NTI Matrix Installation And Operation Instructions Manual page 36

Installation and Operation Instructions
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 acid. Pump the cleaning liquid
through the exchanger. For optimum cleaning, the cleaning solution flow rate should be a minimum of 1.5
times the normal flow rate, preferably in a back-flush mode. After use, do not forget to rinse the heat
exchanger carefully with clean water. A solution of 1-2% sodium hydroxide (NaOH) or sodium bicarbonate
(NaHCO3) before the last rinse ensures that all acid is neutralized. Clean at regular intervals.
Instantaneous DHW (w/o Storage Tank)
The Matrix will provide domestic hot water continuously when flow is sensed by the flow sensor. This method is
the most efficient means of heating water by allowing the boiler to operate at a lower return water temperature,
thus increasing combustion efficiency, and by minimizing standby losses. See Figure 11-1 for installation details.
DHW Limitations – As the Matrix produces domestic hot water instantaneously; there are inherent limitations of
the system:

NO STORAGE - As there is no water storage, the boiler can only provide water at the temperature
specified at the corresponding flow rates. Flow through the fixtures must be regulated so not to exceed
the ability of the boiler to heat the water. MORE FLOW = LESS TEMPERATURE. See "Procedure for
Setting up Domestic Hot Water" and Table 11-1.

DOESN'T MAINTAIN TEMPERATURE – When there is no call for domestic hot water, the unit is off.
From a dead stop the unit will detect flow and start providing heat in 15 seconds, and be up to capacity
by 25 seconds. Once running, the unit can provide an endless amount of hot water. If the flow is
momentarily turned off for whatever reason, the unit will turn off. Once off, the unit must relight, and not
provide heat for 45-75 seconds. This will cause cold unheated water to pass through the unit, and
advance through the domestic plumbing between the previously heated (hot) water, and the new (hot)
water. This can be mistaken for an inability to adequately heat the water.
"Storage" Feature (St0) – 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 (See Section 13.0 for further information of setting control). 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 (See Figure 11-2), this feature should be disabled, e.g. set to OFF.
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Matrix