To Next PageTo Next Page
Need help?Do you have a question about the Laars Mighty Therm and is the answer not in the manual?
Provides information for installation and operation of Laars gas-fired hydronic boilers and water heaters.
Explains how to identify the boiler model using the rating plate information.
Details the need for continuous flow through the heat exchanger for proper operation.
Specifies required clearances for maintenance, inspection, and air circulation.
Guides on locating indoor heaters for adequate clearance, drainage, and protection.
Ensures sufficient air for proper combustion and ventilation of the surrounding area.
Details air supply openings for conventional ventilation of heater rooms.
Addresses air supply requirements when using forced-air ventilation systems.
Covers requirements for connecting the flue outlet to a clear, unobstructed vent.
Provides steps for safely removing an existing heater connected to a common venting system.
Provides guidance for installing heaters outdoors, considering environmental factors.
Details instructions for connecting the gas supply and piping to the heater.
Covers requirements for grounding and wiring the heater according to electrical codes.
Provides general guidelines for water piping installation, including valve placement and relief valves.
Specific piping instructions for Laars PH model heating boilers.
Addresses systems with variable flow and recommends primary-secondary pumping.
Specifies minimum system pressure requirements for closed and open systems.
Guides on connecting boilers to air conditioning systems and preventing water mixing.
Details considerations for using the boiler for both space and potable water heating.
Lists requirements for piping, including low water cutoff and expansion tanks.
Provides a step-by-step guide for filling the heating system with water.
Specific piping instructions for Laars PW model water heaters.
Discusses water quality, scaling, corrosion, and their impact on the heater.
Covers piping requirements for two-temperature systems and tempering valves.
Explains water expansion during heating and solutions for pressure buildup.
Details pump sizing and pipe fitting requirements for circulation loops.
Emphasizes maintaining adequate water pressure to prevent pump and heater damage.
Provides guidelines for installing storage tanks, ensuring structural support and accessibility.
Explains the design for maintaining tempered water circulation at desired temperatures.
Overview of general controls and safety devices for heater operation.
Describes the proved hot surface ignition control and its safety features.
Details the 120 VAC silicon carbide igniter used for ignition.
Explains the function of the pressure switch in proving combustion air flow.
Discusses aquastats used to control service water temperature in PH and PW heaters.
Covers standard and optional manual reset high limit switches for safety.
Describes the flow switch that shuts down burners if pump fails or flow is reduced.
Explains the low water cutoff that shuts off the heater if water level drops.
Provides crucial safety warnings and steps before operating the appliance.
Details the sequence of operation when the heater calls for heat and cycles on/off.
Explains how to test the high-limit switch functionality by adjusting its setting.
Provides a step-by-step guide for safely starting up the appliance, including gas leak checks.
Step-by-step guide for safely lighting the burner, emphasizing no manual lighting.
Instructions for safely shutting off the gas supply to the appliance for service.
Guidance on setting operating temperature and high-limit controls.
Guidance on setting temperature and high-limit controls for hydronic boilers.
Instructions for adjusting temperature controls on water heaters and recommended settings.
General maintenance advice, including oiling pumps and blowers, and checking flames.
Instructions for inspecting and servicing the combustion air blower and its housing.
Guidance on checking the heat exchanger for fouling and potential combustion air/venting issues.
Steps for externally cleaning the heat exchanger, including disassembly and draining.
Procedure for internal cleaning of the heat exchanger, including removing headers and using cleaning kits.
Recommends annual checks of gas and electric controls for safe operation.
Detailed steps for removing, cleaning, and inspecting burners and related components.
Explains the heater's operational sequence to aid in troubleshooting.
Guidelines for checking electrical components and troubleshooting issues.
Provides guidelines for checking common electrical issues that prevent heater operation.
Detailed procedures for troubleshooting electrical components, focusing on safety.
Troubleshooting guide for mechanical components and common issues.
Addresses causes and remedies for pressure relief valves leaking.
Troubleshooting conditions related to water flow, system pressure, and pump issues.
Diagnoses issues related to combustion air, venting, and gas pressure.
Identifies potential causes of water dripping in the firebox, such as tube rupture.
Lists parts and order numbers for jacket and combustion chamber components.
Lists parts and order numbers for water system components, including tubes and tanks.
Lists part numbers for electrical components like switches, relays, and control panels.
References figures for gas train components and their part numbers.
References figures for burner tray components and their part numbers.
Lists parts and order numbers for outdoor jacket components.
General