Laarsen Associates VW manual

FOR YOUR SAFETY : This product must be inst alled and serviced by a professional service technician, qualified in hot water heater 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. Improper installation and/or operation wi[...]

LAARS HEATING SYSTEMS Page 2 SECTION 1. General Information 1A. Introduction ................................................... 3 1B. Heater Identification ..................................... 3 1C. Flow Requirements ...................................... 4 1D. Water Chemistry ........................................... 4 SECTION 2. Installation [...]

Mighty Therm Volume Water Heater Page 3 SECTION 1. General Information 1A. Introduction This manual provides information for the installation and operation of Laars volume water heaters. It is strongly recommended that all application and installation procedures be reviewed completely before proceeding with the installation. Consult the Laars facto[...]

LAARS HEATING SYSTEMS Page 4 1C. Flow Requirements For proper operation, all low volume hot water heaters must have continuous flow through the heat exchanger when firing. The system pump must be capable of developing sufficient pressure to overcome the resistance of the heater plus the entire circulating system at the designed flow rate. 1D. Water[...]

Mighty Therm Volume Water Heater Page 5 Figure 2. Typical Heater Installation with Base for Combustible Floors, Example A. Figure 3. Typical Heater Installation with Base for Combustible Floors, Example B. Figure 4. Typical Heater Installation with Base for Combustible Floors, Example C. Figure 5. Installation on Concrete Blocks or Tile. * When the[...]

LAARS HEATING SYSTEMS Page 6 2B-1. Combustion Air Supply 1. The heater location must provide sufficient air supply for proper combustion and ventilation of the surrounding area as outlined in the latest edition of ANSI standard Z223.1, and any local codes that may be applicable. Inadequate combustion air supply may result in incomplete combustion, [...]

Mighty Therm Volume Water Heater Page 7 maintain clearances and prevent physical damage and separation of joints. 4. Avoid ending heater vents near air conditioning or air supply fans. The fans can pick up exhaust flue products from the heater and return them inside the building, creating a possible health hazard. A minimum of 4 feet horizontal dis[...]

LAARS HEATING SYSTEMS Page 8 4. The boiler and its individual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of 1/2 psig. The boiler must be isolated from the gas supply piping system by closing its individual manual gas shutoff valve during any pressure te[...]

Mighty Therm Volume Water Heater Page 9 Special attention must be given to relief valve settings in installations where the heater is located on the ground floor of a tall building. The static pressure of the system is elevated and could cause the relief valve to leak. Where no special setting of the relief valve is ordered, the factory will furnis[...]

LAARS HEATING SYSTEMS Page 10 2H. Pump Performance and Installation 1. The factory provided pump on PW heaters and the recommended field provided pump for model VW heaters are sized to provide proper circulation through the heater and heater-to- tank circulation loop (see Figures 11 and 12). If the heater-to-tank circulating loop does not contain m[...]

Mighty Therm Volume Water Heater Page 11 Figure 11. Hot Water Supply System (Model VW & PW). With V ertical T ank With Horizontal T ank NOTES: Heavy line indicates Heater to Tank Circulating Loop.[...]

LAARS HEATING SYSTEMS Page 12 CAUTION: 1. This piping arrangement is required on split systems to provide constant hot water temperatures. 2. Pipe size and length must conform to the recommendations for each heater model. 3. A loop circulator is required to maintain forced circulation in the building hot water piping system. Figure 13. Split System[...]

Mighty Therm Volume Water Heater Page 13 Figure 15. Single Installation Piping Diagram, Model IW. Figure 14. Dual Installation Piping Diagram, Model IW. NOTES: 1. All water connections 2" N.P.T. models. 2. Drain valve per ASME requirements. 3. A loop circulator is required to maintain forced circulation in the building hot water piping system.[...]

LAARS HEATING SYSTEMS Page 14 Figure 16. Two-Temperature Hot Water Supply System (Model VW or PW). With V ertical T ank With Horizontal T ank Legend B - Check Valve in Hot Water Supply to Tempering Valve C - Check Valve in Return Line from Building Loop D - Tempering Valve E - Venturi (Suction) Tee H - Throttling Valves in Building Loop Returns I -[...]

Mighty Therm Volume Water Heater Page 15 Figure 17. Two-Temperature Hot Water Supply System with Vertical Tank for Models VW and PW Water Heaters. Legend B - Check Valve C - Check Valve D - Tempering Valve H - Throttling Valves in Building Loop Returns J - Circulating Pump for Return Loop K - Service Valves to Isolate Heater and Pump for Service[...]

LAARS HEATING SYSTEMS Page 16 2 I . Water Pressure It is very important that water pressure in the system be maintained above 30 psi. If the system pressure should drop below this, the vapor pressure of water in the suction side of the pump can cause hammer and cavitation in the pump and damage the heater through lack of water circulation. If for a[...]

Mighty Therm Volume Water Heater Page 17 proven to be lit. Whenever the pilot flame is interrupted, the main gas valve closes within 0.8 seconds. b. Electronically Supervised Standing Pilot System (System #16): When pilot flame fails, the ignition control module responds in less than 0.8 seconds and provides 100% safety shutdown. 2. Operating Contr[...]

LAARS HEATING SYSTEMS Page 18 gas supply, the automatic safety shutoff devices must be checked. 1. Before beginning the tests, make sure the main manual gas valve, and any other heater firing valves are in the “OFF” position. 2. Make sure the heater’s power switch is in the “ON” position. After placing the manual pilot gas valve in the op[...]

Mighty Therm Volume Water Heater Page 19 depressed for one minute then release. Once the pilot is lit, the power is supplied through the aquastat to the main gas valve. 2. To set the temperature and high-limit controls: When using a tank aquastat: Set the tank aquastat to the desired tank temperature. Set the heater temperature control 20°F higher[...]

LAARS HEATING SYSTEMS Page 20 Lower the front of the burner (to avoid damaging pilot shield) then remove the burner tray. Caution Black carbon or green soot on a dirty heat exchanger can, under certain conditions, be ignited by a random spark or open flame. To prevent this unlikely occurrence, dampen the soot deposits with wet brush or fine water s[...]

Mighty Therm Volume Water Heater Page 21 II. HEATER IS POUNDING, KNOCKING OR EMITTING STEAM FROM RELIEF VALVES. Possible Cause What To Do A. Low or no water flow. A. This condition is usually caused by lack of adequate water flow through heater. Check the following: 1. Is the heater wired into the pump circuit so that the heater cannot fire unless [...]

LAARS HEATING SYSTEMS Page 22 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 1 T op Panel Assembly 10535701 10535702 10535703 10535704 10535705 10535706 10535707 10535708 10535709 2 S pacer , Flue Collector — — 10540800 10540800 10540800 10540800 10540800 10540800 3 End Pan[...]

Mighty Therm Volume Water Heater Page 23 Figure 22. Parts Identification. NOTE: T emperature Control Wells - Inlet/Outlet Header 1. Firing Mode L, K, & C - 2 Dry Wells 2. Firing Mode H A. Natural Gas Boilers & Heaters 500 thru 850 - 2 Dry Wells 1010 thru 1430 - 3 Dry Wells 1670 thru 1825 - 4 Dry Wells B. Propane Gas Boilers & Heaters 50[...]

LAARS HEATING SYSTEMS Page 24 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 2 1 T ile, Heat Shield/Spcr , Frt. & Rr . 10560100 — — — — —— — — —— — — —— — — (2) 22 T ile, Heat Shield/Sp acer , Front —— 10547901 10547902 —— —— 1054[...]

Mighty Therm Volume Water Heater Page 25 Figure 23. Tile Assemblies.[...]

LAARS HEATING SYSTEMS Page 26 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 4 3 Ignition Control, Electronic E0100900 E0100900 E0100900 E0100900 E0100900 E0100900 E0100900 E0100900 E0100900 4 4 T ransformer , 1 1 5V/24V E0086100 E0086100 E0086100 E0086100 E0086100 E0086100 E00[...]

Mighty Therm Volume Water Heater Page 27 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 715 85 0 1010 1200 1430 1670 1825 6 4 Safety Gas V alve, On-Off, T wo St age (Nat) V0046600 V0046600 V004600 V004600 V0046700 V0046700 V0046700 V0046700 V0046800 65 Safety Gas V alve, On-Off, T wo St age (Pro) V0046600 V00466[...]

LAARS HEATING SYSTEMS Page 28 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 8 9 Plug, 3/4, Sq. Hd. P0027000 P0027000 P0027000 P0027000 P0027000 P0027000 P0027000 P0027000 P0027000 9 0 Pipe Extension 1/2" Female Pipe Extension 1/2" Male P0072300 P0072300 P0072300 P007[...]

Mighty Therm Volume Water Heater Page 29 Figure 21. Outdoor Parts.[...]

LAARS HEATING SYSTEMS Page 30 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 1 T op Panel Assembly 10660701 10660702 10660703 10660704 10660705 10660706 10660707 10660708 10660709 2 Rear Windshield 10658101 10658102 10658103 10658104 10658105 10658106 10658107 10658108 10658109[...]

Mighty Therm Volume Water Heater Page 31 Key Description Model Model Model Model Model Model Model Model Model N o 50 0 6 00 71 5 8 50 1010 1200 1430 1670 1825 7 Front Support, Flue Collector 10662101 10662102 10662103 10662104 10662105 10662106 10662107 10662108 10662109 8 T ile Cover , Front & Rear 10661501 10661502 10661503 10661504 10661505[...]

Pump Rotating Sections and Repair Parts Check pump assembly on heater for H.P . rating and find correct Laars part number from table below . Description 1/4 HP 1/3 HP 3/4 HP Pump Rotating Assembly, B&G , 1522 w/3 “ IMP , Bronze, 1P A0048700 —— —— Pump Rotating Assembly, B&G , Series 90 w/3 “ Impeller , 1P A0077100 —— —— [...]