Lochinvar Gas Water Heaters
Review and Buying Tips

Lochinvar gas water heater

Check out the Lochinvar gas water heaters for an efficient water heating, types, and features.

Buying and installing a Lochinvar gas water heater can make the difference in your home. No matter the size, gas models can, in general, heat the water fast and easily keep up with the high demand for hot water than electric. The operating costs are lower, making them more affordable.

Lochinvar gas water heaters for residential hot water production, are available as indirect water models, manufactured housing models, and standard type models:

  • High Efficiency
  • Ultra-Low NOx
  • Power Vented
  • Power Direct-Vent
  • Balanced Flue Direct Vent
  • Double Duty
  • Manufactured home


A great number of the above Lochinvar gas water heater models meets or exceeds the energy efficiency standards, NAECA and ASHRAE.

Also, they meet ANSI standards required for residential gas-fired water heaters. This is done by implementing the combustion technology that protects from the accidental ignition of flammable vapors outside the water heater. Shield Combustion System is Lochinvar's patented system that meets the above requirements.

Thanks to the Shield Combustion System, Lochinvar gas water heater is the high-efficient unit, providing great benefits to its customer and the environment.

The main components for all Lochinvar gas water heaters with the FVIR technology are the Lock-Shield Flame arrestor plate, made of the stainless steel, low NOx burner, and resettable thermal switch to protect the water heater from the heat created by flammable vapors.

Lochinvar models that are equipped with the pilot light to lit the main burner are using the piezo igniter while some can come with an electronic spark ignition or hot surface.

To protect the Lochinvar water heater tank, glass lining is applied to the inner tank surface and magnesium high capacity anode rod is added for protection against corrosive water action. Magnesium anode rod is found in the majority of Lochinvar models.

Additional elements that are added for your convenience are the temperature and pressure relief valve as a safety feature and brass drain valve for easy fill and drain.

Lochinvar provides a 6-year warranty on the tank and parts with an option to upgrade it to 10 years.

High Efficiency

High-efficiency Lochinvar water heaters are designed as FVIR models with the heating power from 30,000 to 85,000 BTU, and sizes from 30 to 100-gallon capacity, with a short and tall configuration.

LTN030G-EF, LTN040G-EF, and LTN050G-EF are the three high-efficiency models with the EF of 0.62 and recovery rate of 34-43 GPH for 90 F temperature rise.

Models LTN040G-4, LTN050G-4, and LTN051G are high input models, which allow them to provide 50,000 and 65,000 BTU and 53 and 67 GPH for 90 F temperature rise.

Models LTN065G, ETN100 and LTN051G are models that can be used for both water and space heating as they have the side tapping for space heating applications.

Ultra-Low NOx gas water heaters

Ultra-Low NOx residential gas water heaters produce less than 10 ng/j of NOx gases, thanks to the newly designed radiant burner system.

Lochinvar water heater with ultra-low NOx is an atmospheric unit that works on natural gas only. It is designed as short and tall, with an offer of the most popular sizes of 30, 40 and 50 gallons. With a low emission gas burner design, they meet SCAQMD requirement.

Ultra-low NOx Lochinvar water heater features the Honeywell gas control valve that allows better and accurate control of the improved economy. It also allows easy diagnostics and troubleshooting with the installed LED display.

Ultra lox NOx models are also available as high-efficiency models with EF 0.62 and 2" thick foam insulation and with the sizes of 30, 40 and 50 gallons. Lochinvar also builds high input models whose 40 and 50-gallon water heaters have the high recovery rate of 53 gallons per hour on 90 F temperature rise.

Power vented water heaters

Power vented residential gas water heaters are designed in several sizes; from 40 to 75 gallons and with the power range from 40,000 to 76,000 BTU.

Lochinvar water heater with the power vent is using the environment-friendly low NOx burner which is part of the standard FVIR technology. Only the model LVN076, a 75-gallon water heater is not required to meet FVIR requirements.

Venting is very simple; power vented water heaters are using 120 VAC blower fan and the sidewall flue termination where the pipe is made of the cheaper PVC or CPVC material. Vertical venting is also an option; and based on the size of the water heater you will use 2, 3 or 4" vent size.

All the models are using standard 3/4" NPT water connection and models LVN052G, LVN065G and LVN076 are constructed with the side connection, so they can be used for space heating also.

Power vent water heaters come with the electronic spark ignition, have the heat trap nipples installed to reduce the heat loss in piping and two models; LVN052G and LVN065G are equipped with the 2" thick foam insulation.

FVIR model LVN065G has the highest recovery rate, 75 gallons per hour with the 90 F temperature rise. It provides 70,000 BTU and has the EF 0.65. Other FVIR models with the energy factor of 0.62 or higher meet the requirements for the Energy Star approval.

Power direct vent gas-fired water heaters

Lochinvar water heater with the power direct vent utilize the sealed combustion gas burning process to provide the fast recovery and high first-hour rating, and it covers three models; 50, 65 and 75-gallon tank size. Gas input is in the range from 60,000 to 75,000 BTU while the recovery rate is from 65 to 75 gallons on 90 F temperature rise.

This is a 2-pipe vent system, where one pipe is used for products of combustion and the other for the fresh air intake, needed for gas combustion.

As it is still equipped with the FVIR technology (except 75-gallon) they have the low NOx gas burner. To light the gas inside the combustion chamber, power direct vent water heater is using the hot surface ignition.

Balanced Flue direct vent

Lochinvar water heater is also available as the direct vent unit that features the sealed combustion and concentric vent system. The concentric or co-axial vent draws the outside fresh air through the outer pipe and through the inner pipe it runs the products of combustion out.

The advantage of these vent systems is in the flexible installation as it can rotate 360 degrees. The vent pipe and vent cap are included with the purchase of the unit.

Available models are with capacities of 40 and 50 gallons and maximum gas input of 38,000 and 42,000 BTU. Both models are using low NOx burner and the pilot light ignition.

Double Duty

Double Duty water heaters are designed for those homeowners who want to use one tank for both water and space heating. You can choose models from 50 to 75 gallons’ tank size that are producing 63,000 to 76,000 BTU.

Lochinvar's Double Duty water heater is heating water indirectly using the Therma-Tube Anti-Leak heat exchanger. This double wall heat exchanger is immersed in the tank, and it separates domestic water and heating fluid.

You can also choose between the atmospheric and power vented model which comes with the option for vertical and sidewall run.

All the previous models, mentioned above, have the magnesium anode rod installed for corrosion protection. Double Duty models are equipped with the tougher aluminum anode rod, which reduces the risk of rotten egg odor when the anode rod deteriorates.

Manufactured home gas water heater

Lochinvar water heaters that are specifically designed for manufactured homes, can be found with the capacity of 30 and 40 gallons and gas input of 30,000 Btu/hr for both models. A conversion kit is supplied with the unit, so it is convenient to convert the water heater from using the natural gas to LP or propane gas, but with a recommendation to call a technician for this job.

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