Want to control 220v water heater but no common wire

[randy]

Actually, I might be operating on a wrong assumption. Is the neutral required for Insteon messaging and control?

I have not used Insteon, but it is a dual mesh system. It combines power line and RF transmissions. The power line component is 131.65khz on one of the high legs. Some systems can employ phase bridging to get the carrier on both legs. In the absence of power line communication, an Insteon device will use RF as a backup - in the absence of RF the device will use power line communication. I would imagine that the communication would work fine without a neutral, but that would depend on how the phase coupler works or if one is used as well as the RF environment. My understanding is that Insteon power line communication is much more robust than X10, so it should work just fine.

[logbuilder]

Most of my Insteon devices are around 10 years old and don't have the radio feature which was added later. The 4030A devices that I have do not have the radio network. I have added a few newer switches which have the dual band feature. I used to need phase couplers but since installing the dual band devices I find that they are no longer needed. The comm stats did improve after installing the newer switches.

[logbuilder]

I'm happy to report that the 4030 is working well controlling the water heater.

On the input from the main box it has two 10g 120v legs and a ground. The hot water heater has two 10g 120v legs and a ground screw.

I connected the input L1 and L2 to the 4030. Then the water heater L1 to the 4030 L1 NC on the 4030 and the L2 to the L2 NC. I then connected the ground wire to one of the neutrals on the 4030.

The 4030 output legs can be either Normally Open (NC) or Normally Closed (NC). I wanted NC.

The 4030 light was on when the circuit was brought back online. Good.
Then I metered the input legs on the 4030. Both at about 126v. Good.
Then metered the output legs on the 4030. Both at about 125V. Good.
The output legs were expected to be ON since I used the NC terminals.
Then went to the plugin and added the 4030 device. Worked first time.
Reset the comm stats on all devices and ran a comm test on all. Heater looks OK.
Changed the status graphics. (OFF now says ON)
Turned the 4030 off via the web interface.
Metered the output legs and they are now @ 0v. Good.

The added the water heater to my HSTouch app so I can see status and turn it off and on. Got to think a bit more before adding events based on overall house status (ie. OFF when AWAY).

I'm a happy camper and will use the other 4030 I have for my water well pump. I expect it to work the same.