The Whirlpool Flamelock water heaters class action suit pertains to Flame Lock water heaters beginning with model # FN. I have a newer Flamelock model # UG 1J5040T3NV with the same lemon issue. Purchased 1/2008. As of 5/2009 it has gone through replacements of the thermostat, pilot assembly/gas valve and not one, but two, thermocouplers. In addition, my family has experienced about a dozen days of late night showers while waiting for the water to re-heat after the pilot light had to be re-lit, plus four days of cold showers or sponge baths due to having no hot water at all when the system just wouldn't re-light. Repairs are not necessarily same day whenservicers are busy or need to order parts. Whirlpool water heaters provide job security for plumbers so they're not likely to discourage the purchase. Later, they just refer you to the servicer for 12 yr warranty! Yes, whirlpool will repair it, but I just can't stand another 10+years of repairs, so I'll be looking at my options for getting rid of this clunker. My prior heaters never had this problem. This model is sold through LOWE's...it's the most regretful purchase I've ever made from them. Moral of story: Research before you buy, even when under the gun for a fast replacement...because you'll end up with lots of repairs.

The thermocouple could be 'weak' and not putting out enough current. In the light position there is usually extra gas supplied to make lighting easier (more like the ignite level than the smaller standing pilot level). The extra gas is hot off when you move to the 'on' position, the thermocouple no longer has enough output, and out everything goes.

No spark? Does it click? You can try using a fire place lighter and manually lighting it. You'll need to replace the spark ignitor, but at least you can get one tank of hot water for a shower before you hit the box store for the part.

Thank you for your ideas. However, none of those things apply---cover only goes on one way; nothing blocking air; water heater is in basement and new furnace takes air from outside; no insulation blanket; water heater has its own flue; not at high altitude, etc. After I posted this I remembered a plumbing supply place that caters to pros and DIYers so I called them. They said it sounded like a thermocoupler issue. When the supervisor arrived he took a look--it wasn't completely attached! He replaced it, etc., and now it seems to be fixed.