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BTR TANK TYPE HEATERS SERVICE HANDBOOK BTR HANDBOOK TABLE OF CONTENTS PAGE PAGE Troubleshooting (continued) Introduction 1-2 Troubleshooting the Efflkal 30-31 Wire Harness Test 32 Installation IID Module 33 Clearances 3-4 Pilot Spark 34 Air Requirements 5-9 Pilot Valve 35-36 Contaminated Air 10 Main Burner Test 37 Flammable 10 Flame Rectification 38 Gas Pressure 11 IID Module 39 Gas Valve 12 Main Gas Valve 40-41 Venting 13-15 Wiring Schematics Natural and Propane Gas 42 Sequence of Operation Mec
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BTR TANK TYPE HEATERS SERVICE HANDBOOK Qualifications: Installation or service of this water heater requires ability equivalent to that of a licensed tradesman in the field involved. Plumbing, air supply, venting, gas supply and electrical testing skills are required. Tools Required: • Phillips head screwdriver • standard screwdrivers • a 3/8 and 7/16 inch open end wrench • setofmarkeddrillbits • an electrical multimeter tester capable of measuring continuity • gas pressure gauge or manometer (g
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BTR TANK TYPE HEATERS SERVICE HANDBOOK INSTALLATION This portion of the handbook will review some often overlooked installation considerations, taking note of necessary installation requirements for the BTR 120 through 500 model heaters. The installation manual covers most of these items in detail. CLEARANCES FROM COMBUSTIBLES Clearance to Combustibles Table MODEL A B C 120 - 200 1” (2.54CM) 1” (2.54CM) 1” (2.54CM) 250 - 305 2” (5.08CM) 2” (5.08CM) 2” (5.08CM) 365 - 500 3” (7.75CM) 3” (7.75CM) 3
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BTR TANK TYPE HEATERS SERVICE HANDBOOK EXTERIOR CLEARANCE "Copyright by the American Gas Association. Used by permission of the copyright holder". This illustrates the exterior roof clearances for BTR units with natural draft venting. The vent shall extend at least 3 feet above the highest point where it passes through a roof of a building, and at least 2 feet higher than any portion of a building within a horizontal distance of 10 feet (for vents of 12" in diameter or less). (NFPA 54 ANSI Z 223
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BTR TANK TYPE HEATERS SERVICE HANDBOOK AIR FOR COMBUSTION 10 CUBIC FEET OF AIR PER 1,000 BTU 10 CU. FT. COMB. AIR 1,000 1,000 1,000 + BTU BTU BTU 2.5 CU. FT. EXCESS AIR Stoichiometric or theoretical complete combustion requires 10 cubic feet of air per 1000 BTUH input of the gas input. The National Fuel Gas Code also recommends an additional 2.5 cu.ft. of "excess" air. This 12.5 cu.ft minimum supply air per 1000 BTUH input applies to natural and propane gas models. The National Fuel Gas Code als
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BTR TANK TYPE HEATERS SERVICE HANDBOOK MAKE-UP AIR DIRECT COMMUNICATION 1 Square Inch Per 4,000 BTUH A fresh supply of make-up air for combustion can be supplied to the heater through make-up air ducts which directly communicate with the out of doors. Two openings are required - one within 12 inches of the top of the enclosure and one within twelve inches of the bottom of the enclosure. Each opening shall have a free area of not less than 1 square inch per 4000 BTUH of the total input of all app
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BTR TANK TYPE HEATERS SERVICE HANDBOOK MAKE-UP AIR VERTICAL DUCTS 1 Square Inch Per 4,000 BTUH Often it is more practical to install vertical make-up air ducts to the out doors. Again, two openings are required - one within 12 inches of the top of the enclosure and one within twelve inches of the bottom of the enclosure. Each opening shall have a free area of not less than 1 square inch per 4000 BTUH of the total input of all appliances within the enclosure. A.O. Smith Water Products Service Han
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BTR TANK TYPE HEATERS SERVICE HANDBOOK MAKE-UP AIR HORIZONTAL DUCTS 1 Square Daily Schedule Inch Per 2,000 BTUH When the heater is installed in an interior room with no roof access for vertical ducts, horizontal make-up air ducts should be installed. When using horizontal ducts, two openings are required - one within 12 inches of the top of the enclosure and one within twelve inches of the bottom of the enclosure. Each opening shall have a free area of not less than 1 square inch per 2000 BTUH o
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BTR TANK TYPE HEATERS SERVICE HANDBOOK INSUFFICIENT MAKE-UP AIR BACKDRAFT Insufficient make-up air is a major cause of combustion problems. One common example is in a restaurant installation where exhaust vent equipment was not considered in sizing make-up air requirements. This may result in air being backdrafted by the restaurant exhaust equipment through the heater causing flue gas spillage, flame roll out, improper combustion, inconsistent pilot operation, and/or erratic heater shut down. A.
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BTR TANK TYPE HEATERS SERVICE HANDBOOK CONTAMINATED AIR Along with adequate make-up air, the quality of the air is important. Contaminants in combustion air can lead to premature heater failure. Vapors from bleaches, soaps, waxes, salts, etc. are drawn into the combustion chamber with the make-up air and, once fired, mix with water vapor in the gases to form extremely corrosive hydrochloric or hydrofluoric acid and other corrosive byproducts. AIR FOR COMBUSTION Flammable Items Flammable items, p
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BTR TANK TYPE HEATERS SERVICE HANDBOOK GAS PRESSURE REQUIREMENTS Supply Gas Manifold Pressure Tap Dirt Leg Manifold Gas Port Natural Gas Propane Gas Maximum Supply Pressure 13.8" w.c. 13.8" w.c. Minimum Supply Pressure 4.5" w.c. 11" w.c. Manifold Pressure 3.5 " w.c. 10" w.c. The supply gas pressure is normally measured at the dirt leg or at the gas pressure tapping on the gas supply shutoff valve. This reading must be measured with 'flowing' gas. The manifold gas pressure is measured at the mani
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BTR TANK TYPE HEATERS SERVICE HANDBOOK BTR GAS VALVE The gas valves used on all BTR water heaters are 24 volt AC combination step opening gas valves. They incorporate the pilot valve, main valve, and gas pressure regulators into one body. The inlet view of the valve features a filter screen and the top knob. The top knob is a manual on/off gas control for both the pilot and main gas valves. When the top knob is placed on the black mark, gas is supplied only to the pilot valve. On the top view, w
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BTR TANK TYPE HEATERS SERVICE HANDBOOK VENTING Atmospheric Multiple Heaters Chimney A minimum of ¼” rise per foot of horizontal vent is required. All BTR water heaters are classified by ANSI as category I (non-condensing, negative pressure venting) appliances. They are approved for type B vent. For larger applications, BTR water heaters can be common vented together either in a tapered manifold or constant size manifold. (Follow National Fuel Gas Code requirements for sizing and installation.) B
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BTR TANK TYPE HEATERS SERVICE HANDBOOK DRAFT INDUCER Draft inducers can be used with BTR water heaters to mechanically aid a lazy chimney in vertical vent applications. They are not designed to allow “through-the-wall” vent installations. (See Power Venter) SINGLE UNIT INSTALLATION When mechanically venting, the following items are required: Qty Description Part No. 1 Draft Inducer (up to 300,000Btuh) 90909 1 Draft Inducer (up to 305,000 thru 500,000 Btuh) 90910 1 Draft Prover Switch 95220 1 Rel
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BTR TANK TYPE HEATERS SERVICE HANDBOOK POWER VENT KITS FOR SIDEWALL VENTING Female plug to Damper 40’, Power Venter cablewith“Y” connect Male plug to Cable Water Heater Models Part Number BTR-120-200 193933-0 BTR-250-500 193933-1 BTR water heaters can be used with power vent kits for sidewall venting. A.O. Smith offers power vent kits for use on installations with a maximum of 100 equivalent feet of vent piping. The power vent kits also use type B vent materials. When power venting, specific ext
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BTR TANK TYPE HEATERS SERVICE HANDBOOK BTR SEQUENCE OF OPERATION 9. Flue damper closes 2. Flue damper opens 1. Thermostat calls for heat 7. Thermostat satisfies 4. Pilot gas opens, Pilot sparks and flame proves 3. Intermittent Ignition Control 6. Main burner ignites 5. Main gas valve opens 8. Main and pilot burners "OFF" SEQUENCE OF OPERATION To understand BTR tank type water heaters, an examination of their sequence of operation is necessary. When the thermostat calls for heat, the relay in the
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BTR TANK TYPE HEATERS SERVICE HANDBOOK BTR ELECTRICAL SEQUENCE 100 – 109 Series A.O. Smith Water Products Service Handbook 17 Irving, Texas ©2000 Training Department
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BTR TANK TYPE HEATERS SERVICE HANDBOOK BTR ELECTRICAL SEQUENCE OF OPERATION 120 Vac to Junction Box On / OFF Switch "ON" 2 4V Transform er Tank Tem perature Tank Tem perature Satisfied High Lim it Closed High Lim it (ECO) Closed Therm ostat Closed Motor Closes Series 110 and 111 Damper Effikal M otor Relay Interrupts Power to Motor Motor Opens Dam per Dam per Spring Opens Dam per Blade Cam On Dam per Blade Closes Proving End S witch IID Module (24V) Receives Voltage Module (PV) Tem inal Module
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BTR TANK TYPE HEATERS SERVICE HANDBOOK TROUBLESHOOTING BTR WATER HEATERS To troubleshoot a BTR water heater check that: • 120 VAC is supplied to the heater • the tank is full of water gas is supplied to the unit • STEP 1 TEST THE TRANSFORMER - Using a multimeter, test for 24 VAC STEP 1 - TO TEST THE TRANSFORMER between the secondary transformer terminals. IF THEN The meter does not read 24 VAC: Check that the 120 VAC is supplied • from the On/Off Switch – if not, replace switch. Check that the
