Home > Start Repair: > 7 - Control Box
Step Seven: Your Control Box
The "control box" refers to the brains of a hot tub. Normally located directly below the topside control or nearby. Some call it the command center.

The control box houses the pcboard, transformer, incoming power terminal, and component terminals (sockets) that the pump and other components plug into.

Rarely do you need to replace the complete control system box although some only sell the box complete and you can't replace internals to the box.

Most commonly you replace the pcboard or transformer or terminal or component socket only.

Rarely are pcboards built to only apply to one specific application. The board manufacturers have a special onboard configuration that tells the board what you have. Be VERY cautious thinking "it looks the same" mentality. Almost all suppliers will NOT take back a pcboard except under warranty and you get the same board back.

Being an electronic pcboards are more prone to voltage surges, brownouts, blackouts, and lightning. If you have to replace a board more often then 5 years consider getting a surge protector for the hot tub and maybe the whole house. All these types of voltage issues can damage, confuse, or destroy today's pcboard. I have been at homes that needed the pcboard, topside, heater, and pump replaced because of a lightning bolt. Its not typical but lightning can do a lot of damage. That is why if you have a surge in the house make sure the hot tub control system is working correctly.

Most boards have "jumpers" that require telling the board what to do. Jumpers can tell the board you have 1 or 2 boards. Or if you have a circulation pump. So keep the old board and match to the new. Newer boards also can be programmed by the topside control for filter times and various other issues.

How to service:
Pcboards were designed to both make life easier for the homeowner and to make repairs easier. Often the digital topside points exactly to the failure via error codes.

When the failure is the board itself typically you replace the board.

First look at the board. If you see browned or blacken areas you will need to replace the board. If the board looks perfect and was operating fine before, the only issue you can really address is transformer that powers the board. You will have a transformer that either takes 115vac and drops it down to 12-15vac OR 230vac and drops it down to 1-12vac. Most boards operate on 12-15vac so you the transformer takes incoming power and lowers it to the power it needs.

That so you can check the transformer. See Here If you have proper voltage to the transformer and to the board and the board is not operating, then replace the board. If you don't have the proper volt going into the transformer, see your incoming power to the spa. If you don't have proper voltage coming out of the transformer replace transformer.