My 15? 20? More? Year old Hayward H150 millivolt heater (I got it used from someone who got it used from someone) wouldn’t light this week. Narrowed it down to (I think) the gas valve. Have in laws and family coming over and no one had one in stock, and it’s, well.....Not exactly the cheapest part in the heater to replace. At what point do you just replace equipment instead of repairing? I made my decision already, just curious about what others would have done