My Quattro gold boiler will start up, both HW and CH. After about 3-5 mins there is a soft clunk noise and the burner stops, green light goes off. Just like when it is up to temperature and no call for heat. Then after about 5-10 seconds the green light comes on, but no ignition, then it locks out. Pressing the ignition lock-out button after 15 secs results in ignition attempt, but no joy. After about 10 mins (when something has cooled down?) it will work again.
Help!!
Help!!