I just started on a project to remove my 33 year old RayPak and install a new Pentair Max E therm 400HD. Once I got the new concrete equipment bases in an leveled leveled I started placing the equipment. When I got to the Max E therm I got it placed on the bases and the thing wobbles like a toilet on an uneven floor. I will indeed use toilet shims to get this thing stable unless someone else has had the same problem and a better- more elegant solution. Glad I have 3 more days to get this buttoned up.