Mira Element SLT, Installation And User Manual

20

It is a requirement that all TMV2 approved 

valves shall be verified against the original 

set temperature results once a year. When 

commissioning/testing is due the following 

performance checks shall be carried out.
Measure the mixed water temperature at the 

outlet.
Carry out the cold water supply isolation test by 

isolating the cold water to the TMV, wait for five 

seconds  if  water  is  still  flowing  check  that  the 

temperature is below 46°C.
If there is no significant change to the set outlet 

temperature (±2°C or less change from the 

original  settings)  and  the  fail-safe  shut  off  is 

functioning, then the valve is working correctly 

and no further service work is required.

Notes! 

If there is a residual flow during the 

commissioning of the valve or the annual 

verification (cold water supply isolation test), then 

this is acceptable providing the temperature of 

the water seeping from the valve is no more than 

2°C above the designated maximum mixed water 

outlet temperature setting of the valve.
Temperature readings should be taken at the 

normal flow rate after allowing for the system to 

stabilise.
The sensing part of the thermometer probe 

must be fully submerged in the water that is to 

be tested.
Any TMV that has been adjusted or serviced must 

be re-commissioned and re-tested in accordance 

with the instructions given in this guide.

The installation of thermostatic mixing valves must 

comply with the requirements of the Water Supply 

(Water Fittings) Regulations 1999.

FAULT DIAGNOSIS

If you require a Mira trained service engineer or 

agent, refer to section: 

‘Customer Services’

.

Fault Diagnosis

Symptom:

•  Only hot or cold water from the mixer outlet.
•  Outlet temperature too hot / too cold.

Cause / Rectification:

•  Inlets reversed (hot supply to cold supply).
•  No hot water reaching mixer.
•  Check the filters for any blockage.
•  Installation  conditions  outside  operating 

parameters, refer to sections: 

‘Specifications’ 

and 

‘Commissioning’

.

—————————————

Symptom:

•  Fluctuating or reduced flow rate.

Cause / Rectification:

•  Check  the  showerhead,  hose  and  filters  for 

any blockage and clean.

•  Make sure that the maintained inlet pressures 

are nominally balanced and sufficient, refer to 

section: 

‘Specifications’

.

•  Make  sure  that  the  inlet  temperature 

differentials  are  sufficient,  refer  to  section: 

‘Specifications’

.

•  Flow regulator fitted incorrectly.
•  Air lock or partial blockage in the pipework.

—————————————

Symptom:

•  Water leaking from showerhead.

Cause / Rectification:

•  Normal for a short period after shut off.
•  Check that the pressures are not in excess of 

the specifications for the product.

•  Renew the thermostatic cartridge.