Pentair Mastertemp 400 Electrical Issues
- Thread starter R.Towner
- Start date
If the fuse is blowing immediately, that indicates a short in the circuit.
Pull the board to check for obvious damage.
With the board removed, measure the resistance between the pins marked with red dots.
Pull the board to check for obvious damage.
With the board removed, measure the resistance between the pins marked with red dots.
The only thing I can think of is a bad board.
I would pull the board and check it for any signs of obvious damage.
I would pull the board and check it for any signs of obvious damage.
- May 23, 2015
- 24,464
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Thank you for all of your help James. The board looks clean to me, nothing obvious.
Can't find a damaged wire anywhere. Amazon has a new board for $100 maybe its worth trying and if it doesn't work I can just send it back
Pentair Mastertemp 250 24 VAC short keeps blowing fuse
Hello! This is my first post ever but I’ve been searching and reading the forum for a while about all sorts of issues with my pool. I use TFP app to track and balance my pool chemistry and I love it. However, I’ve been having a problem with my heater. It’s a natural gas Pentair Mastertemp 250...
www.troublefreepool.com
One last thing that i noticed, the red light on the fenwal comes on for a split second before the fuse blows.
Looks like a short to ground.
Try to track down the ground fault by disconnecting everything one wire harness or wire at a time until you find the ground fault.
Label everything to be able to reconnect it properly.
Try to track down the ground fault by disconnecting everything one wire harness or wire at a time until you find the ground fault.
Label everything to be able to reconnect it properly.
So unplug a harness and then recheck continuity at the fireman's switch? Sorry, I really have no experience with this. What am i looking for when it's the right wire? And thank you again, I can't believe how kind you are. Not sure if you could tell but we are strapped for cash (buying a used heater, looking at cheap Chinese control boards!)
Basically disconnect things until the resistance goes from 0 to O.L, which means Open Line.
You want to track down exactly what is grounding out.
You want to track down exactly what is grounding out.
Unplugged and replugged every wire in that thing. The only 2 wires that changed the continuity were the pins on the control board that you had me check and the harness to the left of that 
With the J7 harness disconnected, check each pin to ground and each wire to ground.