Alewin2

How do I check the ohms. The heater is about 8 years old but I have replaced the circuit board and blower in previous years

I have a Sta-Rite SR400NA heater. The blower comes on but it doesn't light. I checked error lights and the afs light comes and the service heater light comes on. I jumped out the afs and than the afs light does not come on and the service heater also does not come on however it still does not ignite. Please help Thanks, andrew