The installation guide says that the heater unit needs to be bonded. there is the copper wire and the place to hook it up to the heater. but what dose bonding mean? Grounded?

1) It is safe, but not code.
The timer uses such a tiny amount of power that the installation is safe, and the line is still protected by circuit breaker.
http://waterheatertimer.org/How-to-wire-timers.html
http://waterheatertimer.org/Troubleshoot-household-electricity.html
http://waterheatertimer.org/See-inside-main-breaker-box.html

2) In the main breaker box, the neutral wires and ground wires are bonded together and both connect to ground wire leading out to pole and down into the ground.

3) By code a ground wire cannot be used as a neutral, even though both are connected together in the main box.
This is so electrician can work on ground wires while ASSUMING they do not complete a circuit.
NO ELECTRICIAN should assume that, since the purpose of ground wires is to ground stray current.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

A Better question is what is the voltage? 110 VAC or 220 VAC ... what were you running and what is the new pump. B W G would 'typically' be 110 VAC but could be 220. You must know the voltage you have and the voltage the motor is expecting before you hook anything up ... oh yes, one more wire - dont forget to bond the new motor to everything else, use #6 bare copper for the bond.

First of all you need to have two grounding rods outside the house. Usually they're 12' long and have to be driven in 11-11.5 feet... but different particulars apply to different states and local codes. Ground rods should be placed no less than 6' away from each other and as closely placed as possible to the equipment or structure they are intended to protect.
wrap the stripped 14 AWG wire tightly around the copper ground rod. Try to get it as flush against the rod as if possible so that when you heat the rod later, it bonds very strongly at all points. Then heat the copper rod, rather than the wire and allow the wire to be heated by the rod. Don't heat wires directly or instant oxidation will occur, making it much more difficult to solder. Leave the ground rod to cool off for about an hour.
You would then dig the area to place the rods. The wires running off of them need to be ran to the circuit breaker box and terminated to the grounding bar. If there isn't a grounding bar in the box (only neutral) you can buy a single grounding bar specific to your box to install.

Hi,
The unit will not owrk unless you have 240V ACROSS the black and white wires...if you do not have that coming to the unit then you have a bad breaker...

heatman101

Hi. Ok, with the rear terminal block cover open, you will see three wires. Black on one end, white in the middle and red on the other end. Use your 3/8′ nut driver to remove the nuts or a Phillips screwdriver to remove the bolts (depending on your dryer) and remove each dryer cord wire from the terminal block. When you remove the nuts or bolts, be careful not to drop them down into your dryer. Next, you need to disconnect the bonding jumper on your dryer. The bonding jumper is either a metallic strap (typically copper or copper clad) or a green wire that is connected between your dryer’s neutral (white wire) terminal and the green ground screw connected to your dryer’s frame. If you removed a ground wire instead of a bonding strap from the neutral terminal, you need to connect this ground wire to your dryer’s frame. Loosen the screws at the connector and pull the cord out. Now thread your new cord through the connector and tighten down. This only needs to be snug do not over tighten. Sometimes the old connector will work with the new cord and sometimes not. If not, your new cord will include a connector that you may use. Now,to hook up your new 4-wire dryer cord, connect each wire to the dryer’s terminal block matching color for color (white to white, black to black and red to red). Connect the green wire to the green ground screw on your dryer’s frame. Once the wires are connected, simply recover the space, and secure the cove with the screw provided.

The # 8 wire is a bonding wire for the hot tub or jacuzzi. It is to interconnect all the metal parts and equipment associated with the unit, pump, pipes, handrails, and also now there is a bushing that goes in the piping run to bond the water itself .
This wire will be incdentally connected to the electrical ground when it is bonded to the motor body.

The following link explains how to correctly install a 220VAC appliance cord:

http://www.fixya.com/support/r3575913-installing_a_220_vac_appliance_cord

Match the corresponding colors at the terminal block, making sure the Neutral (White) and Ground (Green or Bare Copper) wires are NOT terminated together.

If you have any questions, please post back and let me know. I hope this helps you.

The black and white wires should both go to the breaker. Not just the black wire. If you hook only the black wire to the breaker then you are only feeding the unit with 110 instead of 220. Both wires need to be hot.

The white is the common neutral, it is probably a 3 wire unit, and you are missing the ground wire. Check inside the control panel and see if someone wired it using the white wire for the ground, it will be screwed into a terminal lug. Check the schematics to see if the unit requires a common neutral to run the controls.