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Matrix Installation and Operation Instructions
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.
7.2.1 Instantaneous DHW (w/o Storage Tank)
The Matrix will provide domestic hot water continuously when flow is sensed by the flow meter. 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 7.1 for installation details.
DHW Limitations:
As the Matrix produces domestic hot water instantaneously; there are inherent limitations of the system:
o
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 Table 7.1 and “Procedure for Setting up Domestic Hot Water”.
o
DOESN’T MAINTAIN TEMPERATURE – When there is no call for domestic 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 9.2.1 for setting). 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 7.2), this feature should be disabled, e.g. set to OFF.
