Hayward H400 ED2 panel goes out once temp is raised. HELP! POOL PARTY FOR 9 YO WED!

[MarD]

Hi all,
I need help. Heater was working fine a week ago. Heated pool overnight and it was maintaining 76 degrees, I believe it was not heating/ignited at the time and just maintaining the 76 degrees in morning when I raised the temp from 76 to 78 and suddenly the panel went out. After fussing with the circuit breakers and manual temp limiter switch for hours I was able to get the panel to light again. It ignited but then shut down after 5 seconds and gave me error code SF. I purchased a new thermistor and installed and it did not fix the problem. I was told by Hayward to replace the control panel. I did and when I installed, the screen read the correct pool water temp but when I switched from standby to "POOL" the panel blanked out again with no error codes. The control panel screen will now not light up again. Any ideas?

 

[ps0303]

Is the fuse on the back blown?

 

[Davejavu]

It could be a wiring problem. It is not uncommon with outdoor electronics to get corrosion on the connectors. A symptom of corrosion is that the unit will power up, but any with significant current draw (i.e. motors starting up) there is not enough of an electrical connection to maintain the current flow. And then anything that needs electricity can loose power.

With the circuit breaker off, check for corrosion in the wire connectors. I'm not familiar with this unit, but anywhere there is a connector could be a problem (at the control panel, at the power supply, the internal fuse connections, line in connectors from the house power, etc). You can also check the connection to the circuit breaker (in your house/or pool electrical circuit breaker panel) for corrosion. Also make sure any wire lug is tight (screwed down on the wire(s)).

Also if you are familiar with using a multi meter, you can measure the resistance from point to point of any wires. Make sure the reading is near 0 ohms (or at least less than 10 ohms). Higher than 10 ohms indicates corrosion or a wire break. Also, if you or a friend knows some basic electronics, then figure out where all the power supply wires are at and measure the voltage at those points before and after trying to start the unit. If the voltage drops significantly, then that is also a clue.

Finally, use the googles to find videos on how to diagnose and repair electrical connectors.