Looks to me like a standard 1/4 2 way solenoid to me. 9watt coil by the looks.
You could swap it with the fill solenoid as it may be the same. Or swap the coil from the top just by undoing the nut.
Coil should show 9w worth of resistance. So will be quite a lot...ohms law will tell you its 6400 ohms. Use multimeter and compare it to another 9w coil in the machine.
An electrician will check there is 240v to the coil and that it is switching at the board. But it will be 240v so caution!
Why its steaming from the grouphead..not sure. Maybe the 3way is leaking too. The 3way should stay shut and the steam 2way should open.
My hot water 2way is the same as yours, and its valve is stuffed, but the coil is good.
Here is a coffeeparts one that i think is same as yours. You need to check thread sizes as it could be a 1/8 fitting. The boiler elbow will unscrew out of the solenoid.
Mine has a parker on it, but the genuine part is a different solenoid with a physically smaller coil. Shouldnt make much difference if its same wattage.