HWH control panel issues often stem from corroded connections or worn switches. Clean connectors first, then consider membrane switch replacement before buying a new $400-800 panel.
Furnace blower runs but no ignition usually indicates sail switch, igniter, or gas valve failure. Check sail switch for debris first. Watch for spark at igniter. First run of season may need multiple cycles to purge air.
Shurflo 4008 pressure switches fail from frequent cycling. Replace the microswitch for under $20 from Amazon. An accumulator tank reduces cycling and extends pump life.