I need a little help on this one.
Client has in-ground...40K with attached spa.
Here's the story (short version)
I was hired to rewire the pool equpt. area. I did and everything works well. In testing the pool's heater http://www.poolcenter.com/parts_heat...x_plus_pg1.htm (this unit has top baffle #39 and in/out water ports are on the SAME side as the electronics (opposite the diagram shown)) I noted that when I called for heat (filter running - stat SW to pool - temp dial past current temp) I would hear a clicking and the red service light would come on. I thought of gas......gas was fine. I thought of electronic pilot...confirmed it was working. Did not test hi limits because I had to go.
Fast forward a few days and I am back finishing up a few things. I try the heater again....fires right up and works like a charm. Turned unit off.....than back on 30 min later...works great. I advised the home owner it was oddly working and we'll see how things go. Few days later I am back and tested it again just for SnG's! It's on for a few minutes than off....back on....now I am thinking Hi limit all the way.
Today, I open the control panel and guess what I find? An IID http://www.parts4heating.com/Product...uctCode=S8600F that has melted.
So, instantly I think...ohhh, it's bad, order a new one and all is well!!
hmmmm......ok, so I have a degree in electrical engineering, but it's been a while since I did component level work. However I do alright.
Here's the issue I am having:
As you can see from the link, the picture of the IID (mine looked exactly like that) is a simple S8600F Nat gas.
Imagine taking that controller and a heat gun and just go over it over and over again until all the plastic has melted to the contours of the components....that's what I have here.
So just a bit ago I carefully broke away all the hardened brittle plastic to examine the board. I saw not one burnt trace, not one burnt component, no trace of an oder when electronics components fry. It should also be noted that the molex plug and two grounds as well as the 24vt and coil ignighter (thin blue wire) was not really damaged. Damaged in the sense of a shorted wire that is. I saw some slight overheating, but not enough to break the wire jackets or deform any part of the crimp connectors of the molex plug.
So here's where I could use a bit of experience.....
Is flame getting to an area that it is not supposed to and heating up this IId to a point where it melts the casing? Is it possible the internal transformer shorted itself out and that generated the heat to melt the case?
Would it be wise to go back and open up the shell and look for overheating marks on the back side of that front panel?
It should also be noted that the stat controller board appears to be in working condition. I noticed no signs of damage or stress. All the LEDS work, the dial temp pots appear to work, and that tells me the water thermistors are working well too. because a call for heat is happening, but the IID ain't having it.
I hope I gave enough details and your responses are greatly appreciated. BTW, I am a master tankless water heater installer. I train installers on correct methods of installation as well as AHJ's on what to look for on different types of installs....if you need assistance with any of that stuff......happy to trade favors.