Our house has a Square D QO style breaker box, where it uses single pole breakers that have 2 clips on them like this:
enter image description here

I am looking to add a new breaker and am out of physical space in the box currently.
The box currently has 4 tandem breakers, so I figured I would just replace a single with a tandem. (Based on info from this thread, physical space is the limitation.) When shopping for a 2-20 tandem breaker, one of the guys helping me at the store told me my box is super old, and I should just upgrade it.

It seems parts for this box might be harder to acquire compared to a new box, but should I legitimately be considering upgrading my box just cause its old?

1 Answer 1


Don't listen to the guy at the store telling you to toss out a perfectly serviceable QO box. Parts for the QO line are available through practically every supply house in North America, and most of the big-box stores too -- it's quite common to this day in both residential and light commercial work, and as far as I know, hasn't been altered in a backwards-incompatible way since its introduction in 1955.

As a general rule -- if the panelboard is of a type still in use today (i.e. QO, Homeline, CH, BR, QP, or THQL), has the ampacity and physical space (incl. tandem/double-stuff slots), and is in good condition inside and out (no hot spots, arcs, or burnt insulation), it's a keeper. It's those pesky FPE, Zinsco, and to a lesser extent Pushmatic panels that need to be sent to the smelter....

  • All my panels are CH and Pushmatic. I'm deliriously happy with the CH panels and would buy more except 3/4" wide breakers limit your options for more exotic breakers. The Pushmatics have got to go. Commented Sep 10, 2016 at 20:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.