switching solenoid noise spikes

[engineer1000]

I am switching an AC 230V solendoid on and off using a relAy to drain a tank of water. The problem is when the solenoid turns off I get a large spikes on the output of by 7805 reg. The nuetral is permanently connected to the solenoid with the relay contact switching the Live .
Anyone got any ideas of how to suppriss the noise spikes?

 

[barry]

If the relay is DC, you need to have a flyback diode across the coil. If the noise is from the solenoid, put a snubber across the relay contacts.

 

[engineer1000]

If the relay is DC, you need to have a flyback diode across the coil. If the noise is from the solenoid, put a snubber across the relay contacts.

The solendoid is a 230V ac one