My pentair heater was working fine the other day, now when turned on I get the code 128 r13. It is opperated through an Easy Touch board. I start the heater, fan turns on, heating light flashes then goes solid, smell the gas, never ignites, heating light flashes again. It tries this 3 times and turns off, and service heater light comes on. I'm handy, but know nothing about heaters, so I'll need it explained. Thank you in advance