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P/N HN-IOM-1 82-0331 Copyright 2009 Mestek, Inc.
Finned copper tube gas boilers & water heaters – Control manual
Boiler operation and status display
8
Starting the system
Follow the Boiler manual
— Install the
boilers according to the
Boiler Installation &
Operating Instructions
manual before attempting
to set up the control system. Perform the start-up
and adjustment procedures in the manual before
proceeding. Failure to comply could result in severe
personal injury, death or substantial property
damage.
FAULTS
— Clear any faults that appear on the
display and make sure to correct the cause before
proceeding. You can silence the alarm by applying
a jumper across J10B SPARE terminals.
Place the LOCAL/REMOTE switch on the MASTER
1.
boiler (or stand-alone boiler) to LOCAL.
Place MEMBER boiler LOCAL/REMOTE switches to
2.
REMOTE.
Start the MASTER boiler first. Turn the MASTER boiler
3.
ON/OFF switch to ON.
The HeatNet control will initialize and show the standby
4.
screen unless there is a call for heat.
Start a call for heat. As soon as the control receives a call for
5.
heat, it will show the setpoint temperature bar, as below:
R U N
%
5 0
B L R S
F I R I N G
| | | | | | | | |
1 - - - - - - -
- - - - - - - -
The graphic below explains the temperature bar. You will
6.
see the header or supply temperature change as boilers add
heat to the system or demand changes.
The upper left of the display will show boiler condition
7.
(prepurge, etc.) as the boiler begins its cycle. After the boiler
begins firing, the screen will show RUN % as above.
After the ADD BOILER DELAY time has elapsed, the next
8.
boiler will fire. The MASTER boiler display will show the
START and STOP times. The START time counts down
on the display. When the next boiler starts, a 2 will shown
in the BLRS FIRING list. If this doesn’t happen, the water
temperature may have entered the HEAT BAND, so no ad-
ditional heat is needed.
Watch the temperature response as boilers are added. The
9.
HeatNet control will attempt to bring the controlled tem-
perature to the setpoint by modulating boilers to meet the
demand.
If temperature tends to overshoot too much, adjust the
10.
ADD BOILER DELAY, STOP BOILER DELAY, and
MODULATE DELAY settings in the ADVANCED SET-
UP menu to adapt behavior to the system.
Member boiler displays will show RUN % in the upper left
11.
of the display.
The AA terminals are the high fire override. If
closed on a MEMBER boiler, the boiler runs
independently of the MASTER, because AA takes
priority. If AA is closed on the MASTER boiler, the
HeatNet network shuts down, and only the master
boiler fires (at high fire). If using a diverter valve
for a DHW tank, it is recommended that you use
a MEMBER boiler, activated with its AA terminals.
This way, the HeatNet and heating loop will still be
under control.
