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Matrix Installation and Operation Instructions
7.0 Domestic Hot Water System
7.1 DHW Description of Operation
The Matrix heats domestic hot water on demand, indirectly, using a brazed plate heat exchanger. Using an internal flow meter, the
Matrix recognizes a DHW demand when the DHW flow rate is greater then 0.4gpm. The Matrix immediately goes into domestic
mode, regardless of what other systems may have been operating, the burner fires and the Matrix attempts to achieve a calculated
set point which depends on the sensed water flow rate and the programmed H20 setting (See Section 9.2.1). The H20 setting is
accessed via the menu in the Matrix Fan (blue) controller, and should be set at a value equal to (or slightly greater) than the
temperature required at the hot water fixtures, e.g. 125ºF. The Fan control will communicate to the Boiler (red) controller a boiler
water temperature set point applicable for the sensed flow rate and the H20 setting selected. The higher the flow rate and/or H20
setting, the higher the boiler water set point (boiler water setting will not exceed the H20 setting by more then 30ºF). NTI provides
a Thermostatic Mixing Valve adjustable from 100 to 145°F; the mixing valve shall be installed between the Matrix DHW supply
fitting and the hot water supply pipe to the fixtures (See Figures 7.1 and 7.2), thus providing user protection from scalding hot
water. Note: code requirements may require the maximum setting to be fixed at 120°F, see “Thermostatic Mixing Valve” below
and the instructions included with the valve.
7.2 DHW System Plumbing & Set-up
DHW Inlet & Outlet Connections:
The Matrix has two potable water connections, Inlet & Outlet, which exit the left side of
the Matrix Cabinet; on the inside of the cabinet the two lines are connected to the Brazed Plate Heat Exchanger. The cold Inlet line
flows through an integrated brass flow meter before connecting to the rear fitting of the Brazed Plate Heat Exchanger. The hot
Outlet line flows directly from the front fitting of the Brazed Plate Heat Exchanger. See Figures 7.1 and 7.2 for installation details
Thermostatic Mixing Valve:
A Sparcomix AM101-US-1 is provided with your package. This valve regulates the water
temperature leaving the plate heat exchanger, and must be used in every instance. The dial can be set to the desired temperature
required. Consult the Honeywell manual
SD/IS150
for detailed instructions and settings
. (Note: the valve must be set to a supply
temperature of not more then 120˚F. It is the responsibility of the installer to set the valve and remove the dial.)
Y-Strainer (Supplied):
To protect the Matrix’s internal flow meter, it is important to install the factory supplied Y-Strainer in
the location shown in Figures 7.1 and 7.2; dirt and other debris can cause the flow meter to malfunction.
Check Valve:
A check valve must be field provided and installed on the outlet of the mixing valve to prevent expansion devises
down stream from back flowing when the water pressure drops during cold water draws. Failure to prevent the backflow will cause
water to flow forward through the flow switch, activating it, when the cold-water draw has ended and the water pressure increases.
Throttling Valve:
Installed a throttling valve, after the mixing valve, to regulate the maximum hot water flow rate. The Matrix is
limited to a firing rate of 150MBH; therefore excessive flow rates will result in cooler hot water temperatures.
Drain and Isolation Valves:
Install drain and isolation valves on the inlet and outlet of the brazed plate heat exchanger, as
shown in Figures 7.1 and 7.2 so it can be flushed free of possible build-up caused by dirt or hard water.
Hard Water:
To prevent the formation of scale on the inside of the brazed plate heat exchanger and other components in the
domestic hot water system, water with hardness higher than 50 ppm Calcium Carbonate must be treated with a “Water Softener”
prior to entering the appliance. Plugging of the domestic system by scaling or accumulation of dirt is not the responsibility of NY
Thermal Inc., and suitable steps shall be taken to avoid it.
WARNING
IF THE ANTI-SCALD VALVE IS NOT INSTALLED TO THE HONEYWELL SHEET ‘SD/IS150’, AND THIS
MANUAL, OPERATION MAY SUPPLY SCALDING HOT WATER TO THE OCCUPANTS.
