First male sure all the gas valves are open. (supply line, heater, etc.) Make sure gas pressure is correct. Check the pilot orifice to ensure it is not clogged. Check for 24 VAC at gas valve from the PC board. If voltage is present at the gas valve terminals, I would say a bad valve. No voltage, bad PC board. I would check the first items initially.
Answers & Comments
First male sure all the gas valves are open. (supply line, heater, etc.) Make sure gas pressure is correct. Check the pilot orifice to ensure it is not clogged. Check for 24 VAC at gas valve from the PC board. If voltage is present at the gas valve terminals, I would say a bad valve. No voltage, bad PC board. I would check the first items initially.