8
TMV3 ART 33 Screwed Rev 1
Note 1
• 46°Cisthemaximummixedwatertemperaturefromthebathtap.Themaximum
temperature takes account of the allowable temperature tolerances inherent in
thermostaticmixingvalvesandtemperaturelossesinmetalbaths.Itisnotasafebathing
temperature for adults or children.
• The British Burns Association recommends 37 to 37.5°C as a comfortable bathing
temperatureforchildren.InpremisescoveredbytheCareStandardsAct2000,
themaximummixedwateroutlettemperatureis43°C.
8. Maintenance & In-Service Testing
• The purpose of in-service testing is to regularly monitor and record the performance of the
thermostaticmixingvalve.Deteriorationinperformancecanindicatetheneedforservice
workonthevalveand/orwatersupply.
• Carry out the test sequence using the same or equivalent equipment used for
commissioning the valve.
• Ifthemixedwatertemperaturehaschangedsignicantlyfromtheprevioustestresults
(e.g.>1°C),recordthechangeandbeforere-adjustingthemixedwatertemperaturecarry
out the following checks;
• Allin-lineorintegralltersareclean.
• Any in-line or integral non-return valves or other anti-back siphonage devices are in
good working condition.
• Any isolation valves are fully open.
• Withanacceptablemixedwatertemperature,completethetestsequenceaspersection7
of this document.
• Intheabsenceofanyotherinstructionorguidance,itisrecommendedthatIn-Service
Testsarecarriedoutasperthetablebelow.Ifthetemperatureisoutsideoftheexpected
range it will be necessary to remove and clean the valve in accordance with the
instructions in the table below: -
Temperature Variation (°C) Comment Service Frequency (Weeks)
+/-1°C N/A 24 – 28 Weeks
+/-1°C–2°C In either one period 24 – 28 Weeks
+/-1°C–2°C In both periods 18 – 21 Weeks
+/-Exceed2°C In either period 18 – 21 Weeks
• Ifthereisaresidualowduringthecommissioningorbi-annualverication(cold
water supply isolation test) then this is acceptable providing the temperature of the water
seepingfromthevalveisnomorethan2°Cabovethedesignatedmaximummixedwater
