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Rinnai R85e blew fuses and is now dead
We returned home yesterday from a weekend trip to find one of my Rinnai R85e water heaters not working. The control pad was dead so I took the front cover off of the unit and found both 3 amp fuses had blown. I replaced both fuses ( I did check continuity on the new fuses) and the unit still does nothing. It did not blow the new fuses. I checked to make sure it has correct incoming ac voltage and it does. I though maybe the control pad had gone out as well so i replaced it with a new spare I had but still nothing. Maybe the PCB has died? Any help would be greatly appreciated.
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Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Bob
Vaporstat with a 12oz cut-out and 4oz cut-in
3PSI gauge
Did you ohm the transformer out? Did you ohm out what the transformer drives?
I just don't want to see you put a new transformer in and see it go up in smoke if you can avoid it.
https://rinnai.us/customer-care/manuals-literature
not a lot on wiring or troubleshooting, geez
I rec'd them highly especially since electricity isn't a very good product anyway, everything lasts longer, especially light bulbs.
http://www.thisoldhouse.com/toh/article/0,,387874,00.html
They are very easy to install or have an electrician do it if you are not comfortable around the main box, safety #1.
Bob
Vaporstat with a 12oz cut-out and 4oz cut-in
3PSI gauge
Just one.
I am not a "licensed dealer" for any of the above; tech support must have deemed me competent over the phone with our conversation.
Slow typer.....had to check spelling on Fujetsou.
When you ask him to grab a manometer and he says "a what?" you know he's not capable.
We've talked people through troubleshooting antique refrigerators with damaged float valves via nothing more than text. It's fairly easy to tell when someone isn't capable of something.
That's my opinion on it anyway.
Also, I had to go do a warranty call on one a few years ago and they paid my bill for labor, which totally shocked me because nobody pays labor. Top notch company in my opinion.
So, that is my plug for Rinnai.
Rick
Yours, Larry
I also have an R85 with a bad transformer, which also blew both fuses. The secondary winding is open (infinite resistance). I'm searching for a replacement transformer now. In case my issue turns out the be the same as yours, can you tell me where you found a replacement control board for order?
> It has been narrowed down to the circuit board. I will order a new one Monday. Thanks for all your help guys.
>
> Hi StevenS, I hope you're still around two years later to see this.
>
> I also have an R85 with a bad transformer, which also blew both fuses. The secondary winding is open (infinite resistance). I'm searching for a replacement transformer now. In case my issue turns out the be the same as yours, can you tell me where you found a replacement control board for order?
I don't know anything about Rinnai but I would question why the secondary is open. Did something cause that? It's rare for a winding to just open on its own.
The Rinnai diagnostic manual says to replace the transformer if it's found to be faulty. So that will be step #1
In the time since my initial post, I found a source for a replacement control board. If it turns out the new transformer doesn't solve the issue, I'll give that a try.
Update: My bad. It's the primary winding that's open, not the secondary. I checked impedance where the secondary feeds to control board anyway. It started ~14Mohm and steadily dropped (I assume from a cap charging). So I think that's okay. Or at least not the cause of the bad transformer.
Maybe 60hz vibration eventually caused a winding to rub through the shellac coating causing a short, which in turn blew an internal protection mechanism inside the transformer?
> Installed a new transformer. The 3 amp fuses blow immediately. The solenoids and igniter pass impedance tests. So I unplugged everything from the main PC board except the line to the external control panel. It still blows the fuses immediately. I can't check the individual components on the main board because it's potted. So I've ordered a replacement board.
Sounds like you did what you could.
Potted boards suck for that reason.