Technical documentation
Technical documentation
STEM@ ed 06/01
5
EOLO MAIOR @
HYDRAULIC CIRCUIT
EOLO Maior 21-24-27 @
EOLO Maior 21–24 S @
1- Minimum flow shutter (*)
2- Flow limiting device (*)
3- 3-way hydraulic valve (*)
4- Gas valve
5- D.h.w. exchanger (*)
6- NTC d.h.w. probe (*)
7- Burner
8- Primary exchanger
9 - Sealed chamber
10 - Flue hood
11 - Fan
12 - Fan safety pressure switch
13- Overheat. safety thermostat
14- NTC adjustment and limit
probe
15- Automatic air vent
16- Expansion vessel
17- Circulator
18- One way valve
(*)
19- Automatic bypass
(*)
20- Bypass disengag. screw
(*)
21- 3-bar safety valve
22- System water pressure
switch
23- D.h.w. flow microswitch
(*)
24- Filling stop cock
25- One way valve
(**)
G - Gas supply
U - Hot water outlet (*)
E - D.h.w. inlet
R - System return
M - System delivery
(*) only on versions with d.h.w.
production
(**) only on version 27
PRIMARY CIRCUIT
(BOILER CIRCUIT)
The primary circuit with relevant control and safety devices is started
every time there is a central heating or
domestic hot water request
.
- OPERATION
The heat contained in the combustion products is absorbed by the copper blades of the water-gas exchanger (8),
which in turn transfers this heat to the water circulating inside thanks to the boiler pump (17).
In the case of the models for central heating only (S), the water flows directly into the system, while in the case of
boilers with d.h.w. production, this can be deviated inside an instantaneous plate exchanger (5) made of
STAINLESS steel.
This depends on the position of the 3-way hydraulic valve (3), which when idle permits flow through the system
delivery pipe (M) and return pipe (R) while, following running of the d.h.w., flow is deviated towards the d.h.w.
exchanger (5).
- CIRCULATOR
This operates on the primary circuit return and is located on
the brass header assembly.
It is connected to the enbloc by means of a threaded
connecting piece, while the primary exchanger and expansion
vessel are connected by means of coupling pipes (2) with O.R.
seal (3), locked by means of special forks (1).
The pumps used differ according to boiler output
(see head -
flow graph).
