I like the Rheem/Ray Pak (same heater, different distribution channels) as a replacement, such as in your situation.

That's a very serious failure you experienced and very unusual to boot.

The symptoms you describe sure sound like the gas flow may not have been adequate. Gas flow needs to be tested with the system in a static/off and dynamic/on state. I'd want to know how the tech determined these the dynamic on flow.

Things I'd look for would be the meter's size, the length of the run, the supply pipe size, and the length of 3/4" pipe connecting the heater's regulator to to the supply pipe.

I suppose it's possible a spider's or moth's nest hatched and baby spiders or caterpillars made webs that clogged things up for some burners. Another possible cause would be a gas regulator failure. It's rare but it happens. It's also possible a safety circuit device shorted, a rodent got in and did some damage...

There really isn't any way for us to determine it without seeing the unit and going CSI on it.

Scott

Scott I have seen a few of these Legacy heaters at my distributor that experienced the same problem. Low gas pressure/flow can do a lot of things, but shouldn't melt the burner tray on a new heater.

How long have we seen older heaters with low gas pressure not suffer the same fate?