Kitchen base units off plumb - help please!

[steve4surrey]

Hi, after spending some time levelling new kitchen base units to the same height and all level L-R and F-B, the sides are a little off plumb (spirit level and frame square confirm). What am I doing wrong here as it’s driving me potty? Howdens units with 4 adjustable legs.
Your help would be much appreciated.
Thanks
Steve

 

[oldbutnotdead]

Have you checked the units are actually rectangular rather than trapezoid? (Measure diagonals from opposite corners, bottom left-top right should equal bottom tight-top left. If they're not equal you need to square them up

 

[steve4surrey]

Hi, thanks for the advice. I’ve measured one 600mm base unit and that appears to be out by 3.5mm between the 2 diagonals. Next question is how to square up, they are pre assembled units?
Thanks Steve

 

[oldbutnotdead]

Wonder what tolerance Howdens work to- I'd be on the phone to them first off.
After that you need to have a look at how they're built and what keeps them square.

 

[steve4surrey]

Thanks again, I’ll check the rest first and take it from there. Steve