Hayward Spa Heater

This morning the gas heater on our spa did not come on.  Not the usual “IF” from being wet and trying 3 times to light, but nothing.  Cycled the system and now the display on the front is totally blank and unresponsive.

Don’t know how to tell the models apart, so not sure if I have a H150,200,250, etc…???

So how do I tell which model and where should I start troubleshooting?

Thanks

Rick