I have an electronic ignition Hayward H350 gas heater and I'm having trouble for the first time this spring.
When I turn it on, the heater tries to light (I hear the ticking from the ignition) but no dice. After a while, I get the "IF" failure code. The gas is turned on and the first thing I did was remove all the gas ports and blow them out. 2 of them were blocked by spider webs. Re-installed and there is no improvement.
Also, I'm not sure if this is related but the Mode button seems to do nothing. I press it and it does not cause the heater to go into spa or pool mode. It stays with the Standby light on at all times. I'm pretty sure this was the case last year too and the heater still worked.