Laars Mighty Therm VW-PW (Sizes 175-400) - Installation, User Manual

Installation, Operation and Maintenance Instructions Document 2051FH0147500FInstallation, Operationand MaintenanceInstructions forMighty ThermVolume W

LAARS Heating SystemsPage 109. Remove the four screws that fastens the metalchannels covering the capillary tube on the rightside of the jacket, and l

Mighty Therm Volume Water HeatersPage 1140. On indoor installations (sizes 175-250), insert thedraft hood switch plug into the receptacle on theleft s

LAARS Heating SystemsPage 12Heat Flow Pressure* Water TempExch. Water Rate Drop RiseModel Passes Categorygpm L/s ft. m °F °C175 2 Soft 22 1.4 5.8 1.

Mighty Therm Volume Water HeatersPage 13Figure 22. Hot water supply with horizontal tank.Note:Heavy line indicates heater-to-tank circulation loop.Fi

LAARS Heating SystemsPage 14valve is directed to an open drain and protectedfrom freezing.2. Install a properly sized thermal expansion tank onthe col

Mighty Therm Volume Water HeatersPage 157. Check the oil level in the pump before startingthe heater. Oil the pump every three months. Oilpumps locate

LAARS Heating SystemsPage 1610. The correct burner manifold gas pressure isstamped on the rating plate. The regulator on thegas valve is preset at the

Mighty Therm Volume Water HeatersPage 17 WARNINGSVent pipes, drafthoods, and heater tops get hot!These surfaces can cause serious burns. Do nottouch t

LAARS Heating SystemsPage 18Figure 26. Typical example of wiring schematic, System 1.

Mighty Therm Volume Water HeatersPage 19Figure 27. Typical example of wiring schematic, System 12.

LAARS Heating SystemsPage 2TABLE OF CONTENTSSECTION 1.General Information1.1 Introduction... 31.2 War

LAARS Heating SystemsPage 20hot water in the application.After a setting has been chosen for the tanktemperature control, set the heater temperature c

Mighty Therm Volume Water HeatersPage 21Electronic Pilot Standing PilotFigure 29. Flame patterns.Example, Metric units: If the heater’stemperature c

LAARS Heating SystemsPage 223.5 Hi-Limit Switch CheckoutAfter running the heater for a long enoughperiod, bring the water temperature within the range

Mighty Therm Volume Water HeatersPage 23If the gas valve is found to be defective, replaceit by following these instructions.1. Turn off electrical po

LAARS Heating SystemsPage 244.3 HEAT EXCHANGER4.3.1 Inspecting the Heat ExchangerTo check the scale buildup, periodically inspectthe tube having the h

Mighty Therm Volume Water HeatersPage 255. Attach one end of the manometer hose to thefitting on the gas valve and the other end to themanometer.6. Op

LAARS Heating SystemsPage 26Testing the transformer requires an AC voltmeterwith a 50 volt (V) range. Test the transformer usingthe following procedur

Mighty Therm Volume Water HeatersPage 275.2.4 Testing the Manual ResetHi-Limit SwitchTo test the manual reset hi-limit switch (seeFigure 36):1. Touch

LAARS Heating SystemsPage 285.2.7 Testing the FuseTo test the fuse:1. Clip a lead of the voltmeter to the groundingterminal.2. Touch the other voltmet

Mighty Therm Volume Water HeatersPage 29ThermocoupleThermocoupleAdapterGas ValveMillivoltMeterPilotFigure 41. Testing the pilot thermocouple.2. Clip

Mighty Therm Volume Water HeatersPage 3SECTION 1.General Information1.1 IntroductionThis manual provides installation, operating, andmaintenance instr

LAARS Heating SystemsPage 302. If everything appears all right, measure flamesensing current by connecting a direct current(DC) microamp meter between

Mighty Therm Volume Water HeatersPage 31Nat. Stdg Pilot, (Model 250) ...V0073300Nat. Stdg Pilot, (Model 325-400) ...V0049900LP

H0147500F800.900.9276 • Fax 800.559.1583 (Customer Service, Service Advisors)20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355

LAARS Heating SystemsPage 4number for the drafthood is on the heater rating plate.Follow this procedure to make the conversion:a. Remove the top fille

Mighty Therm Volume Water HeatersPage 5d. Disengage the flue transition ring from the stackextension and place it on top of the collectorassembly as s

LAARS Heating SystemsPage 6Figure 11. Standard base for combustible floor.Figure 13. Typical roof mounting with standardcombustible mount base.Figure

Mighty Therm Volume Water HeatersPage 7Method 1:Two permanent openings, one commencingwithin 12" (30 cm) of the top and one commencingwithin 12&q

LAARS Heating SystemsPage 8supply or reverse the natural draft action of the ventingsystem. This could cause flue products to build up inthe heater ro

Mighty Therm Volume Water HeatersPage 9Figure 15. Heat exchanger reversal.Figure 16. Flue collector Holddown Clamps.