Is there any truth in this or have my past problems, involving Wickes waste products, been due to the simple fact that Wickes' push-fit and compression fit systems use a smaller diameter pipe than other 1 1/2" and 1 1/4" products, meant for solvent joins? And, if so, is Wickes the only place where you can buy a coupling to join the differing gauges? Plumbers merchants are always stymied when I describe the problem, yet you'd think they must hear it often!
Adding to my confusion, neither of the 2 types of boss inserts/ adaptors I bought today would fit into the boss on the in-situ branch T! Even though the merchant said it would definately be one of them, they both had the same OD as that of the boss housing on the T! Is this a Wickes oddity or am I missing the obvious?
I'd like to get this cleared up once and for all, as it always presents me with a problem, each time I encounter it!