
a) Record the supply voltage at the terminals of the
appliance;
b) Record the outlet water temperature and the flow rate
resulting from the setting;
c) Reduce the water supply flow rate at the inlet of the
applianceby at least 50% or to the lowest value at which
the appliance continues to deliver an output of heated
water, whichever is the greater;
d) Record the outlet water temperature and the reduced;
The outlet water temperature should not exceed 43ºC
for a shower.
e) Record details of the equipment, thermometers etc.
used for the measurements.
D.2. In-Service Tests
D.2.1 Principle
The purpose of in-service tests is regularly to monitor and
record the performance of the instantaneous water heater.
Deterioration in performance can indicate the need for
service work on the appliance and/or the water supplies.
D.2.2 Procedure
Commissioning and In-Service Tests
D.2.3
Using the measuring equipment recorded in D1.4 or
equipment to the same specification and with the appliance
turned off check that:
a. The water supply temperature is within the range 5 to
20ºC;
b. The terminal voltage at the appliance is within the range
230
±
10%
D.2.4
If the set maximum outlet water temperature has
changed significantly from the previous test results
(e.g. > 1 K), record the change and before re-setting the
maximum outlet water temperature check:
a) That the outlet fittings are not blocked and are free of
scale;
b) That any in-line or integral strainers are clean;
c) Any in-line or integral check valves or other backflow
prevention devices are in good working order;
d) Any isolating valves are fully open.
D.2.5
With an acceptable outlet water temperature, complete
the following procedure:
a) Record the supply voltage at the terminals of the
appliance;
b) Record the outlet water temperature and the flow rate
resulting from the setting;
c) Reduce the water supply flow rate at the inlet of the
appliance by at least 50% or to the lowest value at which
the appliance continues to deliver an output of heated
water, whichever is the greater pressure;
d) Record the outlet temperature and the reduced flow
rate;
NOTE:
The outlet water temperature should not exceed 43ºC
for a shower.
e) Record details of the equipment, thermometers etc.
used for the measurements.
D.2.6
If at step D.2.5 b) the outlet water temperature is
greater than the values given in the note to D.2.5 d) then
service work is indicated.
D.3 Frequency of in-service tests
D.3.1 General
In-service tests should be carried out with a frequency
which identifies a need for service work before an unsafe
water temperature can result. In the absence of any other
instruction or guidance on the means of determining the
appropriate frequency of in-service testing, the following
procedure may be used:
Need help?
Give us a call on
0844 701 6273
and speak to one of our trained advisors.