Thats the WSK-MLT, what fireplace model do you have?
I have wired up probably 1000+ of those things years ago.
Depending on what model of fireplace you have, you may need to stick with that control to use all the features.
BTW if just the keypad is going bad, you can replace just that part instead of the whole kit.
Do you have any more information about what is connected to that switch. It looks a bit more complicated than a simply low voltage toggle switch.
I got this, if I close my eyes I can see the wiring schematic burned into my brain 
@mavrrick58 and you are right that thing is way more complicated than a low volt switch. Controls flame height with a solenoid, blower speed, has a cold climate pilot option, built in thermostat, and can control aux lighting if the fireplace has it.
I have successfully fixed many keypads, switches, etc. What can happen is oils from your fingertips penetrate into the switch contacts. I carefully disassemble the device and clean the circuit board and contacts with contact cleaner. just did this last month for my sister's ancient ADT alarm panel.
I say this because that device appears to be expensive and as @jtp10181 said, I don't think you'll find a Z type device to replace it. You may want to ask Mike Maxwell, as I recall he automated his fireplace like 10 years ago, although not sure of the model.
I gave up trying to automate mine, it's a mendota with a "Sit" wireless remote. I thought I could capture the RF signal from the remote with my Broadlink RM Pro, but Broadlink doesn't even see the RF signal.
You could possibly automate it with a simple relay device depending on how many features the remote can control. Most of the stuff under the older units is controlled by just open/closing of a circuit, so easy to swap for relays. Newer controls are more integrated and would be more complicated.
Thanks Jeff.
I'm thinking I'd need at least 4 relays. The remote does on/off, back burner on/off, flame height, blower speed, light dimming , and some accessory control, that I have no idea what it is for.
Yeah I am familiar with that sort of setup. You could probably automate an on/off for monitoring and auto shut down but leave the rest on the remote, would be pretty complicated to replicate all the feature of the remote. Also some of the features may be integrated into a control module and not easily accessible to tap into. The accessory control is possibly for a feature your fireplace does not even have, like some sort of powered exhaust vent option, or a heat zone kit.
This is my remote. Any chance of getting programmatic control of these functions (fan speed, flame height).
My fireplace uses a standard light switch for on and off. I use this for voice controlled ON/OFF function with HE and Alexa.
@Pantheon when you turn off the switch does it cut all power to the fireplace, I guess easy way to know is if the switch is wired to low voltage wires or regular 12 Ga 110v wires? Hopefully its the low volt option, they are not supposed to be wired with switched 110v power.
I believe on that model the flame height is controlled by a stepper motor, would be hard to control without the control module that the remote talks to. You can probably hear it chugging along when you adjust the flame especially when going from hi to low. I think it gives you 3 height options? Unless it is just a clunk, then its a solenoid with hi/low only, but I think that remote is for the units using the step motors.
Fan speed is also done on the module (or an aux module) but if you disconnected it from the module any sort of Rheostat or Speed control rated for fans would work on it. The fans have the option to be controlled by a regular wall rheostat if the RC200 is not being used.
Thanks @jtp10181, I did find just the switch on Amazon for about $70 which I may get. But, would try what @Rxich is recommending. Maybe it's just the dirty switches.
However, I would still like to be able to control at least the on-and-off operation of this fireplace. Do you know if any relay can be added in parallel to this WSK-MLT controller to enable that?
I need to know the model of fireplace, should be a service cavity on the bottom with a silver rating plate attached to the bottom. There is a vast range of fireplaces which that keypad was used on with different control systems and features.
Or even if you post a picture of it I can probably identify it.
Update
@tushardeep I re-read your question, yes it would definitely be possible to wire in a relay to control the on/off. The wiring might be slightly different though depending on what model fireplace you have. Once I know how yours is wired up, I could draw on the WSK-MLT diagram how to add a relay.
I think you are completely correct, and it would be a very difficult task to undertake. Thank you.
Jef, Thank you. Do you know if my remote uses a standard RF frequency, like 345 or 434?
Probably, but I am not totally sure on that. I know in the past some fireplace remotes have known to get interference from Garage doors and other remotes, so they are possibly using a common frequency.
@jtp10181 , I am revisiting this. Currently, my RC200 remote referenced above will only do incremental changes in fan/flame. I would like to be able to command Alexa to set the flame to HIGH and/or the fan to HIGH (or any variations allowed). I was considering the Bond Bridge
But I get the sense that the RC200 unit does not communicate state. And therefore would have to be commanded to use step-wise flame/fan changes. And keeping those two devices in sync would be a challenge.
Yeah thats a general problem with the bond bridge. Usually if you switch to that then you don't want to use the normal remote anymore or the Bond will not know what state the device is in. Unfortunately with that IPI+ control system there is not a great way to tap into the level control of the flame or fan. I think you could wire something up to turn on/off.
You might be able to set the Bond up to just emulate the remote exactly. I assume each button press just sends the same signal to the receiver, to step through the settings. Every time it gets a signal is just increases by 1 or goes back to low if on high. If you were able to set up bond to emulate that maybe you could just have two command, adjust flame, and adjust fan. Of course the on/off as well. I am not sure if the bond software is setup to handle that sort of stateless control or not?
Yeah, the WAF would be pretty low for that one 
If you hide the normal remote and ONLY use the bond bridge (assuming it will work on the fireplace) then I think you could do what you want, similar to how a ceiling fan would work. You could always replace the fireplace remote with a 4 button zigbee remote or something so all control goes through HE / Bond. Might need some custom hacking to drivers and whatnot, not sure how it would work exactly but seems like it should be possible. Or maybe a Broadlink RM4 would be more customizable if it does the correct frequencies for that control system.
Ultimately, voice control is my goal. Good suggestions. I'll research a little further. Thanks.
The manual for that remote does not list the specs for the frequency, I think it should be on the labeling somewhere, isn't it required by the FCC or something? If not I might be able to dig it up somewhere.
Download the Hubitat app
