Re: No spark to water heater Reply #25 – October 28, 2016, 04:48:02 pm Quote from: Andy Baird - October 28, 2016, 01:25:39 pmWell, now it's my turn: I have a water heater problem of my own.Symptoms: when switched on, green light, but no red. No ticking from the ignitor. No status light on the Dinosaur controller board. Open-circuit voltage at the edge connector on the board: maximum of a hundred millivolts or so (varies) between any two contacts. Pretty clearly the board isn't getting the 12 V power it needs.What I've done: cleaned all contacts with Cramolin (old name for DeoxIT). Tested thermostat, ECO (emergency cut off) and thermal cutoff--all had good continuity. Checked switch in stove hood panel; appears good (has 13 V on input side; good continuity when switched on).It seems as if the 12 V power that should be coming from the panel switch (via a brown wire) to the water heater controller board isn't getting there. But how to trace that wire, and where/how it could be broken, have me stymied. Any ideas? I'm gettin' tired of showering with water heated in the teakettle!Andy,Maybe you've already done some or all of this, but have you taken the brown wire loose at both ends and checked its continuity? That could eliminate the need for searching for a break in the wire. Though the switch in the hood 'appears' good, could you jump it? Corrosion or a weak contact could allow it to ohm okay but not pass adequate voltage to the board. If there's no improvement when it's jumped, at least you'll be certain the switch is okay. Any chance of a loose or corroded ground wire that is preventing a good path to ground? Just a couple of thoughts. Good luck!
Re: No spark to water heater Reply #26 – October 28, 2016, 05:41:40 pm Good suggestions from Judie, Kevin and Bill--thanks! It turns out that 12 VDC (on that brown wire we were talking about) enters the water heater system not at the controller board's edge connector, but rather at the "hot" side of the thermal fuse, via a .187" female push-on connector. From there it passes through the emergency cutout and the thermostat before reaching the controller board. (Ground is made via a short wire to the heater's heat deflector, and thence to chassis ground.)I had tested continuity of these three components, so I was certain that if it went into the thermal fuse, it would end up at the controller board. Fortunately, I keep crimp-on .187" connectors in stock. So I jumpered 12 V to the thermal fuse--not bothering to jumper ground. Lo! The heater started right up.Conclusion: there's probably a break in the brown wire somewhere between the stove hood switch and the water heater. My next step is to look at the back of the water heater and see whether anything is amiss there, but that will require moving some furniture, and I don't feel like doing it tonight. I also test the brown wire's and the switch's continuity as Bill suggested.At least it's not the water heater and it's not the Dinosaur controller board. That's good news.
Re: No spark to water heater Reply #27 – October 28, 2016, 05:57:21 pm Andy, my circuit diagram shows the 12v supply going first through the thermal fuse then the thermostat, then to the board. Either check continuity for each (they should be closed) or bypass them one at a time with a jumper, and see if the system wakes up. A green light with no red and no attempt to light leads me to believe you have a thermostat stuck in the open, or hot, condition.Ken F in NM(Oops - I see you solved it - never mind.)
Re: No spark to water heater Reply #28 – October 29, 2016, 01:32:49 am Andy, one suggestion, if you have a possible break in the brown wire from the switch to the unit. Think about if you did something or moved or change anything in your LD? Some times something we do or change causes the problem and that's where you will find it. ~Liam 98 ~ MB
Re: No spark to water heater Reply #29 – October 29, 2016, 06:36:38 pm Problem solved. Liam, you hit it on the nose! Turns out that when a friend and I installed a bracket for a curtain, by chance we put a screw right through two of the wires that go to the water heater, cutting them. The wire bundle in question runs inside the aft wall of the midbath's wardrobe.My friend pointed out the connection between installing the curtain rod a couple of weeks ago and the water heater stopping at about the same time; it probably would not have occurred to me. We carefully removed one of the screws from the bracket, and yep, there was a little bit of blue wire insulation on the threads. Looked like we had found our culprit!I cut out a 3" x 6" rectangle of the paneling inside the closet to get to the wires (go MultiMaster!), butt-spliced them, and all's well again. I still have to cover the access hole I made--but it's inside the closet up by the ceiling, so it will hardly ever be seen. In other words, the patch need not look like original equipment. :-)Many thanks to all for the good suggestions!
Re: No spark to water heater Reply #30 – October 29, 2016, 07:21:52 pm Quote from: Andy Baird - October 29, 2016, 06:36:38 pm"...by chance we put a screw right through two of the wires that go to the water heater, cutting them.......We carefully removed one of the screws from the bracket, and yep, there was a little bit of blue wire insulation on the threads. Looked like we had found our culprit!..."Andy,Better a wire than a water line I suppose. One more reason I'll stick as close to factory as possible.Good luck on your patch work. Maybe a Velcro'ed panel could do the job in case you ever need to get back there again.Kent
Re: No spark to water heater Reply #31 – October 29, 2016, 11:13:04 pm I usually drill a pilot hole and probe with a wire like a coat hanger, but not always and have regretted it on occasion... ~Liam 98 ~ MB
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Topic: No spark to water heater (Read 777 times)
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