Specifications

23
Matrix Installation and Operation Instructions
7.0 Domestic Hot Water System
7.1 Operation and Set-up
The Ma trix hea ts domestic hot water o n dema nd, indirectly, using a brazed plate heat e xchanger. When domestic water passes
through the flow switch at a flow rate greater then 0.5 GPM, the switch closes completing a 24VAC circuit between R and FS on
the Matrix terminal strip. 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 the programmed H20 setting, which represents the boiler water
temperature set point for domestic mode operation. Because the Matrix uses boiler water to indirectly heat the domestic water, via
the brazed plate heat exchanger, the H20 domestic setting must be higher then the required domestic hot water temperature (See
Section 9.2.1). To achieve a controlled domestic hot water supply temperature, NTI provides a Thermostatic Mixing Valve
adjustable from 100 to 145°F. Note, code requirements may require the maximum setting to fixed at 120°F, see “Thermostatic
Mixing Valve” below and the instructions included with the valve.
For improved domestic hot water comfort, the Matrix incorporates a “Storage” feature. This storage feature, when enabled, will
keep the boiler water hot for a period of 1 to 24 hours following a call for domestic hot water. When the boiler water drops below
140°F the boiler will fire and bring the boiler to 180°F before shutting off. This “Storage” feature helps in reducing the wait time
associated with a tankless hot water system. In systems where a storage tank is used, this feature should be disabled.
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.)
Flow Switch (Supplied): The Matrix comes with a domestic flow switch that must be field installed in the location shown. It is
important the flow switch be installed in the cold water line before the cold-water branch to the Mixing Valve or in the mixed out
line, thus the flow switch will have the total domestic hot water flow rate available to trigger it and initiate the hot water call. Dirt
and other debris can cause the flow switch to fail. Therefore it is important to install the switch in the vertical up position, as
recommended by the manufacturer. It is also recommended to install a filter (100 micron) on the incoming water if tests show
particles larger than 100 microns.
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 Valves: Install drain valves on the inlet and outlet of the brazed plate heat exchanger 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.
Cleaning: Brazed plate heat exchangers operate with high turbulence flow, even at low flow rates. This high turbulence keeps
small particles in suspension minimizing fouling and scaling. However, in some applications the fouling tendency can be very
high, e.g. when using extremely hard water at high temperatures. In such cases it is always possible to clean the exchanger by
circulating a cleaning liquid. Use a tank with weak acid, 5% phosphoric acid or, if the exchanger is frequently cleaned, 5% oxalic
WARNING
IF THE ANTI-SCALD V
A
LVE IS NOT INSTALLED TO THE HONEYWELL SHEET ‘SD/IS150’, AND THIS
MANUAL, OPERATION MAY SUPPLY SCALDING HOT WATER TO THE OCCUPANTS.