DORCHESTER DR-FC 120, Installation, Comissioning And Maintenance Instructions

Page: 55 / 100

Instruction manual DR-FC 53
gis
9 Starting the water
heater
9.1 Introduction
This chapter covers the following topics:
•
Starting the water heater .
• Water heater operating cycle .
9.2 Starting the water heater
Start the water heater as follows:
1. Fill the water heater
(5 "Filling") .
2. Open (3.5 "Installation diagram") the manual gas
valve.
3. Switch on the power to the water heater using the
isolator between the water heater and the power
supply.
4. Switch the controller ON by setting the ON/OFF
switch to position I .
The display will now show
INTERNAL CHECK
for
about 10 seconds, and will then go to the main
menu.
5. Press once on the blue arrow ( ) to position the
cursor beside
ON
, then press . The
display shown in the figure will appear.
6. Confirm the selection
START OPERATION
with
.
The water heater is now in "ON mode". If there is
a heat demand, the water heater will run through
the operating cycle
(2.3 "Water heater operating
cycle") .
If the operating cycle is not run, then there is no
heat demand; should this happen, then Tset will
probably need to be set
(11.4 "Setting the water
temperature") .
9.3 Water heater operating cycle
The water heater's operating cycle is activated when
the measured water temperature (T
1
) falls below the
threshold value (T
set
). This threshold value depends
on the currently selected water heater operating
mode. For example, if the water heater is in "OFF
mode" (frost protection), then this value is 5
o
C. If the
water heater is in "ON mode", then this threshold value
is selectable, for example, 65
o
C.
The operating cycle runs successively through the
following states:
1. HEAT DEMAND
2. PRE-PURGE;
3. PRESSURE SWITCH;
4. PRE-GLOW;
5. IGNITION
6. RUNNING;
7. POST-PURGE.
The entire cycle is explained in the following example,
which assumes the water heater is in operating mode
ON
.
Note
The same operating cycle applies to the other
operating modes.
INTERNAL CHECK
MENU
»OFF
^ ON
È WEEK PROGRAM
»START OPERATION
^ CHANGE SETPOINT
È Tset=65ÉC
a
a
a