On this Lochinvar boiler, it will not ignite. I first verify I have spark. Next I verify the gas valve is plugged in. Afterwords I connect magnahelic /manometer to the gas valve. This Boiler operates with negative gas pressure. I watch the boiler operate, looking for the negative pressure to rise to about 0”w.c when gas valve opens. Pressure and ever rises, therefore I checked voltage to the gas valve. I have proper voltage at my gas valve and it doesn’t open. Therefore I have to return with a new gas valve.