TOPIC: Electric Testers

Okay first thing I would do is take a reading on both sides of the main disconnect.  This will determine if the problem is before the Service panel or not.

So my question is, what's the voltage readings on both sides of the main disconnect?

Very good,

it is a main lug panel

one leg is 120/120, the other is 120/40

If you have 120V on both legs in the service panel and one leg of a 220 circuit is reading 40V and various outlets are reading 40V...

Everything I can think of would affect current and not voltage.

I'm thinking bad breaker, or bad wires, or bad wiring setup.  Shoot I'm even trying to think if you can cancel out the phase somehow (I'm no electrician but I think a phase problem would cause bigger prob's than 40V reading).

Some where, somehow I guess they are stepping it down to 40V's.

You tell me, I give on this one.  :-\

John,

What about if you disconnected the two hot legs feeding the heater and you now got a reading of 120/120, 120/0 at the main?

Then something is still feeding it!  Did they have the 120V outlets feeding one of the 220V legs?

No, no.

When the wire from the breakers were disconnected, the 40 volts disappeared and instead of being 120/120, 120/40 at the main, it was 120/120, 120/0 at the main.

One of the bus's was bad in the panel itself. The reason for the 40 v when it was tied into the heater was because some current was being backfed into the dead leg.

So, the story ended up, instead of being a bad heater, it was a bad panel. Because it was a main lug panel, the whole panel had to be replaced. But, that is a story for another day... and boy it is a story.