How does the bypass on the H400 work - Hayward H-series Electronic Gas Pool Heater H400

sounds like it doesn't have any water in the boiler

You have to use some of the special connections on the back to connect the Satellite box. It will not work with those you are trying. See the manual below:

Toshiba SD H400 TU Installation Manual Using Your Sd h400 With Cable Or...

BO code is bypass operation. It means that it is set to operate with an external controller. Things like Aqualink, Aqualogic, Intellitouch, EZ-Touch are all types of automation / external controllers. They have their own temperature sensor and allow remote control operation. To truly find the nature of your issue. I'd start by taking it out of bypass operation and see if the unit fires by itself ( without automation hooked up to it ). The fault may lie with the automation system. You never know.

to start with the basics, make sure there is enough water flowing through the system to activate the heater. you can put sand filter in whirlpool or bypass mode. if there is enough flow through the system, make sure the heater isnt on bypass. make sure that the gas supply is turned on at the heater AND at the meter. if your heater has a pilot light, make sure it is lit.
if you still have issues, you will have to get a service company in

there is no error code 60 in the world of hayward. is there any chance you are seeing bO? if so, that stands for bypass on and the heater is being controlled by a remote controller.

This error means "Bypass Operation". On the back of the control module there are some "dip switches". They have an on or off position. Check switch number 2. Make sure it is in the "off" position. The "on" position is for a remote thermostat.

Same thing happened to mine a couple of years ago. Had to get a new hard drive... works like a champ after a new drive. Got a lot larger one from weeknees.com Great price and installed in no time.

It is likely the keypad that has gone bad. Not difficult to replace. But you want to be sure thats what it is, as it is an electronic part, that is usually not returnable. The part number would depend on the model of the heater. Likely it is a h400idxl2 heater.