ECOFEL BOILER SERVICE MANUAL
6.11 Limit Thermostat:
It is mounted on main heat exchanger outlet pipe via a clip.
It prevents damage to the boiler due to overheat. Limit thermostat
shuts down the boiler when water temperature at main heat exchanger
outlet reaches 102ºC (±4ºC). When the water temperature cools
down to 80ºC ± 12ºC, boiler should be reset for restarting. It is an
automatic reset thermostat. It is bimetal type.
6.12 NTC Sensor:
First one is used for measuring heater water temperature on the main heat
exchanger outlet pipe. The second one is located on the hot usage water
outlet of plated type heat exchanger.
NTC (Negative Temperature Control) Sensor is a thermistor, resistance
value of which falls down with the increase in temperature.
Modulation circuit is based on the adjusted resistance value of the usage
water or heater circuit temperature adjustment button. After comparing the
adjusted value with the reading of the NTC sensor (depending on the supply
voltage passing over) the information is transmitted to the main card; based
on this information main card changes the voltage value of the gas valve
coil providing modulation. To sum up, when there is an increase in water
temperature, voltage value of the gas valve coil falls down and gas valve reduces
the gas pressure in burner through modulation.
Heater NTC Sensor
Usage water NTC Sensor
6.13 Flow Control Switch and Mechanism:
Its function is to sense usage water demand. It will start to rotate
a wheel according to the water flow rate at usage water inlet when
water flow begins (hot usage water tap is opened) and at least
2.7 l/min water begins to pass. The rotation of the magnetic field
above this wheel is detected by the sensor located at the top and
transmitted to the main card after converting to frequency. In this
way, the frequency transmitted to the main card and the quantity
of water flowing from the tap is determined, thus reaching the
desired temperature of usage water with ±1ºC accuracy.
There is a gauze filter at the cold water inlet, protecting the flow
switch against piping dirt.
6.14 Filler Valve:
Provides connection between heater circuit and usage water
circuit. By the help of this valve, water can be filled in the heater
system from the mains.
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Revision Date: 29 February 2008, Rev. No: 0
TEMPERATURE
(ºC)
RESISTANCE
(kΩ)
0
27
10
17
20
12
25
10
30
8
40
5
50
4
60
3
70
2
80
1.5
