How To Fix The SubDrive75 - Fault Code 5 - They Have A Bad Reputation

This tutorial will help you understand how to fix the SubDrive75 constant pressure controller by Franklin Electric. This well pump pressure controllers have a reputation of burning up after a few years of use. The reason is most likely bad boards that the components are mounted on. All it takes it just a bit too much heat and BOOM! The system burns out and you've got no pressure.
The solution is to take the bad board out and circumvent the burned legs on the board with wire. This fix will require soldering led, a solder iron, and 14 to 18 AWG (gauge) wire.
REMEMBER TO BE SAFE. THE SYSTEM USES TWO 420 VOLT CAPACITORS. For those that don't know capacitors quickly store energy and release it all at once. They will shock the hell out of you so YOU MUST TURN OFF THE POWER AND WAIT 10 MINUTES BEFORE WORKING ON THE HARDWARE.
I REPEAT !!!! YOU MUST POWER OFF THE SUBDRIVE75 AND WAIT 10 MINUTES BEFORE WORKING ON THE SYSTEM

[@SilverSerpent5]

It still works with no issue.

[@derrickdavis2012]

What's funny is I am a well guy and I went out to an out of water service call yesterday. Low and behold it was a subdrive 75 which the homeowner complained about a burning smell prior to me getting there. The mother board on the right was glowing red and burning in a similar spot as yours when there was power to the drive. I was not about to solder wires on the piece of crap and be liable for possibly burning someones house down later. You are correct the price on one of these drives is in the $2000-$3000 range. We replaced the drive with a PID-20 Pentek Intellidrive which is a more dependable unit. It's also a much more user friendly vfd. After installing the new drive we did notice that his pump wouldn't build over 54 psi so them having a weak pump could have caused the subdrive 75 drive to be running non stop. There was also a bunch of drywall dust inside the unit which could have made it hard to keep cool in operation. I am glad your fix got you out of a jam and saved you some cash. Good luck 👍

[@SilverSerpent5]

IT STILL WORKS WITH OUT ISSUE. 10/8/23

[@tenaciousjoe]

Thank you!! This worked! I really appreciate you sharing this video

[@SilverSerpent5]

AWESOME JOE! I knew eventually someone would appreciate this tutorial.

[@LearnPlumbing]

No greater feeling when you reaearch something Learn how to repair it properly and it then works properly. Thank You for posting your video

[@michaelgaudette4934]

Great video, same problem, same fix, and success. Saved me $1,500. Thank you.

[@SilverSerpent5]

Glad it helped

[@j.kevintackitt7272]

Let me say a BIG THANK YOU! & another BIG THANK YOU! for your video. We came home from out of town and no water. I found your video and copied what you had done to the circuit board. My board had similiar upper damage, but not in the same holes. i covered all six circuits and now it is working. God was so good to let me find your video. May the Lord richly bless you and your family. Again THANK YOU VERY MUCH

[@SilverSerpent5]

Fantastic! Best wishes.

[@chrislittle5734]

My unit stopped working yesterday and I thought it was fried. We went without water for 15 hours and had a well company scheduled to come out tomorrow to replace the unit... until I saw this video. I took mine apart and found only one bad connection. Had it soldered in 10 minutes and we were back in business! Thank you!

[@SilverSerpent5]

ROCK ON Chris!

[@lightguy1]

My SubDrive 75 failed today after over 18 years...yea, I realize I was lucky. Most of my neighbors have replaced theirs multiple times. One of the red things between all of those big doughnut shapped things (I know, they are some kind of toroidal inductors or transformers or something) compleatly melted down and fried the board. It looks like it nearly started a fire. I don't think this board is repairable. Any idea what those red things are??? Thanks for the video and for updating the posts to let people know the repair held up.

[@ryanm356]

Thanks for the helpful info. I just fixed mine as well.

[@SilverSerpent5]

Well done. Pun intended.

[@user-mr2gn6mc2p]

Thanks for posting this. Just had this happen this morning with three legs needing to be jumped. Up and running - for now?

[@hypermodeboatsandloaders2500]

Identical problem, check this board first! I ended up replacing my pump after ruling a wiring problem out, then fix it this way easy

[@wally6193]

I was wondering the same about the current draw now compared to when it was installed. What HP of pump are you running on this drive.

[@SilverSerpent5]

3/4 HP Goulds 7GS07422 - sorry for the late response, I don't frequent this YT account very often.

[@austinselectronics6265]

i have a subdrive that has error f9 can you tell me what might be wrong?

[@mgyer2218]

Had no water this morning my problem was the fuse its solder in so for now its hot wired looks like a 45 Amp until I find one it will stay hot wired both my lights were blinking very slow and very dim

[@buckeighty9]

Not sure if you will see this since the video is a year old now, but how long did this fix last for? Or is everything still working?

[@SilverSerpent5]

David, The fix was applied in Jan of 2020 , It's holding up fine it's now Feb 8th 2022.

[@SilverSerpent5]

It's still working fine 5/2/22

[@SilverSerpent5]

Still working with no issue - Three years later.

[@williamwhittaker5447]

Mine keeps saying f15 ..not sure what that code is..can't find it anywhere

[@freedumreckkords]

Tried this. It did not work for me. Still getting the fault code 5

[@wally6193]

I'd say it's simply a poor board design by Franklin, they under rated the board traces for the current required. Someone didn't do their prelim design work correctly to make sure they had heavy enough traces. I hope Franklin has redesigned that board to fix the problem.

[@SilverSerpent5]

Many people bitch about this issue. I'm sure they fixed. it. My board still works perfectly after the fix.

[@wally6193]

just a note to everyone on this board. Use a proper solder sucker and resolder each connection properly. Actually I would add(and solder) some bare 14awg along each trace from point to point which means you'll have to clean off the coating on each trace and solder the length of each piece of the added 14awg. This will give the trace a higher current capacity which should fix the problems going forward so it doesn't repeat the failure. What has happened is the original solder joints become what is called a cold solder joint due to the repeated heating and cooling of the joint by the high current flowing through the connection. Over time it is bound to fail. Again it's a poor design by Franklin or who ever designed their boards.

[@SilverSerpent5]

Wally, you make good points. Just an FYI: It's been over two years and the thing still works fine.

[@LearnPlumbing]

Thank You for the update. Good feedback

[@josealemany4525]

These control boxes are junk especially at the price! Mine kept burning the terminal strip where the pump wires go. High humidity location (Mexico) the wires arc and burn the bakelite to make a permanent carbon short. I was able to stop the arcing by coating the terminals with dielectric grease. Poor engineering!

[@SilverSerpent5]

YEP!