[ChrisAtTech]

I've been trying to diagnose a problem with one circuit at our new house and I'm stumped. Any advise you can offer is greatly appreciated!
Background: A small hot tub and heater were plugged in on the same circuit and the power to that circuit went out as it would with a blown breaker. The breaker did not look blown but I turned it off and back on anyways. Still no power. Thinking maybe the labels were wrong, I flipped the main and all the breakers just to be sure, still no power to that one circuit. Pulled the breaker out and tested for continuity and it was bad (20amp Square D residential, 200amp service). I replaced the breaker with a new one. As soon as I turned it on, it popped. I turned it off and back on again. It stayed on but there was still no power to the circuit. I pulled the new breaker and tested it for continuity and it was blown. So, I pulled all the outlets and looked for burned wires. Everything looks fine, not even a hint of darkened wires.
The only thing I can think of doing next is trying to figure out if there is continuity between the outlets, although I'm not quite sure how to do that. Does anyone have other ideas? Or know what would cause a circuit to immediately blow a breaker like that? (Nothing except maybe a lamp was plugged in to the circuit when I replaced the breaker.)

 

[jmon]

Agree with you. Direct short somewhere. Electricians will be along shortly to give you advice on how to proceed and what to check next.

 

[chandler48]

You apparently have a high amperage draw with the hot tub AND the heater. What wattage heater? Unplug the heater and see what happens with a new breaker. Heaters draw a lot of current, so coupling that with the hot tub heater, you probably are over. Check the receptacle where the heater was plugged in. It is probably scorched and melted a little.

 

[ChrisAtTech]

The heater and hot tub were unplugged when I replaced the breaker. I checked both outlets and there were no signs of scorching.

 

[JBoot]

Just for clarity: You have a 120v plug-in hot tub and you have the hot tub motor and the hot tub heater on the same circuit? Is the wiring copper or aluminum? Is the outlet a GFCI? Was this outlet originally designed for a hot tub? Is this outside or inside? Has this tub been moved recently?

 

[joed]

Sounds like a direct short somewhere that burnt the breaker points off.
You need to use an ohmmeter and track down the short. Don't try another breaker until you find the problem.

 

[ChrisAtTech]

@JBoot: it's a plug and play hot tub on an outdoor outlet, only requires 110V. The hot tub cord has it's own GFCI built in but the outlet is not GFCI. It was moved recently, but it was plugged in for a couple of weeks before the circuit blew. When the circuit blew, an indoor ceramic heater had been plugged in. Wiring is copper

 

[joed]

Two heaters (hot tub and ceramic) on the same circuit would be a problem.
But it does sound like you have a dead short.