I just wired a new breaker box from the service box and have connected my dryer to it. Now my dryer won't heat. I tested the 220 outlet with a multimeter and between either hot lead and neutral I get a reading of 120v but between both hot leads I get nothing. I'm told that it should read 240. What could be the problem?

What kind of cable are you using?

Are you using a double breaker?

8 or 10 gauge cable and double 40 amp breakers

Well for one very simple thng, if you have an analog meter, your meter may not be set correctly.

However if it is a digital meter, then most likely you do not have to set it.

What is the voltage it is set for

If you are using a double breaker with the hot leads connected to the breaker and the white connected to the neutral you must have incorrectly wired the receptacle. I assume you are checking for voltage through the receptacle. Remove from box and check voltage at the terminals.

You said double 40 amp breakers. Do you mean a double 40 amp breaker.

Wire should be 8/3 (that's 3 conductors and a ground, 4 wires)

I bet this is GE or FPE panel and the breaker is installed wrong. The breaker MUST contact both panel busses. Both these style breakers are capable of being installed incorrectly and only contacting one buss.

Also, change the 40A breaker to a 30A.

It is a GE panel. I'm going to try to upload a photo to see if that will help. How can I tell if the breaker is installed incorrectly? Dryer circuits are on top.

Photo: Breaker Box Dryer is Top 2 circuits

That's not a double breaker. A double breaker is two breakers made into one with a handles tied together.

If you look at the way those two breakers contact the circuit panel, they contact the same leg of the incoming power. Giving you 120 volts.
The way the panel is made, one breaker space contacts one leg and the next space down contacts the other leg. Giving you 240 volts.

Get a 30 amp double breaker. Remove the two 40 breakers. Move all the breakers on the left hand side down one space. Plug in the 30 double in the top two spaces.

Also, your panel is wired wrong.

1) The neutrals and ground MUST be on separate bars in this sub-panel.
2) The existing bar must be used as the neutral bar and remain un-bonded. IOW leave out the green screw that came with the box.
3) Get a new dedicated ground bar and screw it directly to the panel box.

That panel is nice and neat, but the mistakes and violations concern me.

Seems like a pretty aggressive project for a HO who really isn't sure of how a panels buss bars are arranged, and of course the obvious grounding issue. Nevertheless the panel installation was neat and clearly labeled.

hkstroud, thank you! You saved the day. Dryer works perfectly now. These newer panels are much different than the ones I'm used to.

So, now that the dryer works, will you be separating the grounding as suggested?

Neatness means nothing when done wrong.

A photo of the proper circuit breaker would be great help in illustrating to other.