231 Pa. Code § r. 1705 app. A
The defendant may file any applicable preliminary objections either to the class action allegations or to the underlying merits of the class action claims or to both. As stated above, he may not use preliminary objections to raise issues of fact with respect to the class action allegations. All objections must be raised at the same time or they will be considered waived, except, of course, objections to the complaint which under Rule 1032 are not waived, namely, the defense of failure to state a claim upon which relief can be granted and the defense of failure to join an indispensable party.
In class actions in equity, the defenses of laches and failure to exercise or exhaust a statutory remedy, and the existence of full, complete and adequate non-statutory remedy at law, are available as preliminary objections. See Rule 1509; Lilian v. Commonwealth of Pennsylvania, 467 Pa. 15, 354 A.2d 250 (1976) (adequate statutory administrative procedure).
231 Pa. Code app A r. 1705