How to Add Z-Wave to Your Fireplace Switch

Looking for the best way to automate your gas fireplace?

So many relays, so many choices! We're here to help simplify your decision.

For gas fireplace installations, we recommend the ZEN16 or the ZEN17 over the ZEN51/52. Both the ZEN16 MultiRelay and the ZEN17 Universal Relay are installed at the fireplace itself, and both can handle the necessary low voltage and dry contacts for power, input, and output. When deciding between the ZEN16 and the ZEN17, there are a few considerations:

The ZEN16 has 3 NO relay while the ZEN17 has 2 NO-C-NC relays
For hardware VER 1.0 of the ZEN16, the switch inputs are fixed to the relay outputs and you can't monitor them separately of the relays. For the ZEN16 hardware VER 2.0 and the ZEN17 the inputs can be separated from the relays and monitor analog binary sensors for open/close, dry/wet, etc.
The switch inputs on ZEN16 are dry contact only which means you can't connect any voltage to them while there are 2 types of inputs on the ZEN17: dry contact (S-C) and low voltage 12-24 V (VC-C) to use low voltage triggers
The ZEN16 VER 1.0 uses the 500 series Z-Wave chip with S2 Unauthenticated security, the ZEN16 VER 2.0 uses the 700 series Z-Wave chip with S2 Authenticated security, and the ZEN17 uses the 700 Series Z-Wave Chip with S2 Authenticated security
You can find more differences and details here: https://www.support.getzooz.com/kb/article/1104-zen16-vs-zen17-what-s-the-difference/

Check out the step-by-step installation instructions here for using the ZEN16 MultiRelay to control your gas fireplace.

While the ZEN51 Dry Contact Relay may seem to be a good choice for automating your gas fireplace, we do not generally recommend the ZEN51 relay for these types of installations. The ZEN51 has a dry contact output only, so while it can be used to control the dry contact fireplace installation on the output, the input (switch side) isn't a good fit. A typical fireplace wall switch is connected to 2 low-voltage wires that close the circuit on the millivolt installation, and there's no 120 V power source in the switch box. The ZEN51 needs a 120VAC (neutral and live) to be connected to the L and N pigtails. The IN and OUT pigtails are truly a dry contact, and they are separated from 120VAC

If a fireplace switch, which is always low voltage, is installed next to a 120 V light switch in the same box, the ZEN51 could technically be used. In this type of installation, the power and input would be connected to the 120 V from the neighboring switch, and the low-voltage wires to the fireplace would be connected to the dry contact wires on the ZEN51. However, according to electrical code, any low-voltage connections need to be separated from high-voltage connections. This means there would need to be some kind of border between the 120 V and the fireplace wiring.

The ZEN52 does not have dry contact functionality at all, so it is unable to be used to add Z-Wave control to a fireplace switch.

Please don't hesitate to reach out with any questions! We're happy to help!