Yea twas expanding foam. The customer said originally there was just large rectangular grille on before and when they've come to install the fan, they just filled it with foam and sat it in. Couldn't believe it when i eventually ripped it off, took some doing
Im sitting mine next month, just getting stuck into gn3, exam success and brian scaddens inspect, test and certification. Not looking forward to it, even less to the long wait for results :(
Had a customer wanting a c/u change, come to have a look at the mains and cant see an incoming earth, theres what i presume to be the remains of an earth clip on the incomer, also no bonding to gas or water. Is the best option to get her to phone up the supplier and ask for a pme installing...