I have the Hayward H400IDL2 heater as well. Have had it for 4 years and has worked well until now.
The other day I went out to warm the jacuzzi and turned on the heater as usual. Blowers came on. Led Light panel illuminated the temp, I entered the desired temp as usual. Everythings seemed to be working normally. I left to go into the house to allow it to reach the desired temp and returned 5 minutes later.
When I returned there was like there was no power to the heater. No blowers. No led panel lights. By pressing the standbuy/on/off control absolutely nothing happened.
I checked the breakers and nothing as blown. I opened the front and saw the 4 fuses and the two left fuses seem to look dark so I decided to change them. BTW wheredoes one obtaain these fuses for this unit. The 1.5A that I found were two fat, too short or too long. Finally went to an electrical supply firm and found them but dont know if they are the right ones. The fit but still nothing occurs.
I dont know what else to do. Has anyone else had this same problem? What is the fix?