Need X10 signal reliability? Some thoughts.

x10logo_blue_72Since 2001, I’ve tried countless ways to improve my X10 reliability and signal. In this post I’ll give you a little of my journey to full X10 obsession. I’ll also detail what I have found to avoid, what I found to work somewhat, and what I have found to work reliably. As with most anything electronics related, you get what you pay for, in terms of quality and usefulness. If you want, you can jump to my TLDR; Big 3 Conclusion.

X10 – My Journey : )

house-decorated-for-xmasMy wife and I share an affinity for Christmas decorations, so when we built our home we were so excited to decorate for Christmas. I could not wait to put up some outdoor lights and decorations. Here is a picture of our first Christmas in our home. When we bought the decorations, I picked up a bunch of dial timers to “automate” the lights to come on. Each window had a candle, so I got a dial timer for each window (or set of windows if practical). Man did that suck! Running around trying to get all the dial timers to turn on somewhat near the same time. Even when you get them nearly the same, in a few days they were many minutes apart. I didn’t care for that, the retentive part of me wanted synchronization! I had worked many years in a hardware store growing up, they decorated for Christmas with extensive window displays and animatronics, the whole nine yards! They used breaker box dial timers to turn stuff on and off. This was my first inclination, but I would need to install a sub-panel(s), run Romex to all my windows, install new outlets, and run extra outlets outside as well. This method would also not satisfy my desire to dim the lights. I wanted my window candles to progressively dim as it got darker outside. I needed automation, not timers!

X10 Problem 1 – Phase Coupling?


When I bought my first X10 controller (CM11A) and modules (LM465’s) I thought this is going to be great! When I installed my modules and fired up the X10 Home Control software, then Problem 1 became clearly evident – Phase Coupling. I currently work as a Training Specialist for Atlantic City Electric, the electric utility for South Jersey. At the time of my first X10 purchase I worked as a Power System Controller for Atlantic City Electric. (In a nut shell, I controlled the bulk electric system; power flow and voltage control). I immediately knew that one phase in my home was not getting signal.

capacitorTypical US homes have two 120 volt phases, providing 120/240 volt service. Without a device to “couple” the X10 signal, it has to “couple” through your home’s pole/pad service transformer – horrible results! I used a capacitor to “bridge” my phases. I installed a 0.1 microfarad (0.1F), 600VDC capacitor across two phases in my breaker panel. DO NOT ATTEMPT THIS, AGAINST CODE, UNSAFE!!! This worked well, but did nothing to increase reliability.

xpcrI later found X10’s XPCR coupler repeater, which I too installed in my breaker panel. DO NOT ATTEMPT THIS, AGAINST CODE, requires a separate panel. This “worked” for many years for me, but it isn’t the best option now.

The XPCR does two things well:

  1. Couples the phases
  2. Repeats the signal multiple times to increase reliability

The XPCR does other things poorly:

  1. Life longevity is short, I had 2 in 6 years
  2. Creates signal clashing when repeating extended X10 signals
  3. Signal delays and bright/dim issues
  4. Does not increase the X10 signal strength well

SignalincI now use an Insteon SignaLinc 2406H to couple my phases. It is installed in a sub panel with it’s own dedicated 220 volt breaker. It’s only job is to couple my phases and it does it well. I have enjoyed greater phase reliability with this unit, and it does not create any signal clashing. I highly recommend this device for increased X10 reliability, along with the other devices detailed below. Yes, keep reading…I know, I know TLDR; you can jump to my TLDR; Big 3 Conclusion.

X10 Problem 2 – Signal Suckers!

suckerWhen I first started using X10, I found there were certain electronics that if I unplugged, my X10 reliability increased. My computer and home stereo were the largest X10 Signal Sucking offenders at the time. They use power line conditioning to remove “noise”, so that the device enjoys “clean” power. Most decent home stereos still use this technique, you’ll know when the stereo is heavy, it has a good power transformer with power conditioning. Newer home owner level PC’s no longer use quality power transformers, so they typically do not Signal Suck. Plasma and LCD TVs are also huge Signal Sucking offenders. I found the newer LED and OLED TVs don’t seem to Signal Suck as much. I also found that (when running) microwaves, dryers and washing machines degrade my X10 signal. My cheap wireless home printer is also a Signal Sucker. Do you have a Signal Sucker in your home? How do you find out? Unplug your electronics! It’s that easy, unplug all devices and methodically plug them in one at a time, repeating X10 signal testing each time.

x10filterWhen I identified my Signal Suckers, the first device I tried was X10’s XPPF plug in noise filter. DO NOT USE THEM!!! If you have them in your home go remove them NOW, I’ll wait…they are proven fire hazards. I had one melt off the wall with an LCD TV plugged into it. I immediately removed all my XPPF plug in noise filters and read online that this was a common issue with them.

filterlincSo what should you use to stop the Signal Suckers you ask? I recommend and use the Smarthome 1626-10 FilterLinc. I have one on every TV, my home theater and my cheap wireless Epson printer. It plugs into one outlet and provides 2 outlets. One outlet is filtered, stopping the Signal Sucker from offending. One outlet is pass through, convientent to plug in electronics that don’t require filtering. These are great for increased X10 signal reliability, along with the other devices I recommend above and below. You still reading!?? Yes it’s a long post, but it’s well worth the read, but you can jump to my TLDR; Big 3 Conclusion if you’re starting to nod off!

X10 Problem 3 – Signal can’t get there from here!

blockWe’ve covered Phase Coupling and Signal Suckers, now how do I get my CM11A’s 2.5 volt signal to all my devices, out to my garage, shed, outbuilding, etc? The CM11A works good on smaller homes and small X10 installations. It lacks the power to drive a large home’s X10 system that includes many X10 modules and devices. My X10 system hits 50+ devices come Christmas, I had problems getting a strong signal to all those devices.

I found the solution with the Smarthome 4827 BoosterLinc. It “blasts” X10 signals out at 10 volts, more than enough power to reach every one of my X10 modules.

A few recommendations:

  • BoosterLinc works best when installed in a location where the signals are weak but not totally gone. If a Smarthome Design receiver won’t respond to the signals in a certain outlet, BoosterLinc won’t be able to detect the signals either.
  • For homes with widespread signal strength problems, plug the BoosterLinc into the outlet closest to the electrical panel. When combined with a passive phase coupler, the two units will effectively become the equal of a coupler-repeater (sometimes called an amplifier) without the delays and bright/dim issues.
  • Plug BoosterLinc into an outlet without other PLC transmitters, computers, or televisions. When two transmitters, are plugged into the same outlet, the signal strength sent from each unit can be reduced by up to 40%.
  • Plugging a PLC transmitter directly into BoosterLinc will not (in most cases) significantly increase the transmitter’s signal strength.
  • Every home is different, so a little trial and error in the placement of the BoosterLinc is required to determine the best location in your home.

X10 – TLDR; Big 3 Conclusion:

To sum it all up, here are my Big 3 recommendations to increase your X10 signal reliability:

  1. Phase Coupling: use the Insteon SignaLinc 2406H
  2. Signal Suckers: use the Smarthome 1626-10 FilterLinc
  3. Signal Strength: use the Smarthome 4827 BoosterLinc

My 2015 Christmas display:

Thoughts or Questions

Do you have thoughts or questions about this topic? Please feel free to comment below!

18 thoughts on “Need X10 signal reliability? Some thoughts.

  1. Hi Corey!
    Great write up on this…and I actually understand almost everything you said/recommended. As I mentioned on your Amazon Echo blog, I currently have the X10 XPCR mounted in my circuit panel (on its own breakers) and “I think” it is working ok. I at least know that it increased my reliability, but now I see some of the other problems it may be creating at the same time, so I will have to look into the SmartHome devices you listed above. My only limitation will be cost (especially if I have to buy a ton of the filters).

    Also, your Christmas lights look great!! I am sure your kids love putting the lights up with you and making new designs each year. My kids are getting to that age too now, so they are asking about the lights every day and they can actually help when it comes time to put them out on the lawn.


    1. Hey Steve,
      The process to improve my X10 reliability didn’t happen overnight. I too was looking to spend as little as possible, which is why I still use my X10 equipment. I found better and better devices to help. Since you already have an XPCR installed, your next best purchase would be filters to stop any electronics that are sucking signal. Start with just the most offensive device, there may be a large return on filtering just one electronic device. The FilterLincs are moderately priced, eBay and Amazon to find the best pricing. Changing out your XPCR will probably require the SignaLinc and the BoosterLinc for your needs. The SignaLinc is relatively inexpensive, but I’ve found the BoosterLinc the most expensive. Best of luck with the reliability improvements.

      Enjoy those kids and their excitement for Christmas, they grow up so fast, mine are 10 and 7 years old now.

  2. Hi Corey,
    Once again Great write up on X10 modules. I also have the xpcr, boosterlinc and a filterlinc which work great but I’m gonna try out the SignaLinc 2406H and remove the xpcr. I’m not really impressed with the design, seems to be made from very cheap plastic, It really didn’t perform well till I bought the boosterlinc and filterlinc. I also have the cheap xpff x10 filters and had one fry the first week of being plugged in, so I think I am going to pick up a couple more filterlincs to replace the remaining xpff. Thanks for the heads up on possible fire hazard with those things and keep up the good work on open source.

  3. Hi Corey,
    Thanks for your helpful comments on X10 signal reliability. You didn’t mention the XTB-IIR amplifier from JV Digital Engineering ( The reliability of my system of approximately 30 X10 devices was substantially improved by this device. I use no other bridges, filters, or amplifiers. The company’s Jeff Volp also provided great customer service.

    1. Jim,

      Thanks for sharing this information. I am aware of JVDE’s high quality products, just never made the leap. I’m gonna have to buy one.

  4. Corey,

    Great article and well written!!

    I just installed a 6 module x10 system in our new one story house and the only problem seems phase coupling. Can you use two transmitter modules to solve this?



    1. Two transmitters may cause a signal clashing. Not to get too technical, the CM11A’s transmit at the zero crossings of the 60Htz AC cycle, they would be transmitting “out of phase” so to speak. Even if you don’t install a phase coupling device, your service transformer is “bridging” the phases. The signal on the other phase is typically to weak the devices don’t receive the signal, which is why a phase coupler is useful. Two controllers could “clash” through the bridging provided by your transformer, and could degrade both phases. For the cost, a phase coupler is equivalent to a controller.

  5. Excellent information. I learned a lot. Can you tell me what type of light bulbs you use in your setup? Are you aware of any LEDs or CFLs that will work correctly with dimming? Thanks!

    1. I exclusively use Cree dimmable LED bulbs – Soft White. I really like that they don’t turn orange or purple at low dim levels., like other brands. I replaced nearly every bulb in my home about 18 months ago, when Home Depot ran a sale on their 1st gen bulbs to make way for the Connected Cree bulbs that were coming out. I got them for about $2-3 bucks a piece for the A19 style., and $4-5 for the PAR20 & 30s.

      You do have to be aware that X10 dimming modules and switches require approx a 40 watt load to properly operate, that’s why I left a few incandescent bulbs in single bulb lamps.

        1. For best X10 module and switch dim/bright results a minimum 40 watts of load is recommended. If using dimmable LED bulbs, one is typically much less than 40 watts. This is one drawback with using more efficient bulbs with X10.

  6. I just facepalmed. I’ve been playing with X-10 for probably 10 years or more now, and I always wondered why the signal only carried to about half of the house. Duh… signal isn’t “jumping” to the next phase. I knew this… duh. I kind of set it aside for a while, but with the Echo, and your other write up, I dug them out of storage (there’s about 20-30 devices just sitting there).

    Any idea if there are distance limitations with X-10? My workshop is about 300 feet from the house, so service comes from the meter, into a disconnect that then wires into the breaker box for the house, and then 300′ of 4-0 direct bury out to the shop.

    One of the first projects I want to complete after setting up the Raspberry Pi is the ability to “All on/all off” the outside lights There’s about six switches scattered about the house, some in odd places like my daughter’s bedroom, so being able to turn them on and off remotely would be a ver good thing, and being able to turn the outside lights on the shop would be a huge bonus too!

    1. Dave,

      It really all depends on the equipment attached to the line(s). I have a signal booster that helps the signal reach my out buildings reliably, but you may not require one. Give it a try and if you find you need it a BoosterLinc would help.

  7. Thought you might have some insights regarding (or at worst get a chuckle from), a puzzling X10 phenomena that I have observed for years at my mother’s home.

    Three or four X10 Lamp Dimmer Wall Plugs connected to incandescent lamps in the family room and an X10 WS467 for the pool light. Using a wall-mounted Leviton controller or PalmPad via RR501 RF for control of IBM Home Director routines loaded into a CM11A module also located in the family room.

    Her 2007 Samsung 40″ LED TV paralyzes the X10 signals in her home when it is turned on (my 2011 Samsung Smart LED TV seems to only interfere with X10 commands from the IR543 controller located on the same outlet). I have tried the SmartLinc and several other highly recommended filters without success on both of these Samsung TVs over the years.

    Here is the mystery: Only at my mom’s house, after the TV is powered on, the first X10 command that is issued will wait (for hours) until the TV is powered off before it executes. For example, with the TV off, pressing the button that executes the routine to turn all lights up works as expected. Turn the TV on. Press the button for the routine that turns the pool light to 1% – nothing happens. Three hours later, turn the TV off, look outside and watch the pool lights fade to off (1%).

    This is repeatable 100% of the time. There is also a halogen floor lamp connected to one of the X10 Lamp Modules that also has the same effect on the X10 system. Turn it off, and an x10 command which was issued unsuccessfully some time earlier will finally execute.

    I have discussed this scenario with several X10 aficionados, including a good friend of hers who is a retired electrical engineer, and none have come up with an explanation of how this can happen.

    Your comments would be of interest.

    1. Hey Joe,

      Yeah X10 reliability woes are for the birds. Every year during the holiday season, my home exhibits different X10 reliability issues due to the change in devices plugged in various locations of my home, number of X10 modules, addition of other home automation devices, different lighting choices (LED vs. incandescent), etc. The worst however is when you know the offending device and can’t do anything about it, as you have indicated. I have only come across one such device in my X10 experience, it was a cheap HP all-in-one printer scanner. The power supply was a big ugly thing and so was its ability to suck the signal right out of my home. I simply replaced the printer since it was so cheap, not so however for a TV. Your mother’s 2007 Samsung TV must have a fairly high level of power conditioning built into the TV to keep the power ‘clean’ for the unit. LED was the up and coming new kid on the block in 2007, competing with Plasma TVs. Most Plasma TVs are also major signal suckers, they are fairly vulnerable to ‘noise’ on the powerline. Halogen lamps by the makeup of how they work, generate powerline ‘noise’ when they are on, this is a known issue for X10 signal interference.

      So I am not fully familiar with the Home Director software, but this is my hunch about the routine stuck in limbo until the TV or Halogen lamp is turned off. Is this routine executed by the IBM Home Director program? If so, then the Home Director software may be waiting for the 75H8381 2-Way Serial Interface to receive a success message back from the module(s) it is trying to control with the routine. The software may continually be sending the command(s) until a success is returned. The software is not getting the success message while the interference is present, but remove the interference and the module(s) get the command and return the success message.

      This could be proven right or wrong by turning on the offending device, issue the command, remove the Home Director controller from the wall, turn off the offending device, see if the command is still being executed.

      Let me know the outcome!


  8. Corey,
    Do you have any thoughts about the phase coupler x10 used to sell?
    It looks like a kidney capacitor, but supposedly it has other elements included in it.

    It is marked phase coupler 630 volts

    1. Never mind.
      I got stuck with a .1 uf 630 volt capacitor photoshopped with a phase coupler label.

      It is now living in the trash

      1. Bummer…Yeah X10’s XPCR coupler/repeater was their best attempt, but even this has issues, which I wrote about in this article.

Leave a Reply

Your email address will not be published. Required fields are marked *