any feedback regarding a whirlpool nd40t62-403 pilotless electronic ignitions

The Tank any feedback regarding a whirlpool nd40t62-403 pilotless electronic ignitions

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    Sorry hit wrong key. Anyone have experience with this model? Is the electronic ignition worth having? Will it save over pilot models? Is it significant?




    This is AO Smith water heater with flue-damper and Honeywell electronic self-diagnostic control

    Water heater has EF .67 and estimated cost of Natural Gas per year = $272 makes this an ordinary water heater with no anticipated savings vrs other .67 water heaters.
    However AO Smith Conservationist model has EF of .62 which is most typical of ordinary non-dampered residential water heaters.
    Savings might be $14 per year between .67 vrs .62 assuming new water heaters in peak condition.

    Water heater plugs into 120V outlet. Best to have a dedicated circuit with nothing else on the line, including fluorescent lights. Power surge can knock out gas control that is plugged into outlet so install surge protector. Simple power outage can cause surge. Check outlet with circuit analyzer to ensure proper polarity of outlet. Water heater must be grounded or gas control will not operate. Do not use extension cord. Unit comes with 10 foot cord.

    Surge protector might cost $14 so first year’s savings is gone.

    “Electronic ignition operates with an automatic pilot relight systems that shuts off during standby mode which reduces gas consumption.”
    Does this feature save money? Since all costs are energy, and the savings is $14 per year, the real question is ‘will the system need to be repaired during the brief 6-year warranty period?’ And what is cost of EF.62 water heater?

    Parts list is shown in manual on AO link above, and all parts are replaceable, and easily accessed using instructions in product manual.

    AO Smith makes good heaters. And they make lemons. Same as cars and dishwashers.
    My local plumbing supply sells AO Smith. And they have a pile of worn out heaters that lasted a long time. And they have a small pile of 2-3 water heaters that had problems, awaiting return orders from Smith.

    The flue-damper series water heater can be reset ‘by qualified technician’ after FVIR or high temperature event. Energy cut off limit 160-189 degrees F. 1-800-527-1953

    Today’s water heaters need plenty of fresh air, and air intake located at bottom of heater needs to be kept clean.

    Flame arrestor must be cleaned with vacuum cleaner by removing burner.
    The manual has good instructions.
    Download manual on AO Smith link above.

    Installation is typical: Water heater must be set 18″ above floor. Do not install in dusty environment. “Area must be free of corrosive household chemicals and flammable materials. Water heater not located near air moving device (such as room vent fan).

    67 gal first hour delivery for 40 gallon tank makes the flue-damper series an average modest heater.

    The Honeywell gas control is proven on the market, and is replaceable.
    Blinking-light status code is good start-point for troubleshooting.
    Manual has good troubleshoot walk-through
    Some models have black knobs.

    Thermal cutoff located on combustion door is resettable, and will trip if vent is blocked or insufficient combustion air. The thermal switch is in addition to the FVIR system. This is typical of Whirlpool/AO Smith water heaters today.

    Most the AO Smith burners can be taken out, cleaned and re-installed without buying replacement door gasket. The burner and combustion door are removable in 1-piece and held in place by two hex screws.

    It appears to be a good water heater.
    AO Smith is one of the big-three manufacturers.


    Thanks for the detailed response. I compared a few models and was interested to see if anyone had any experience (cost savings) running a tank heater without a standing pilot. I know that in theory it should use less gas however if it is a minimal savings that does not justify original cost and potential problems with a slightly more complicated system.

    I purchased a rheem that had a magnesium rod and brass drain valve as standard and was self cleaning (not sure if it really matters)

    This was for my elderly parents home and I came to the conclusion that a simple as possible would be best.

    Thanks again


    Randy Schuyler

    It may use less gas, but the gas that a pilot uses is mostly not wasted. The heat it creates does heat the water in the tank, in some measure. There is a flue baffle that slows down the exhaust gases as they rise through the flue so that more heat is transferred to the water.

    Randy Schuyler

    Larry Weingarten

    Hello: Although nobody in the industry likes it and it’s being revised, energy factor (EF), can be sort of a useful tool for comparing similar heaters. In theory it takes into account all the design differences to arrive at a number. It is not precise. I wouldn’t be concerned by a point or two. And, yes, simple is better 😉

    Yours, Larry


    Randy, Larry
    Thanks for the responses.

    I purchased a Rheem 22v40f1 after reviewing various factors and keeping in mind that simpler is better over the power damper and electronic ignition. It has a Magnesium anode with resistor and brass drain valve also claims to be self cleaning. Claims to deliver 73 gallons first hour. I will check rod every year from two year mark on and replace based on information gleaned from this site.

    Thanks again


    You are going to need guys like me to maintain and repair this heater. Most plumbers don’t have the skills necessary to repair these heater much less the parts on hand. I’ll charge you 200.00 for the first hour but I will have the part on the truck and make the repairs needed without any guesses. Some thing to consider when getting fancy. 🙂


    EJ, you are talking about the flue-damper series.
    What is the most common point of failure with this type heater?

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