DHW METHODS HeatNet Control V3
Page 39
setting is the maximum tank temperature. Setting
the SHED BOILER DELAY TIME correctly will
limit the maximum tank temperature to the
(DHW SETPOINT + UPPER BAND). Setting
the SHED BOILER DELAY TIME = 0 will shut
off all boilers immediately once the (DHW
SETPOINT + UPPER BAND) is exceeded.
8. Change the DHW Priority menu item PUMP
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.
This time includes the DHW post purge of the DHW
pump/valve.
9. Go to the POST PURGE menu item. This is the time
that the DHW pump relay remains energized after the
DHW SETPOINT has been satisfied. Once the tank
has exceeded the DHW SETPOINT + UPPER BAND
temperature and this DHW boiler has shut off (DHW
SHED BOILER DELAY TIME), the post purge time
will begin.
10. Now, go to USE SENSOR Select YES. This will
allow the boiler to control the tank or DHW loop
temperature using the DHW sensor. The upper
and lower band temperatures will also be loaded
when set to YES.
11. The next menu is the SHARING menu. Sharing
determines what happens when a DHW boiler is needed
and none are available (all boilers are running in space
heating and DHW heating). This means the MASTER
needs to steal a space heating boiler that is running or
no more boilers can fire in DHW.
OFF Is first come first serve. If a Boiler is not available
because all boilers are firing a space heating
demand, the DHW firing algorithm waits until
one becomes available. If a space heating boiler is
needed, a DHW running boiler cannot be stolen
for space heating. Priority goes to the first
demand present.
CYCLE The DHW algorithm can steal a space heating
boiler and fire it as a DHW boiler. The space
heating boiler stops and then restarts as a DHW
boiler. DHW has Priority.
NO CYCLE The DHW algorithm can steal a boiler that is
already running as a space heating boiler. It does a hot
swap, engaging the DHW pump/valve and leaving the
local pump running or shutting it off. Use this in
conjunction with the LOCAL PUMP OFF: and the
LOCAL DELAY: settings. DHW has Priority.
12. Next is the LOCAL PUMP OFF menu. When a DHW
heating cycle begins, the function of the local
pump/valve is determined:
NO The local pump/valve will remain running during
DHW heating.
YES The local pump will shut off with a delay
determined by LOCAL DELAY: seconds. This
allows the DHW pump/valve to prove before
shutting off the local pump.
Piping of the system will determine which setting to
use.
13. Go to the PURGE TO menu. After a DHW cycle
completes, the pump/valve can be selected to either
purge to the TANK, or to the SPACE for the duration
of the post purge time. This selection can use the space
to dump the heat from the boiler and not overheat the
DHW tank/load.
14. Set the HYB SENSOR = OFF. This sensor is
selectable for Method 5A only.
15. Finally, go to the BOILER MODE menu. If JPS1 has
not been cut, the selection will appear grayed out. Cut
JPS1. Once this is done, set the BOILER MODE to
COMBINATION. The MASTER boiler will control
the temperature in the tank using as many boilers as it
has available on H-Net along with any space heating
needs. The boilers must be piped appropriately for this
method to function correctly.
Now set up the MEMBER boiler(s).
BOILER MODE Set to COMBINATION on
MEMBER boilers, the MASTER is optional,
though it will control MEMBER DHW heating.
DHW SETPOINT This does not need to be set on
MEMBER boilers, only the MASTER boiler.
LOWER BAND This does not need to be set on
MEMBER boilers, only the MASTER boiler.
UPPER BAND This does not need to be set on
MEMBER boilers, only the MASTER boiler.
PUMP PRIORITY This does not need to be set on
MEMBER boilers, only the MASTER boiler.
POST PURGE This needs to be set on all boilers. All
boilers control their respective DHW pump/valve
when they are called to perform DHW heating.
SHARING This can be set on any boiler and will
determine how boilers will cycle on/off when they
are called to perform DHW Heating.
LOCAL PUMP OFF This can be set on any boiler to
determine how the local pump/valve behaves
when called to perform DHW heating.
PURGE TO This does not need to be set on MEMBER
boilers, only the MASTER boiler.
HYB SENSOR: = OFF. This sensor is selectable
for Method 5A only.
JPS1 MUST be cut on all boilers
providing DHW. Cutting JPS1 limits to
maximum temperatures to 200F.
To Next Page
Loading...
Need help?
General
