Noritz N-0931M-DV Installation Manual

Also see for N-0931M-DV: Field manual Service manual

Contents

1510. Water PipingThis appliance suitable for potable water and space heating applications. Do not use this appliance if any part hasbeen underwater. Immediately call a qualified service technician to inspect the appliance and replace any part of thecontrol system and gas control which has been under water.If the water heater is installed in a closed water supply system, such as one having a backflow preventer in the coldwater supply line, means shall be provided to control thermal expansion. Contact the water supplier or a local plumb-ing inspector on how to control this situation.A pressure relief valve must be installed near the hot water outlet that is rated in accordance with and complying witheither The Standard for Relief Valves and Automatic Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22, orThe ANSI/ASME Boiler and Pressure Vessel Code, Section IV ( Heating Boilers ). This pressure relief valve mustbe capable of an hourly Btu rated temperature steam discharge of 250,000 Btuh. Multiple valves may be used. Thepressure relief capacity must not exceed 150 psig. No valve shall be placed between the relief valve and the waterheater. The relief valve must be installed such that the discharge will be conducted to a suitable place for disposalwhen relief occurs. No reducing coupling or other restriction may be installed in the discharge line. The discharge linemust be installed to allow complete drainage of both the valve and the line. If this unit is installed with a separatestorage vessel, the separate vessel must have its own temperature and pressure relief valve. This valve must alsocomply with The Standard for Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply Systems, ANSIZ21.22. (in the U.S. only). A temperature relief valve is not required, but if one is used, do not install the valve with theprobe directly in the flow of water. This may cause unwarranted discharge of the valve.Piping and components connected to the water heater shall be suitable for use with potable water.Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.A water heater used to supply potable water may not be connected to any heating system or components previouslyused with a nonpotable water heating appliance.When water is required in one part of the system at a higher temperature than in the rest of the system, means suchas a mixing valve shall be installed to temper the water to reduce the scald hazard.Installation and service must be performed by a qualified plumber. In theCommonwealth of Massachusetts, this product must be installed by a licensedplumber or gas fitter in accordance with the Massachusetts Plumbing and FuelGas Code 248 CMR Sections 2.00 and 5.00. Observe all applicable codes.• Flush water through the pipe to clean out metal powder, sand and dirt before connecting it.• Perform the following insulation measures for prevention of freezing.• Take appropriate heat insulation measures (e.g., wrapping with heatinsulation materials, using electric heaters) according to the climate ofthe region to prevent the pipe from freezing.• Make sure that there are no water leaks from the cold and hot watersupply pipes, then insulate the pipes completely.• Be sure to also completely insulate the water supply valve and thecold and hot water connections on the water heater (refer to the figureon the right).• Do not cover the water drain plug with insulation so that water in thepipe can be drained. (Refer to the figure in the right.)• Use a union coupling or flexible pipe for connecting the pipes to reduce the force applied to the piping.• Do not use piping with a diameter smaller than the coupling.• When feed water pressure is too high, insert a depressurizing valve, or take water hammer prevention measure.• Avoid using joints as much as possible to keep the piping simple.• Avoid piping in which an air holdup can occur.• If installing the unit on a roof:• About lower-level hot water supplyIf the unit is installed on a roof to supply water to the levels below, make sure that the water pressure supplied tothe unit does not drop below 29 psi. It may be necessary to install a pump system to ensure that the water pressureis maintained at this level.Check the pressure before putting the unit into operation.Failure to supply the proper pressure to the unit may result in noisy operation, shorter lifetime of the unit, and maycause the unit to shut down frequently.