For your safety: this product must be installed 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 d...
Laars heating systems page 2 section 1. General information 1a. Introduction ................................................... 3 1b. Heater identification ..................................... 3 1c. Flow requirements ...................................... 4 1d. Water chemistry .......................
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 proceed...
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 circu...
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. I...
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 combustio...
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...
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 individu...
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 th...
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 ...
Mighty therm volume water heater page 11 figure 11. Hot water supply system (model vw & pw). With vertical tank with horizontal tank 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 buildin...
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 circula...
Laars heating systems page 14 figure 16. Two-temperature hot water supply system (model vw or pw). With vertical tank with horizontal tank 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 -...
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 - servic...
Laars heating systems page 16 2i. 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 he...
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...
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 plac...
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 temperatur...
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, dampe...
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 p...
Laars heating systems page 22 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 1010 1200 1430 1670 1825 1 t op panel assembly 10535701 10535702 10535703 10535704 10535705 10535706 10535707 10535708 10535709 2 s p acer , flue collector — — 10540800 1...
Mighty therm volume water heater page 23 figure 22. Parts identification. Note: temperature 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 well...
Laars heating systems page 24 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 1010 1200 1430 1670 1825 2 1 t ile, heat shield/s pcr , frt. & rr . 10560100 — — — — — — — — — — — — — — — — (2) 2 2 t ile, heat shield/s p acer , front —— 10547901 10547...
Mighty therm volume water heater page 25 figure 23. Tile assemblies..
Laars heating systems page 26 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 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 e...
Mighty therm volume water heater page 27 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 1010 1200 1430 1670 1825 6 4 safety gas v alve, on-of f, t wo s tage (nat) v0046600 v0046600 v004600 v004600 v0046700 v0046700 v0046700 v0046700 v0046800 6 5 s...
Laars heating systems page 28 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 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 exten...
Mighty therm volume water heater page 29 figure 21. Outdoor parts..
Laars heating systems page 30 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 1010 1200 1430 1670 1825 1 t op panel assembly 10660701 10660702 10660703 10660704 10660705 10660706 10660707 10660708 10660709 2 rear windshield 10658101 10658102 106581...
Mighty therm volume water heater page 31 k e y description model model model model model model model model model n o 5 0 0 6 0 0 7 1 5 8 5 0 1010 1200 1430 1670 1825 7 front support, flue collector 10662101 10662102 10662103 10662104 10662105 10662106 10662107 10662108 10662109 8 t ile cover , front...
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...
