16
P/N HN-IOM-1 82-0331 Copyright 2009 Mestek, Inc.
Finned copper tube gas boilers & water heaters – Control manual
Configuring for DHW applications
5
SCALD HAZARD — Water over 125°F can
cause severe burns or death.
Provide temperature regulating, anti-scald devices in DHW
supply piping to fixtures to prevent possibility of severe injury
or death due to scalding.
DHW options
The HeatNet control allows four options for providing DHW
heating. These are:
Method 1 —
❑
A tank-temperature sensor
, connected to
the DHW Sensor input allows direct control of tank tem-
perature. Method 1 can be used for combined space heat-
ing/DHW systems.
This control method is designed to limit tank temperature
to a specified maximum. It can cause short cycling in some
cases. If the tank temperature can be allowed to vary above
and below a setpoint temperature and the application is
DHW heating only, you can use method 3 instead.
Method 2 — A
❑
tank temperature aquastat
in the tank
turns one boiler on and off on demand. Method 2 can be
used on combined space heating/DHW systems.
Method 3 —
❑
A tank-temperature sensor
, connected to
the Header sensor input of the master boiler allows direct
control of the tank temperature. The firing and sequencing
of boilers operates just as when used space heating applica-
tions. This method is limited to dedicated DHW systems.
Method 4 —
❑
4–20 ma remote controller
. This can be ap-
plied for a single boiler (or single member boilers) or for all
boilers of a network.
