Said It Here

How to know if my heat pump wire is the right size?

Electricians can flag heat pump wiring as undersized and flickering lights can hint at electrical issues, leaving homeowners unsure how to verify the wire size themselves. This makes it difficult to know if an existing wire is correct when handling repairs or dealing with safety inspections.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    resetting the breaker panel when units trip
  2. 2
    Treating the existing connector size as good enough
  3. 3
    Using a spade connector

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/AskMechanics1 person · September 2026

“Broke the wire on the A terminal. Got a new connected but how do I make sure the old wire is the right size?”source ↗

PlentyCommission5771 · r/AskMechanics · 1 upvotes
r/askanelectrician1 person · September 2026

“I recently had an electrical safety inspection and the electrician said the wiring that serves the heat pump is undersized.”source ↗

“I have noticed the lights flickering on occasion, though.”source ↗

ConnectMaintenance2 · r/askanelectrician · 1 upvotes

Where this came up

People with this problem also raised