Installation and Operation Instructions Document 1211E Installation and Operation Instructions for MIGHTY THERM 2 ® Hydronic Boiler Model MT2H Volume Water Heater Model MT2V Sizes 500–2000 MBTU/h FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician, qualified in hot water boiler installation and maintenance. Improper installation and/or operation could create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death.
LAARS Heating Systems Page 2 TABLE OF CONTENTS SECTION 1. General Information 1.1 1.2 1.3 1.4 1.5 1.6 Introduction.......................................................... 3 Model Identification.............................................. 3 Warranty.............................................................. 4 Dimensions.......................................................... 4 Locating the Appliance........................................
Mighty Therm2 Page 3 SECTION 1. General Information USING THIS MANUAL – Because Mighty Therm2 Boilers and Water Heaters are identical appliances, with the exception of materials of manufacture, labels and ultimate use application, this manual provides information for the proper installation, operation and maintenance of all products. Where differences exist between the application of the appliances and their operation, the sections pertinent to only one appliance or the other will be so identified.
LAARS Heating Systems Page 4 9 Fuel N = Natural Gas P = Propane 10 Altitude A = 0–10,000 feet 11 Location C = Indoor and Outdoor 12 Firing Mode K = Two-stage 13 Revision 1 = First version of design 14 Heat Exchanger B = Glass-lined cast iron / copper / bronze trim (std. on water heaters) C = Glass-lined cast iron / copper (std.
Mighty Therm2 Page 5 Unit Size A B C D E Air Conn. W Vent Conn.
LAARS Heating Systems Page 6 Size A B C D E F 500 33¾ 86 16¾ 43 6½ 17 10 25 750 45¾ 116 22¾ 58 6½ 17 1000 57¾ 147 28¾ 73 6½ 1250 68¼ 173 34¼ 1500 78¾ 200 1750 89¼ 227 2000 99¾ 253 8 Air Conn. W Vent Conn.
Mighty Therm2 in the appliance has/have sufficient power to pull air and vent properly when the following guidelines for horizontal air and vent are followed (see Table 2). NOTE: The vent collar size is larger than the size of the vent pipe that can be used. Vent collar size and horizontal pipe diameters can be found in Table 2. The larger vent collar size is to accommodate Category I (vertical) vent systems.
LAARS Heating Systems Page 8 and combustion air ducting attached to the top. In addition to air needed for combustion, air shall also be supplied for ventilation, including all air required for comfort and proper working conditions for personnel. The Mighty Therm2 loses less than 1 percent of its input rating to the room, but other heat sources may be present. 2.2 Venting 2.2.1 Vent Categories Depending upon desired Mighty Therm2 venting, it may be considered a Category I or a Category III appliance.
Mighty Therm2 Page 9 2.2.4 Category III Vent When the Mighty Therm2 is vented with horizontal discharge, it must be installed per this installation manual and the venting system manufacturer’s installation instructions. The vent system must be sealed stainless steel (see Table 5). Route the vent pipe to the heater as directly as possible. Seal all joints and provide adequate hangers as required in the venting system manufacturer’s Installation Instructions.
Page 10 U.S. Installations (see note 1) A= Clearance above grade, veranda, porch, 12 inches (30 cm) deck, or balcony B= Clearance to window or door that may be 4 feet (1.
Mighty Therm2 at which it penetrates the roof. It must extend at least 2 feet (0.6m) higher than any portion of a building within a horizontal distance of 10 feet (3.0m), and high enough above the roof line to prevent blockage from snow. When the combustion air is taken from the roof, the combustion air must terminate at least 12" (30cm) below the vent terminal (see Figure 3). Seek local municipalities and their codes for appropriate installation techniques.
LAARS Heating Systems Page 12 4. 5. 6. 7. and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliance not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.
Mighty Therm2 Mighty Therm2’s gas train allows the user to pipe the gas from either the right side or the left side of the unit. As shipped, the right side of the gas train is capped off, and there is a manual valve on the left side. If desired, the manual valve on the left side of the gas train may be moved to the right side, and the cap on the right side may be moved to the left. Review the following instructions before proceeding with the installation. 1.
Page 14 through the system resulting from the piping sliding in the hangers. It is recommended that padding be used when rigid hangers are installed. Maintain 1" clearance to combustibles for hot water pipes. Pipe the discharge of the relief valve (full size) to a drain or in a manner to prevent injury in the event of pressure relief. Install an air purger, an air vent, a diaphragm-type expansion tank, and a hydronic flow check in the system supply loop. Minimum fill pressure must be 12psig (82.7kPa).
Mighty Therm2 occurs. Do not reduce line size or install any valves in this line. The line must be installed to allow complete drainage of both the valve and the line. Suggested piping diagrams are shown in Figures 11 through 14. These diagrams are meant only as a guide. Components required by local codes must be properly installed. The minimum inlet water temperature for the Mighty Therm2 is 120°F (49°C) to avoid condensing on the copper coils. 4B.
Page 16 Figure 6. Hydronic Piping — Multiple Boilers, Primary Secondary System. Figure 7. Hydronic Piping — Multiple Boilers, Low Temperature System.
Mighty Therm2 Figure 8. Hydronic Piping — One Boiler, Multi-Temperature System. Figure 9. Hydronic Piping - Primary-Secondary, Reverse-Return.
Page 18 Figure 10. Hydronic Piping - Primary-Secondary, Reverse-Return, Low Temperature. Figure 11. Water Heater Piping — One Heater, One Tank.
Mighty Therm2 Figure 12. Water Heater Piping — Multiple Heaters, One Tank. Figure 13. Water Heater Piping — One Heater, Multiple Tanks.
LAARS Heating Systems Page 20 Figure 14. Water Heater Piping — Multiple Heaters, Multiple Tanks. Unit gpm ft Temp Rise °F Size S N H S N H S N 500 45 68 90 1.8 2.3 3.5 19 750 45 68 90 2.1 3.0 6.0 28 1000 45 68 90 2.3 3.6 6.1 1250 68 68 90 3.8 3.8 6.3 1500 68 68 90 3.9 3.9 1750 68 68 90 4.0 4.0 2000 112 112 112 10.0 10.0 NOTES: lpm m Temp Rise °C H S N H S N H S N H 13 9 170 257 341 0.5 0.7 1.
Mighty Therm2 Page 21 Single pole switches, including those of safety controls and protective devices must not be wired in a grounded line. All electrical connections are made in the field wiring terminal strip, which is located at the right side of the appliance. NOTE: All internal electrical components have been prewired. No attempt should be made to connect electrical wires to any other location except the wiring box. 5.
LAARS Heating Systems Page 22 TB1-1 L1 MAIN POWER SWITCH DPDT N1 120 VAC JUMPER HSI #1 IGN BD #1 35 67 L1 IGN BD #1 35 67 S1 IGN BD #2 35 67 L1 IGN BD #2 35 67 S1 IGN BD #1 35 67 S2 IGN BD #1 35 67 L2 IGN BD #2 35 67 S2 IGN BD #2 35 67 L2 HSI #2 BLOWER 1 HIGH K1 K1 LOW BLOWER 2 HIGH K2 K2 LOW PUMP K3 120 VAC 2 1 TO PUMP P1 P2 24 VAC 1 IGN BD #1 35 67 24V IGN BD #1 35 67 F1 IGN BD #1 35 67 F2 35 67 F1 IGN BD #2 35 67 F2 IGN BD #2 LOW GAS 35 67 GND 35 67 IGN 24V BD #2 35 67 G
Mighty Therm2 Figure 19. Mighty Therm2 (500–750) Connection Diagram.
Page 24 Figure 20. Mighty Therm2 (1000) Connection Diagram.
Figure 21. Mighty Therm2 (1250–2000) Connection Diagram.
Page 26 units have an internal (dry) contact rated for 20Amps. A field-supplied pump can be connected directly to this contact if it does not draw more than 20 Amps. If more current is required, a separate pump contactor must be installed. To utilize this internal pump contact, supply 120 volt single-phase power to the terminal marked “120V (L2)” and supply the pump using the terminal marked “L2 LOAD (EXT. PUMP)”.
Mighty Therm2 6.2 Filling the System 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Ensure the system is fully connected. Close all bleeding devices and open make-up water valve. Allow system to fill slowly. If make-up water pump is employed, adjust pressure switch on pumping system to provide a minimum of 12 psi (81.8 kPa) at the highest point in the heating loop. If a water pressure regulator is provided on the make-up water line, adjust the pressure regulator to provide at least 12 psi (81.
LAARS Heating Systems Page 28 water and the manual reset high limit senses outlet water, the high limit should be set 40-50°F higher than the controller, to avoid nuisance lockout of the manual reset high limit. 7. 6.4 External Boiler Operations If controlling the stages of the MT2 from an external source (multiple boiler control, BAS, etc) the "Local/Remote" selector switch above the terminal strip must be placed in the "Remote" position.
Mighty Therm2 with two blowers should be adjusted so that the air shutters below each blower are open the same amount. Once the CO2 or O2 has been set, the manifold pressure may be adjusted. Remove the 1/8 NPT plug from the lower side of the gas valve that is to be set and install a fitting, hose and manometer. Start the appliance and observe the manifold pressure. Manifold pressure must be adjusted to 3.0 in. W.C. (0.75 kPa) (for high altitude only, standard operating pressure is 2.5 in. W.C. (0.62 kPa)).
Page 30 every year. a. Ignition controls b. Ignitors c. Water temperature control d. Automatic gas valve e. Pressure switches f. Blowers 7.2.1 Burners Close main manual gas valve before proceeding. Checking the burners for debris - Remove the ignitor inspection panels(s) and ignitor(s) and inspect the burners through the ignitor hole(s) using a flashlight to illuminate. If there is any indication of debris on the burners that are visible, all the burners will need to be inspected more thoroughly.
Mighty Therm2 power and gas supply to the unit. Remove the front panel. Disconnect the blower's wire harness. Remove the screws at the blower flange, and pull the blower out. Replace blower in reverse order, ensuring that all joints are made correctly. After replacement, ensure that the unit operates properly, by following the set-up procedure in this manual. 7.2.10 Flow Switch The Mighty Therm2 uses a paddle-type flow switch to ensure that the unit has water flow before ignition is allowed. 7.2.
Page 32 3. be suspected if there is a strong flue gas odor. The odor may result from an improper gas/air ratio (high or low O2 or CO2). Mighty Therm2 appliances operate best with 45% excess air (8% CO2 on natural gas, 9.2% CO2 on LP). Check the CO2 of the appliance and adjust if necessary. Ignitor failure: If the boiler goes through a normal start cycle but combustion does not occur, ignitor failure should be suspected. Check the ignitor by unplugging the ignitor plug and measuring the ignitor resistance.
Size 750 Size 1000 Size 1250 Size 1500 Size 1750 Size 2000 (1) 5F3015 5F3016 5F3304 (2) (1) 5F3015 5F3016 5F3304 (2) (2) 5F3015 5F3016 10F3304 (1) (2) 5F3015 5F3016 20F3304 (2) (2) 5F3015 5F3016 20F3304 (2) (2) 5F3015 5F3016 20F3304 (2) (2) 5F3015 5F3016 20F3304 (2) 5F3320 7F3320 10F3320 12F3320 15F3320 17F3320 20F3320 5F3420 5F3420 5F3420 5F3420 5F3420 5F3420 5F3420 5F3421 5F3421 5F3421 5F3421 5F3421 5F3421 5F3421 5F3520 5F3520 5F3520 5F3520 5F3520 5F3520 5F3520 5F3521 5F352
Size 500 Size 750 Size 1000 Size 1250 Size 1500 Size 1750 Size 2000 Assembly, Copper Tube, Heat Exchanger 5C4000 7C4000 10C4000 12C4000 15C4000 17C4000 20C4000 Assembly, Cupro-Nickel, Heat Exchanger 5C4020 7C4020 10C4020 12C4020 15C4020 17C4020 20C4020 33 Tile, Side (Left and Right) T2015600 T2015600 T2015600 T2015600 T2015600 T2015600 T2015600 (2) (2) (2) (2) (2) (2) (2) 34 Tile, Front T2017300 35 Tile, Front, Left Side T2016200 T2016800 T2016800 T2016800 T2016800 T2016800 T2016800 36 Tile,
Size 500 Size 750 Size 1000 Size 1250 (24) L2012400 (24) (3) L2013000 (21) L2012400 (21) S2012700 (3) L2013000 (18) L2012400 (18) S2012700 (3) 2400-286 (2) (3) 2400-286 (2) (2) 2400-286 (4) L2013000 (3) L2012500 (2) L2012500 (3) (2) L2012500 (1) L2012200 (1) L2012200 S2012500 (2) L2012200 (2) L2012700 (2) L2012700 (2) (4) L2012700 (1) L2012600 L2012600 S2012500 L2012600 L2012900 Size 2000 (1) Size 1750 L2012900 Size 1500 58 59 60 62 Heat Exchanger Compo
Baffle, Water Deflector, Inlet Well, Immersion, Temperature Control Cover, Return, Glass-Lined Cast Iron Cover, Return, Bronze Pump Housing, Glass-Lined Cast Iron Baffle, Diffuser, Pump Housing Inlet 10338300 E2058300 10364300 10364301 S2056900 10338400 Size 500 10338300 E2058300 10364300 10364301 S2056900 10338400 Size 750 10338300 E2058300 10364300 10364301 S2056900 10338400 Size 1000 10338300 E2058300 10364300 10364301 S2056900 10338400 Size 1250 10338300 E2058300 10364300 10364301 S2056900 1033
Mighty Therm2 Figure 23. Sheet Metal Components.
Page 38 Figure 24.
Mighty Therm2 Page 39 Mighty Therm2 Water Heater Mighty Therm2 Hydronic Boiler Size Pump p/n 500 A2001700 Size Pump p/n Soft Water Normal Water Hard Water 500 A2001700 A2001700 A2001900 750 A2001700 750 A2001700 A2001700 A2001900 1000 A2001800 1000 A2001700 A2001800 A2001900 1250 A2001800 1250 A2001700 A2001800 A2001900 1500 A2001900 1500 A2001700 A2001900 A2001900 1750 A2001900 1750 A2001900 A2001900 A2001900 2000 A2109700 2000 A2109700 A2109700 A2109700
LAARS Heating Systems Page 40 H2329100E Figure 26. Electrical Components. Laars Heating Systems Company reserves the right to change specifications, components, features, or to discontinue products without notice. 800.900.9276 • Fax 800.559.1583 (Customer Service, Service Advisors) 20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355 (Applications Engineering) 1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax 905.366.0130 www.Laars.com Litho in U.S.A.
