A.O. Smith Innovo 12-160, Installation, Service & Maintenance Manual

Page: 33 / 92

6.3 Safety devices
Fig. Safety devices
1
4
2
3
1. Temperature
sensor
2. Gas control valve
3. Air proving
switch
4. Flame probe
Safety devices of the water heater:
Temperature
sensor (1) The water heater controls the water temperature
using a temperature sensor:
T < 5 ºC, frost protection is activated.
T > 88 ºC, max. temperature.
T > 93 ºC, for extra safety. •
•
•
Gas control valve (2) The gas control valve controls the gas supply to
the burner.
Air proving switch (3) The air proving switch guarantees the air supply
differential during pre-purging.
Flame probe (4) The flame probe detects if there is a flame in the
burner.
Safety devices of the installation:
Expansion vessel The expansion vessel stores temporarily expansion
water to keep the pressure in the installation at the
right level.
Expansion valve The expansion valve prevents excessive pressure
in the tank of the water heater.
Pressure-reducing valve The pressure-reducing valve reduces the water
mains pressure, if necessary.
Temperature and
pressure relief valve
(T&P valve)
(1)
The T&P valve prevents excessive pressure and
temperature in the tank.
1 - All installations have a T&P valve connection. A T&P valve is mandatory for unvented
installations.
Note
This manual only discusses unvented installations.
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