I replaced the control board and the ignition control module on my Ruud furnace. I have 24 volts at the ignition control and only 8 volts at the gas valve. If a supply 24 volts via a jumper wire to the gas valve the valve opens and the burners ignite.Is it possible that I got a bad control board and is it safe to use a jumper wire to supply the 24 volts for the gas valve?

Remove the 2 wires from the gas valve and check for 24v with a call for heat. If you have 24volts when disconnected from the valve you have a weak transformer or a loose connection on one of your limit switches.