Relay help

Other Hardware Motors, Mechanics, Power and CNC
1

Hi,

Trying to control a home boiler with an arduino.

Using 5v relay that supplies 250v 10A
the boiler is on a 6A circuit to the breaker.

The relays are closing making a connection and immediately open again. Has anyone have an idea why this might be.

Relays are retrieving power from the 'duino.

Is fly back circuitry required for this

The relay has to turn in a pump fan and then an ignition spark

2

Has anyone have an idea why this might be.

Yes

Relays are retrieving power from the 'duino.

An arduino output pin can not provide the current to switch a relay that is capable of controlling contacts rated at 240V @ 10A. You need to use a transistor to control the relay.

3

Grumpy_Mike:
You need to use a transistor to control the relay.

Along these lines.