I have a Huebsch top loading washing machine, model LWZ17NWB3069, which takes approximately 45 minutes to fill with water before the wash cycle commences. Is this normal? Also, recently the linen is coming out still dirty. Is there something obvious I am missing?

Forty-five minutes to fill is not normal, it should take four to five minutes. Either the water pressure at the location is poor (under 20 psi), or more likely the filter screens are plugged with debris which could lead to the washibility issue of a dirty water supply. There are two sets of screens, one on the fill hoses and another set inside the water valve.