Looked everywhere for small leak behind UDC, can't find it?

[ParkIt]

Guess I'm in good company then, there are a couple of you that have pretty much taken the units apart and put them back together over time. The PDF troubleshooting guides have helped a great deal too, Dan has done a great job on that. Like you I've also read what to watch for and while some have had substantial damage, it's kept me on my toes on where to look and what to keep an eye on until I dig into the guts and sort it out for full timing...half of the year. Could be why not much spectacular has happened (tow driver aside) and this isn't a huge deal, it was just baffling.

Now to get my round to it button squared...

 

[brianharrison]

I am checking back on this thread every once and a while to see if the water heater intermittent problem and strange buzzing sound has come back to haunt you......

From reading you describe a manual pilot that goes out? That would be strange, as I thought majority of water heaters are now Direct Spark Ignition (DSI). You also indicated you may not have an electric heater in your water heater, as "you may change it out as you did in another unit". Maybe I am reading your previous posts incorrectly?

My DSI water heater controls (circa 2011) has the red switch on the old style monitoring panel and it stays red when the LP mode is on. But there is a small red dot to the left of it that illuminates in a "lock out" scenario - ie the DSI module does not sense a flame after the ignitiion sequence time outs. When this happens the DSI module emits a high pitched humm, which I believe is the transformer that steps up 12V to near 200V for the spark. If you were in a lock out mode on a DSI water heater, this may be the source of the humm. Switching off then back on, clears the lock-out and re-initiates the LP ignition sequence.

Here is a link to an old (circa 1995?) Suburban Service Manual that I have used in the past to trouble shoot DSI systems. Section V describes the operation in more detail. It is on my Google Drive.

Brian

 

[ParkIt]

Your link isn't working (google just changed settings so it doesn't always share) but that aside there is only one light which is the rocker switch that stays red meaning its heating the water in the tank. There are no other lights, small round like on the monitor panel or otherwise. The way I know is by hearing the propane kicking on periodically to keep it warm.
Once it was fully dry, ignition worked again though not sure if that is from slight water splash which was happening from the leaking being so high up on the back of the UDC though I want to change it from the ceramic ignition to the DSI panel since that is what held up best in my RV.

Thanks for the input and suggestions, there is always more to learn for each component on these units

 

[pegmikef]

In all three of the heartlands I have had, the little LED light only comes on when you turn the HWH on gas and then it only stays on a few seconds until ignition is achieved. If it stays on then there is a problem with the gas supply. Once started, it does not come on every time the propane kicks in.

 

[danemayer]

Re: Looked everywhere for small leak behind UDC, found it! (easy to miss)

I'm wondering if maybe you have an Atwood water heater.


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