A.O. Smith BTH 120 - 250 warranty Water Line Connections Heater Wiring, Closed System

Models: BTH 120 - 250

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WATER LINE CONNECTIONS

HEATER WIRING

This manual provides detailed installation diagrams (see back section of this manual) for typical methods of application for the water heaters.

The water heater may be installed by itself, or with a separate storage tank. When used with a separate storage tank, the circulation may be either by gravity or by means of circulating pump. When a circulating pump is used, it is important to note that the flow rate should be slow so that there will be a minimum of turbulence inside the heater.

CLOSED SYSTEM

CAUTION

A closed system will exist if a check valve (without bypass), pressure reducing valve (without bypass), or a water meter (without bypass) is installed in the cold water line between the water heater and street main (or well).

Excessive pressure may develop causing premature tank failure or intermittent relief valve operation. This type of failure is not covered by the limited warranty. An expansion tank or a similar device may be required in the inlet supply line between the appliance and the meter or valve to compensate for the thermal expansion of water under supply pressure.

If a water heater is installed in a closed water system, check local codes or contact the water supplier or local plumbing inspector on how to control this situation.

IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THE APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED WITH 105°C WIRE OR ITS EQUIVALENT, EXCEPT IN THE BURNER HOUSING. IN THIS CASE USE 200°C WIRE.

THE COMPUTER CONTROL REQUIRES A SOURCE OF STABLE CLEAN ELECTRICITY FOR PROPER OPERATION. INSTALLING THE HEATER ON A BRANCH CIRCUIT THAT HAS ELECTRONIC NOISE, IS SUBJECT TO FLUCTUATIONS IN VOLTAGE LEVEL OR HAS AN APPLIANCE WHICH GENERATES EMF OF RFI INTERFERENCE CAN CAUSE THE CONTROLLER TO MALFUNCTION. A HIGH QUALITY POWER CONDITIONER MUST BE INSTALLED IF THE ABOVE CONDITIONS EXIST. MALFUNCTIONS CAUSED BY A POOR ELECTRICAL SUPPLY ARE NOT COVERED UNDER YOUR WARRANTY.

The controller is wired to the heater as shown in figures 16 & 17. The model and rating plate provides the electrical information needed to size the complete heater branch supply.

All electrical work must be installed in accordance with the National Electrical Code and local requirements.

When installed, the appliance must be electrically grounded in accordance with local codes or, in the absence of local codes, with the National Electrical Code, ANSI/NFPA 70.

DO NOT ENERGIZE THE BRANCH CIRCUIT BEFORE THE HEATER TANK IS FILLED WITH WATER.

NOTE: This controller is Polarity Sensitive. If the Hot and Neutral Supply Voltage is reversed, the controller will not sense flame. Verify polarity before connecting the unit.

BSR BOARD (BTH - 250 ONLY) FIGURE 16

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A.O. Smith BTH 120 - 250 warranty Water Line Connections Heater Wiring, Closed System, BSR Board BTH 250 only Figure