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LAARS Heating Systems

Page 26

 

SECTION 6.

Operating Instructions

6.1  Filling the Boiler System

1.  Ensure the system is fully connected. Close all 

bleeding devices and open make-up water valve. 

Allow system to fill slowly.

2.  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.

3.  If a water pressure regulator is provided on the 

make-up water line, adjust the pressure regulator 

to provide at least 12 psi (81.8 kPa) at the highest 

point in the heating loop.

4.  Open bleeding devices on all radiation units 

at the high points in the piping throughout 

the system, unless automatic air bleeders are 

provided at such points.

5.  Run system circulating pump for a minimum of 

30 minutes with the boiler shut off.

6.  Open all strainers in the circulating system, 

check flow switch operation, and check for 

debris. If debris is present, clean out to ensure 

proper circulation.

7.  Recheck all air bleeders as described in Step 4.

8.  Check liquid level in expansion tank. With the 

system full of water and under normal operating 

pressure, the level of water in the expansion tank 

should not exceed ¼ of the total, with the balance 

filled with air.

9.  Start up boiler according to the procedure in this 

manual. Operate the entire system, including the 

pump, boiler, and radiation units for one (1) hour.

10.  Recheck the water level in the expansion tank. If 

the water level exceeds ¼ of the volume of the 

expansion tank, open the tank drain, and drain to 

that level.

11.  Shut down the entire system and vent all 

radiation units and high points in the system 

piping, as described in Step 4.

12.  Close make-up water valve and check strainer in 

pressure reducing valve for sediment or debris 

from the make-up water line. Reopen make-up 

water valve.

13.  Check gauge for correct water pressure and also 

check water level in the system. If the height 

indicated above the boiler insures that water is at 

the highest point in the circulating loop, then the 

system is ready for operation.

14.  Refer to local codes and the make-up water 

valve manufacturer’s instructions as to whether 

the make-up water valve should be left open or 

closed.

15.  After placing the unit in operation, the ignition 

system safety shutoff device must be tested. 

First, shut off the manual gas valve, and call 

the unit for heat. After the pre-purge and ignitor 

heat-up time, the main gas terminals will be 

energized, attempting to light, for seven (7) 

seconds, and then will de-energize. The unit will 

attempt to light two more times, and then will go 

into lockout mode. Second, turn the power off 

and then on again, open the manual gas valve 

and allow the unit to light. While the unit is 

operating, close the manual gas valve and ensure 

that power to the main gas valve has been cut.

16.  Within three (3) days of start-up, recheck all air 

bleeders and the expansion tank as described in 

Steps 4 and 8 above.

Important: The installer is responsible for identifying 

to the owner/operator the location of all emergency 

shutoff devices.

   WARNING

Do not use this appliance if any part has been under 

water. Immediately call a qualified service technician 

to inspect the appliance and to replace any part of 

the control system and any gas control that may have 

been under water.

 AVERTISSEMENT

N’utilisez pas cet appareil si l’une de ses pièces est 

passée sous l’eau. Appelez tout de suite un technicien 

en entretien et en réparation pour inspection de 

l’appareil et remplacement des pièces du système de 

commande, et des pièces de commande du circuit 

gaz, qui sont passées sous l’eau. 

6.2  Operating Temperature Control

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Control Access Panel

 

Note: The Dip switch panel and LED panel 

can be found under the Control Access Panel after 

removing the bolts. 

 

Summary of Dip Switch Settings:

#1 Two Stage (Off) / Single Stage (On) 

#2  Setpoint (Off) / Outdoor Reset (On) (Note: 

Outdoor Reset is required for residential 

operation)

#3 WWSD Inactive (Off) / Active 70°F (On) 

#4 Boiler Maximum 210°F (Off) / 190°F (On) 

#5  Pump Post Purge Inactive (Off) / Active 3 

min. (On) 

 

Summary of Contents for Mighty Therm 2 MT2H

Page 1: ...r installation and or operation will void the warranty For indoor installations as an additional measure of safety Laars strongly recommends installation of suitable Carbon Monoxide detectors in the v...

Page 2: ...16 SECTION 4B Water Connections Water Heater 4B 1 Water System Piping Water Heater 20 4B 2 Hot Water Supply Piping Water Heater 20 4B 3 Water Flow Requirements Water Heater 20 4B 4 Combined Water pota...

Page 3: ...da the Canadian Electrical Code Part 1 CSA STD C22 1 and all applicable local codes as required by the AHJ This appliance must be electrically grounded in accordance with the applicable codes and stan...

Page 4: ...e installer Shipping costs are not included in the warranty coverage Some accessory items are shipped in separate packages Verify receipt of all packages listed on the packing slip Inspect everything...

Page 5: ...ions may be on top or back of the Mighty Therm2 and are field convertible Model A Combustion Air Connection B Vent Connection C Horizontal Cat III Vent Pipe Size in cm in cm in cm in cm 200 20 5 52 4...

Page 6: ...may be on top or back of the Mighty Therm2 and are field convertible Model A Combustion Air Connection B Vent Connection C Horizontal Cat III Vent Pipe Size in cm in cm in cm in cm 200 20 5 52 4 10 5...

Page 7: ...Material Recommended Service Access Clearance inches cm inches cm Left Side 1 2 5 24 61 Right Side 1 2 5 24 61 Top 1 2 5 12 30 Back 1 2 5 12 30 Front 1 2 5 36 91 Vertical Category 1 Vent 6 15 2 Horiz...

Page 8: ...e outdoors or when communicating to the outdoors through vertical ducts each opening shall have a minimum free area of 1 square inch per 4000 Btu hr 5 5 square cm kW of total input rating of all equip...

Page 9: ...ting it may be considered a Category I or a Category III appliance In general a vertical vent system will be a Category I system However in rare instances a Mighty Therm2 s vertical vent system may be...

Page 10: ...perating instructions on all appliances to be common vented for instructions warnings restrictions and safety requirements If safe operation of all appliances connected to a common vent cannot be assu...

Page 11: ...to non mechanical air supply Direct Vent Only 12 inches 30 cm inlet to building or the combustion air inlet Other Than Direct Vent 4 feet 1 2 m below or 36 inches 91 cm to any other appliance to side...

Page 12: ...addition the installing plumber or gasfitter shall observe that a battery operated or hard wired carbon monoxide detector with an alarm is installed on each additional level of the dwelling building o...

Page 13: ...combustion air terminal so that it cannot be blocked by snow The National Fuel Gas Code requires that it be at least 12 inches 30 cm above grade but the installer may determine it should be higher dep...

Page 14: ...tes et les fen tres du b timent et toutes les portes entre l espace o les appareils toujours raccord s au syst me d vacuation sont install s et les autres espaces du b timent Mettre en marche les s ch...

Page 15: ...sediment trap must be provided upstream of the gas controls 7 All threaded joints should be coated with piping compound resistant to action of liquefied petroleum gas 8 The appliance and its individu...

Page 16: ...coils located in air handling appliances where they may be exposed to refrigerated air circulation must be equipped with flow control valves or other automatic means to prevent gravity circulation of...

Page 17: ...minute H L head loss ft head loss in feet m head loss in meters Maximum temperature rise is 35 F 19 C as shown Head loss is for boiler s heat exchanger only N R not recommended Table 8 Water Flow Requ...

Page 18: ...LAARS Heating Systems Page 18 Figure 5 Hydronic Piping Multiple Boilers Low Temperature System Figure 6 Hydronic Piping One Boiler Multi Temperature System...

Page 19: ...Mighty Therm2 200 300 400 Page 19 Figure 7 Hydronic Piping Primary Secondary Reverse Return Figure 8 Hydronic Piping Primary Secondary Reverse Return Low Temperature...

Page 20: ...Gas Shutoff Devices for Hot Water Supply Systems ANSI Z21 22 CSA 4 4 of suitable discharge capacity must be installed in the separate storage tank system If the Mighty Therm2 water heater is installed...

Page 21: ...or the water is not able to circulate there is a risk of freezing in the heater or in the pipes in the system When water freezes it expands This can result in bursting of pipes in the system or damag...

Page 22: ...SOFT N NORMAL H HARD 1 THROUGH 7 5 7 6 THROUGH 17 OVER 17 2 3 4 Figure 10 Water Heater Piping Multiple Heaters One Tank SUPPLY RECIRC CWMU CAUTION THIS DRAWING SHOWS SUGGESTED PIPING CONFIGURATION AN...

Page 23: ...ANSION TANK 3 WAY VALVE VALVE PRESSURE REDUCING VALVE PUMP PRV TPRV Figure 12 Water Heater Piping Multiple Heaters Multiple Tanks CAUTION THIS DRAWING SHOWS SUGGESTED PIPING CONFIGURATION AND VALVING...

Page 24: ...BK BL Y R BL W Y BLK BL R W W Y BLK GY V BK GY BK GY BK V W V W BR R BR BK BR BLK BR BLK R BK R BK BR BK BR R Y R G G G G BK W W W POWER BK BK BK BK BK BK BK BK BL R BL R BK STAGE 2 GAS VALVE STAGE 1...

Page 25: ...ral wires are provided for connections inside the boiler jacket Ground wire can be connected to the grounding screw in the box Wiring diagrams are shown in Figures 15 16 5 2 Field Wiring Field Install...

Page 26: ...r insures that water is at the highest point in the circulating loop then the system is ready for operation 14 Refer to local codes and the make up water valve manufacturer s instructions as to whethe...

Page 27: ...DE MUST NOT BE USED UNLESS AT LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE An external energy management system is installed that reduces the boiler water temperature as the heating load decreases Th...

Page 28: ...ust plenum This switch opens if the pressure is excessive as an indicator of a blocked vent When these two pressure switches are closed voltage is sent to the PSW terminal on the ignition control whic...

Page 29: ...n the Burner Safety Shutoff Device must be tested To test a Close gas shutoff valve with burner operating b The flame will go out and blower will continue to run for the post purge cycle Three attempt...

Page 30: ...when servicing controls Wiring errors can cause improper and dangerous operation Verify proper operation after servicing Attention Lors d entretien ou de r paration des commandes tiquetez tous les c...

Page 31: ...le switch with a remote bulb type sensor Switches for water heaters and low temperature boiler models are set at 200 F Switches for standard boilers are set at 240 F The control is located behind the...

Page 32: ...with sufficient air for complete combustion and black carbon sooting is seldom experienced If sooting is suspected view ports for inspection of the heat exchanger are provided on the side of the boil...

Page 33: ...cling Boiler Boiler short cycling is caused when the load on the boiler system swings rapidly causing frequent cycling between call for heat and satisfied conditions This condition is greatly reduced...

Page 34: ...ent Flue 2C2300 2C2300 2C2300 18 Assembly Air Shutter Blower 2C5000 2C5000 2C5000 19 Assembly Filter Housing 2C3800 2C3800 2C3800 20 Media Filter R2073200 R2073200 R2073200 21 Clip Retaining Filter Me...

Page 35: ...r Copper R2C4100 R3C4100 R4C4100 Assembly Tube Heat Exchanger Copper Nickel R2C4120 R3C4120 R4C4120 61 Header Inlet Outlet 2F4122 2F4122 2F4122 62 Header Return 2C4103 2C4103 2C4103 63 Chamber Header...

Page 36: ...7004 2C7004 2C7004 93 Switch Pressure Diaphragm SPST E0255500 E0255500 E0255500 94 Switch Pressure Diaphragm SPDT RE0240900 RE0240900 RE0240900 95 Switch Limit High Temperature Hydronic E2304800 E2304...

Page 37: ...Mighty Therm2 200 300 400 Page 37 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 22 23 24 25 26 27 28 29 30 31 31 31 31 31 32 20 21 19 Figure 20 Combustion Chamber Components...

Page 38: ...LAARS Heating Systems Page 38 Figure 21 Jacket Components 40 41 42 48 51 43 44 45 46 47 49 50 52 53 54 54 55...

Page 39: ...Mighty Therm2 200 300 400 Page 39 60 62 63 63 64 64 73 65 66 67 70 68 72 69B 69A 61 71 Figure 22 Heat Exchanger Components...

Page 40: ...LAARS Heating Systems Page 40 80 81 85 84 84 86 87 ON OFF 80 82 83 85 86 86 2 STAGE Figure 23 Gas Train Components...

Page 41: ...Mighty Therm2 200 300 400 Page 41 102 104 106 97 Figure 24 Control Panel Components...

Page 42: ...hester NH 03867 603 335 6300 Fax 603 335 3355 1869 Sismet Road Mississauga Ontario Canada L4W 1W8 905 238 0100 Fax 905 366 0130 www Laars com Litho in U S A Laars Heating Systems 1209 Document 1231B D...

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