Powervent gas water heater stopped working

I installed this Sears 153.332960 power vented heater as a replacement and it ran perfectly for 2 weeks. Wife then heard unusual (loud) sounds during operation, probably from the burner area, and turned it off electrically. She was too scared to worry about exactly where the sound was originating! Now, it will not run at all. When the heater is switched on, all LEDs light up, dim slightly and after 2 sec there are two 'clicks', the lights go out and nothing more happens.

The power vent does run when powered directly 'off-line' and sounds normal. Apparently it is not being called for by the control circuit as I think that's the very first step of the on-cycle. Can someone confirm that?

The 'new' unit is actually 7 years old so no warranty. When I bought it, the cost of the whole water heater was only about $100 more than the replacement part I needed (failed power vent). I grafted the fan only of the new power vent system onto my original water heater where it performed without incident for those 7 years. Recently the old tank developed a leak around the relief valve so I replaced it with the unused tank and its original, now used, power vent. The unit fired right up and ran the two weeks I mentioned earlier.

I'm wondering if there's anything else I can test myself!

Thanks for any help,

John

As I understand it the LED's on this thing are supposed to give you a diagnostic code. Do you still have manual?
I've also heard that if unit is on GFI circuit it can act screwy, but old unit was working. And this one ran for a while.
Check the positioning and condition of flame sensor. Check that none of your grafted on rewiring has come loose. Check that vent pipes are all connected. Proper air flow into and out of flame chamber.
can your wife describe the unusual loud sound a bit more precisely? Bang, clank, click, hiss, rumble, singing?

Thanks for your interest!

For all lights lit, manual offers "Problem with internal circuit" with Solutions " 1. Power cycle for 10 sec" and "2. Replace gas valve".

On GFI, supply circuit does not have GFI, and yes, worked for 2 weeks.

Wiring seems good ; all venting intact. I will probably next disassemble the power vent system to check on fan operation, clear pathways inside the heater and out to fresh air etc. Doubt there's any air shortage in the pre-1800 basement!



The flame area looks clear. The front baffle is currently removed. The igniter and flame sensor (bent) look OK but what do I know. I will try to post a picture.

I was able to reconnect the vent fan to the old heater control system and it started right up when the heater was provided 110V. I can't easily reconnect the gas and prove total function. I understand the 'new' heater (2005) may have more safety interlocks that the original (?? 1992) so I can't push comparison too far.

Noise: I hear only what I expect for quality (steady roaring of the fan) but we disagree on quantity of noise. She is sure it's much louder than before but isn't sure there is/was any new sound.

"Problem with internal circuit" That could actually be "external" wiring, not connecting to internal properly or actual internal, I really dunno how much "integrated" circuitry this thing has.
"Power cycle for 10 sec" P confess I don't even know what that means. Can you overide it for 10 seconds some how?

Replace gas valve. This could be related to bent sensor or actual valve. If bent on outside could be broken on inside. Some folks report success in just sanding, cleaning, sensor. Still got old parts? Compare costs of replacing valve and sensor, canabalize. Or as you more delicately put it, graft.
( I never throw anything away without stripping it, right down to screws.

May be plenty of air in basement is it getting to flame chamber?

"roaring of the fan" could it be too much? Sucking air past flame, even blowing it out?
My bet is on bent sensor, gotta admit this new fangled thing is beyond me heating water in kettle on stove. But a gas flame starting then stopping, or working then sudenly not working, is usually a sensor ( thermocouple or whatever) problem. If it doesn't get hot within specified time it shuts gas off, if it is totally shot it won't let gas turn on.

I'm about out of ideas, need a younger guy familiar with new technology to take over.

Thanks, notMrjohn, for good questions!

My present conclusion is that this was a false alarm. It took a while to figure that out because turning on the vent fan is NOT the first step in the on-cycle for a thermostatted device like this, it's "Is the thermostat calling for heat/cooling?" Early on I had turned the thermostat down, based on actions for safety listed in the manual (when I thought something was seriously wrong, possibly with gas supply and ignition). So all my efforts to make it run were stalled at the first step, "do we need heat" to which the thermostat answered "no"! I think my first attempts to start it (before turning down the T-stat) were while it was still hot from normal if noisy operation so the thermostat had the same negative effect. It seems to take several hours to cycle on if no water has been drawn.

It's running for a couple of days now. We can't agree if the noise of the powervent is really excessive or not!

Thanks again!

John

PS I take 'power cycle for 10 sec' to mean turn electric supply off for at least 10 sec., then restart.

So we fixed something that wasn't broke.
Turning the thermostat up is sorta like the "Did you push the button marked ON?" Or Is it plugged in? At least we didn't get to the stage of calling in repair man to flip on switch, that actually happens sometimes. Well, I learned something here. there's more than one ON switch, I increased my personal"DUH!" count. I was all concerned with tricky problems of heat sensors and over awed by hi-tech power vent and forgot all about simple basic things.
Then again, just the messin around mighta fixed it, mebbee you got the Magic Touch. My dad had that, somethin would be broken, he'd open it up, take it apart. Sometimes he'd mumble, "I don't understand all I know about this," or "There's nothing fixable here," the latter especially as printed circuits and chips came along. He'd put it all back together, and the thing would work!

"'power cycle for 10 sec' to mean turn electric supply off for at least 10 sec., then restart." sounds good to me. Owner's manuals should be writ the way folks tock. "Turn it off, have a cup of coffee, turn it back on."

Here's an old and bad joke. Fella hires Rafe, an old boy from way back in the Piney Woods, to cut down some trees. Early in mornin he shows the trees to Rafe and gives him new chain saw, then leaves, returns that evenin', only two trees cut down. Rafe says the saw is right purty but don't cut very fast. Fella gives the rope a quick jerk. Rafe jumps back, asks , "What's that noise?"