Cut - Out; Mmersion Heater ( S ); Nvented Controls; Hermostats - Ariston ST 50 Instructions For Installation Manual

4.3 T C -
HERMAL UT
4.4 I H
MMERSION EATER
4.5 U C
NVENTED ONTROLS
4.5 T

HERMOSTATS

( ) If the thermal cut-out has operated the cause must be found before resetting
OUT S
(see section 5).
( ) Descale the immersion heater(s) and remove any lime deposit from the
S
cylinder. Replace in reverse order. THIS DOES NOT APPLY TO COMFORT
MODELS.
Check controls as per the following:
1) Line strainer - with the water supply turned off remove screen from
strainer and clean of any detritus;
2) Expansion vessel - with the water supply turned off and taps open, check
expansion vessel pressure and top up as necessary;
3) Temperature & pressure relief valve - with the water supply turned on,
check manually by lifting the test lever/turning the test knob (ensure valve
closes after testing);
4) Expansion relief valve - check manually by turning the test knob (ensure
valve closes after testing);
5) Discharge pipes (D1) - from both temperature & pressure relief and
expansion relief valve for obstructions;
6) Tundish & discharge pipe (D2)- open either valve gradually to produce a
full bore discharge into tundish and D2 without any back pressure;
7) Pressure reducing valve - check that the correct outlet pressure is being
maintained by recording the pressure at an in-line terminal fitting i.e. tap.
Ensure that all thermostats adjusted for the correct temperature setting, this
should be between 60 and 65°C.
20