RBI Dominator Series Installation & Operating Instructions Manual

RBI Dominator Series Installation & Operating Instructions Manual Manual pdf 18 page image

Fi d b b il & h B il M lFinned copper tube gas boilers & water heaters – Boiler Manual18FFDOMESTIC WATER SUPPLY PIPINGProper control settings must be used to prevent watersupplied for domestic use from exceeding 130°F, 54°Cor a scald injury will occur! When higher watertemperatures are required for appliances such as adishwasher, a mixing valve or some other temperingmeans must be installed. Households with smallchildren may require water temperatures less than120°F, 49°C. Local codes must be complied with!General Piping RequirementsEnsure that the water heater is equipped with bronze headers. Pipingand components connected to the water heater must be suitable for usewith potable water. The water heater must not be connected to anyheating system piping or components previously used with a non-potable water heating appliance. No toxic chemicals, such as those usedfor boiler treatment, are to be introduced into the potable water usedfor space heating. If a hot water storage tank is used in the system it mustbe equipped with a temperature and pressure relief valve that complieswith ANSI Z21.22 or CAN-4.4 and CAN-4.6.Th e storage tank must be located as close to the waterheater as possible to prevent excessive head loss whichwill reduce fl ow.Water ChemistryThe required temperature rise across the water heater is based onwater having a hardness between 8 and 18 grains per gallon with alevel of dissolved solids not exceeding 350 ppm. Water having ahardness less than 8 grains can cause excessive errosion of the heatexchanger. Water that has a hardness greater than 18 grains per gallonand/or a level of dissolved solids exceeding 350 ppm will require arecalculation of the pump size and temperature rise.A cupro-nickel heat exchanger may also be required. The manufacturershould be consulted when these water conditions are encountered.See Table 8A.Th e maximum allowable fl ow rate through a Dominatorwater heater with copper heat exchanger is 105 GPM,6.6 L/s. The cupro-nickel heat exchanger allows for120 GPM, 7.6 L/s, see Table 8B.RBI water heaters are designed to run scale free. Due to the extremevariables of water conditions world wide it is necessary to considerpH values and water hardness in relationship to scaling. It is crucialto consider these two variables when making heat exchanger andpump selection. If local water conditions are extreme follow theguidelines in the Heat Exchanger Selection Table (Table 8A) and thePumping Performance Table (Table 8B). Scale free operation can beachieved by using water with a hardness between 8 and 18 and bymaintaining the pH between 5 and 9. Follow the conditions listedunder NORMAL in the table. In some areas of the country additionalprecautions must be observed due to unusual characteristics of thelocal water supply. Call the nearest RBI representative for details.To properly size the pump a grain hardness and pH test must be takenat the installation site before the order is placed. Proper pump sizingwill improve heater performance and help ensure heater longevity.