Just in case anyone else has the same problem I thought I would post it so others may benefit.
My machine would build pressure but not heat. I realised that it would heat for a while, the the pressure would spike and the thermostat would turn off.
I also relized that water would run through steam wands even if machine was off but steam wands opened.
I rang Boema (very helpful) and they said there was a problem with the 2 way solenoid, blocked or dirty. I took it apart by prising off split pin and un-screwing for screws. the solenoid plunger was brown and stuck. I removed it and removed brown build up - possible iron from water - with fine sandpaper and fine steel wool.
Re-assembled and works like new. Saved myself $70 on a new 2-way solenoid plus labour if someone else did it.
Time 30 minutes