OPTIONAL FEATURES
HeatNet Control REV 1.38-1
Page 29
above the setpoint temperature. Care should be
taken here.
9.
Press the DOWN arrow again and the menu item:
DHW
MASTER?
,
will be displayed. If this item is
set to
YES,
once the DHW MASTER receives a
HEAT DEMAND signal, it will call other boilers
it has available using H-Net. Setting to
NO
,
requires no Heat Demand signal, and will only
enable the single boiler when the DHW Tank
Temperature drops below (DHW SETPOINT –
DHW DIFF).
DHW MASTER? YES is to be only be used
WITHOUT a Header Sensor
10.
Finally, go to
DHW BOILER?
. Select
YES
. If
JPS1 has not been cut, a message will appear
instructing to do so. Once this is done, the stand
alone boiler will control the temperature in the
tank, or the DHW Master will control the
temperature in the tank using as many boilers as
it has available on H-Net.
DHW BOILER?
Does not need to be set to
YES
on MEMBER boilers, only the DHW
MASTER or on a stand alone boiler
providing DHW.
JPS1 MUST be cut on all boilers providing
DHW.
DHW METHOD 1b: Combo DHW and Space
Heating using a MASTER Boiler and Member
boiler(s) employing H-Net
This method utilizes a 10k thermistor connected to the DHW
Sensor input of a MASTER boiler, a DHW tank AND a
HEADER sensor. This Method works the same as DHW
METHOD 1a, but also has the ability to provide space
heating.
Setting up the DHW portion of this method is done via the
menus in:
SETUP:DOMESTIC HOT WATER
.
For
information on setting up the space heating portion of the
method Refer to
Heat Demand Control Method 1
located in
the CONTROL METHODS section on page 22.
1.
Connect a
10k thermistor from the DHW tank’s
sensor well to J10B terminals 1 & 2 on the
MASTER, and connect a Header Sensor to the
SYSTEM HEADER input. Wire any pump or
valve from the DHW Pump relay (normally open)
contact to control flow of the heating water into
the tank’s coil.
2.
Next, enter the
DOMESTIC HOT WATER
menu.
When prompted for
DHW BOILER?
, enter
NO
.
We will enter
YES
when we are finished entering
all parameters
3.
Change the
DHW SETPOINT
to the desired
target temperature of the water in the tank. Once
the control determines there is a call for DHW,
the DHW SETPOINT is loaded and the Master
boiler will target this new setpoint.
4.
Now, change the
DHW DIFF
to the desired
differential. This setting corresponds to the
minimum water temperature required in the tank.
DHW heating will be initiated when the DHW
tank’s water temperature is below the
DHW
SETPOINT – DHW DIFF
.
5.
Since the same the
ADD BOILER DELAY
time
is used for space heating and DHW, how long
the temperature of the tank stays below the
(DHW SETPOINT – DHW DIFF)
has to be
considered when setting the
ADD BOILER
DELAY
.
6.
Scroll down to
USE SENSOR?
Press the
SELECT
key and select
YES,
then press the
SELECT
key again
.
This will allow the boiler to
control the tank temperature using its sensor.
7.
Press the DOWN arrow key again to position the
cursor beside the menu item
DHW PRIORITY?
.
Setting this value to YES will turn OFF the
system pump when the DHW mode is active.
Setting this value to NO leaves the system pump
on.
8.
Press the DOWN arrow again and the menu item
POST PURGE
should appear. This is the time
that the DHW pump relay remains energized after
the DHW SETPOINT has been satisfied. If there
is no HEAT DEMAND signal, once the tank has
reached setpoint all boilers will shut off, and the
post purge time will begin. If there is a HEAT
DEMAND Signal when the tank has reached
setpoint, the boilers will continue running to
provide space heating, and the DHW pump relay
will be de-energized immediately. Using the
POST PURGE time to dump the boiler’s heat into
the tank may heat the tank above the setpoint
temperature. Care should be taken here.
9.
Press the DOWN arrow again and the menu item:
DHW
MASTER?
,
will be displayed. Set it to NO
for this DHW Method.
NOTE:
This DHW Method requires no Heat
Demand signal to control the temperature in the
tank. As soon as the DHW Tank Temperature
drops below (DHW SETPOINT – DHW DIFF) a
boiler will be enabled.
NOTE:
DHW MASTER? YES is only to be
used WITHOUT a Header Sensor. When both a
Header Sensor and a DHW Tank Sensor are
installed, because it has a HEADER Sensor, the
Boiler will recognize itself as a MASTER.
When DHW BOILER? is also set to YES, the
