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Doorbell Powerflash Frustration

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    Doorbell Powerflash Frustration

    Hey All,

    I've spent all afternoon trying to install a simple doorbell with a powerflash module and its driving me crazy.

    This is new install, not a replacement of an existing doorbell system. The doorbell switch I bought is lighted, and rated for not more than 16VAC. I didn't really want to install a transformer, although I bought one just in case (also 16VAC).

    The powerflash doc only talked about 6-18V DC so I wasn't sure about putting in the 16VAC transformer.

    Anway - I figured heck with the lighted switch for now, I'll at least get the doorbell working (very high WAF - I have a large new-build house and when someone knocks on the door you can't hear them unless you are in a near room).

    I connected it so basically the contacts from the doorbell are wired directly to the powerflash. When I plug the powerflash in, I get an immediate doorbel action (HS log - H1 ON), and then everything goes stupid. If I push the 'all units off' button on the powerflash, I see that in the log. If I push the test button, the log doesn't reflect anything. If I actually push the doorbell, there are no log entries. I've made 20+ trips from the basement to my front door today...... my legs are tired.

    Oh - I'm using the "B" option with mode "3".

    Testing the wiring with an Ohm-meter I have high resistance except when the button is pressed, and then I get contact. That sounds right to me.

    With everything in place, even if I short the contacts on the Powerflash I get no reaction in the log.

    I read in the forums how to connect it using a transformer, but that shouldn't be a requirement, is it? I don't care right now if it is lighted, I just want it to work.

    BTW - I'm only using an HS event for the doorbell sound - I don't have a physical chime or bell to drive.

    Either my powerflash is bad, or I'm totally backward on my understanding of how this works. (The latter is more likely).

    Help! Thanks!

    Steve C.

    Think of the lighting and the button as to separate and distinct things. In my doorbells there are actually 4 wires two for lighting and two for the button contacts.

    If there are three wires then there are other possibilities. A DC source is between two of the wires (call them a and b) and at the button the light is across the same wires. DC is required only if the light requires it such as an LED. The button is between two wires call them b and c, note b is common) and supplies a voltage on c relative to the a wire when the button is pressed.

    You state that if you short the powerflash contacts, it does not register with homeseer. Concentrate on that. That must work in order for the button to work. I use a powerflash to turn on a shop vac system when any switch is thrown in the workshop along the vacuum pipes. All switches in parallel.

    Hope this helps



      I have never worked with the power flash unit, but from a basic testing process, here are a few suggestions.

      Instead of running up and down the stairs, relocate the power flash to an outlet beside your HS box.
      Using a jumper wire, temporarily jumper out the terminals. This is the equivalent of pushing the door bell button at the door. It also saves a lot of walking.

      If memory serves correctly, B3 sounds like the correct mode and that should activate another module on while the button is pressed. You could try setting an appliance module to the same house code/unit code to see if it responds.

      Your comments about the wiring sound correct. While the button is open, you should read an open circuit on your multimeter. If someone pushes the button, then a fairly low resistance should be read.

      Hope this helps.

      Brampton, Ontario


        That light bulb is killing you.

        Because the light bulb is in parallel to the button, the PowerFlash is always seeing the switch closed; It sees the light bulb as 'closed' when the switch is open.

        B3 is the correct setting for your configuration. Let me look for that thread on doorbells with PowerFlash . . .

        Ok, here it is:

        Also, AC is fine with the PowerFlash. However 16vac may be high, since it becomes about 22v peak dc when rectified (internally to the PowerFlash). I would recommend a 12vac transformer.


          Rocco - that's why I'm confused.

          Rocco - I expected that maybe the Powerflash was seeing the contact as constantly closed, because of the parallel light. I get a high level of resistance on the line without the button pushed. But you'd think than when I pushed the button that there would be some change in the log. Hence my confusion.

          I suppose that the powerflash is detecting a contact (because of the light) regardless of whether the button is pushed or not. So pushing it produces "more contact", but that is irrelevent to the Powerflash. Could I add a resistor to the circuit that would make "more contact" into "just enough contact"?

          I had found and read the thread you provided prior to my original post. I suppose if I do it right, with a correct AC transformer per that thread, my problem would go away. I was just hoping I could do something without a transformer as I'm not really concerned about the switch lighting up.

          I'll put a motion detector on the porch so if someone walks up the light will come on and they can see the darned switch.

          I guess that I should not have bought a lighted switch.... but you'd think there'd still be a way to do this.

          Steve C.


            Steve C,
            How are you going to power the door bell without a transformer?


              Can you just go into the switch and take out the light? The way it's wired with the light i think even if you power the light up you may still have problems with the powerflash not sensing a complete open or closed condition.
              XPpro SP3 /w HS Standard, HSTouch Server -, HSTouch Client HSTouch Android -, HSTouch iPhone -
              Playing with HS3 a bit but it's just play at this point.


                The cheapest and easiest solution has got to be to buy an unlighted switch.


                  Im using a power flash with lighted doorbell switch. I had same problem, just removed the bulb and it works fine.


                    I use the current through the existing lighted doorbell switch to power a 12vac relay that close the contacts to a powerflash, works great.


                      Originally posted by swc69
                      Could I add a resistor to the circuit that would make "more contact" into "just enough contact"?
                      Steve, that is a fine idea, but you would still end up with an un-lighted doorbell. Also, it may be hard to predict how much resistance would be needed.

                      If you decide to live without the light you could:
                      1) Do as Barry suggests and get an unlighted doorbell.
                      2) Temporarily find a high enough voltage to permanantly eliminate the filament in the doorbell that you now have.

                      If you want the light, you may have to wire it in a conventional fashion. However, the load does not have to be a real doorbell.


                        After having a day to calm down and think about it I'll probably end up hooking it up the 'right way' with a proper transformer.

                        Since I don't have a real doorbell, there would would be nothing to load when the button is pressed. i.e. - it would be wired like the above shcematic without the doorbell.

                        Is that OK?

                        Steve C.


                          Originally posted by swc69
                          Since I don't have a real doorbell, there would would be nothing to load when the button is pressed. i.e. - it would be wired like the above schematic without the doorbell.

                          Is that OK?
                          It depends on the transformer, it could be dangerous. Without the bell, there will be a direct short across the output of the transformer while the button is pressed. If the transformer is limited in the amount of current it provides, you may be OK as long as nobody holds the button in for an extended period of time. If the transformer can produce a lot of current, it could burn out the contacts in the button and/or heat the wiring.

                          I would put a resistor in place of the bell to limit the current. It can also serve to set the brightness of the light.


                            A resistor would cause him to not have a light but and Diode may help in this situation. It allows current to only flow in one direction. Im not positive but you might want to try a diode on one of the Powerflash connections. This may or may not work because I am not familiar with the powerflash and am not sure which direction the current is flowing. But in therory from what you have described to me a diode should work just fine.


                              Would it matter if the powerflash was wired (looking at you picture) on the right of the of the transformer rather than the current left side?