HC3 crashing everyday

[Nathan Hall 0]

Hi,

I've been using HC3 for just over 3 years now.   Whilst I love the system, it has also always been a nightmare.  Our electrician installed a full home automation when we built this house and it has had so many issues that I've forgotten half of them and just when a software update resolves all issues and everything is finally working like it should, out of the  blue, another issue arises.

So now, I'm hoping someone can help as Fibaro don't reply to emails or have any concern to rectify.  I now have to reboot the system daily if not twice daily.  Scenes stop working and in some cases the system goes offline and I have to hold the button on the back of the HC3 to put into recovery mode to reboot.

I've just rebooted now so that I can lock our front door tonight or have lights operate, but it could be any moment now that I'll have to reboot again.

Oh, I forgot to mention devices like our roller blinds lose connection and am forever having to remove them and re-add them which means going though all scenes to add them back to scenes and everything else associated with each device.  I have spent literally hundreds of hours re-doing things that have already been set up and I feel like I will have this nightmare for the rest of my life.

Any help is much appreciated.

[Łukasz997 117]

I sympathize, because I’ve also had similar problems (resolved partially when switched ZW3 -> ZW2, and finally after excluding Danalock V3 from the network). It’s understandable that you’re writing in an emotional way. But some specifics would be useful: what used to work before and what doesn’t work now – at least one or two examples. Maybe that could point to the cause – after all, there must be a concrete reason for this situation. From the way you describe it, it seems the problem might concern Z-Wave communication. Do you know which version of Z-Wave you’re using? Are all your devices Fibaro? Have you recently added other device? Could you point out the moment when the problems first started?

One advantage of wireless communication is the possibility to dynamically expand the infrastructure at any time. But the price you pay is, for example, the possibility of communication problems.
There is something called ZNIFFER for analyzing Z-Wave networks. There are a few people here who know this subject very well, unfortunately I’m not one of them.
 

Edited October 3, 2025 by Łukasz997

[Nathan Hall 0]

Thanks for your response.  Basically everything is Fibaro.  Roller shutter 3, single and double light switches.  I cannot say that there is a concrete reason.  Everything is working fine right now.  Later in the day, scenes will shut down and I will have to reboot the system for everything to work again.  I wish I could give more information as to why this is happening, but so many various issues have happened for over 3 years straight and it just seems it will never work.  By the way, our electrician hid all of our light switches in cupboards, so I can't just bypass the HC3 to operate this house as normal.  Same goes for our front door lock, heating and cooling, and roller blinds.  There is no alternate way to operate anything in the house.  It's all controlled by the HC3 and when it goes down, we're locked out and in the cold and the dark.  Not to mention that we can't even send a roller blind down in the bathroom, so anyone that wants a shower is fully exposed.  It's all just a joke.

[Sankotronic 2,370]

Hi @Nathan Hall,

 

If I'm not mistaken, scenes usually stop working if free RAM is very low. For RAM to fill up there must be either quick app or scene that has some flawed coding.

Another thing to check is z-wave. If there is any device that is flooding network with unnecessary communication it can cause lots of trouble and needs to be checked.

 

It is same problem with all systems that are open for user configuration and programming.

 

For starters, you can write a bit more important information about your system that can be found on HC3:

 

1. What z-wave engine you are running on v2.0 or v3.0? (You can find this information under Settings option 9. Connect gateways)
2. How many z-wave devices are included in your system and list of those not manufactured by Fibaro?
3. Size of the house matters, same as layout and position of the HC3 gateway. mains powered z-wave devices can serve as signal repeaters for those devices that are far from gateway. Was your z-wave network build with that in mind?
4. Check under 10. Diagnostics z-wave tab and report if there is anything unusual or is any device is sticking out of the ordinary?
5. How many and what plugins are installed? (Not Quick apps but plugins)
6. How many Quick apps are installed? (can be checked in Settings -> 5. general -> main tab)
7. How many scenes are running and what type (Block, LUA, Scenarios)
8. Under diagnostics Total CPU usage check if all CPU are always very busy, above 50% or something
9. Also under diagnostics check RAM usage and if it is raising, but don't look at Current usage on the left, but RAM capacity on the right.

From what you write about your system, I would suggest to redo everything from scratch and make sure that this time switches and everything else is not hidden in cupboards. Home automation should be always done with possibility to still do things manually in case that something bad happens with gateway. That is how I did my house, even in 15 years with Fibaro we had only once our Home Center 2 down for almost a month, but my family could still live normally, just doing everything manually  It was down for that long because I was away for work.

 

If your z-wave is on version 2.0 then eventually you will have to change to v3.0 since v2.0 will not be updated anymore and therefore new devices will not be able to work as expected.

 

BTW - do not expect much from Fibaro support since they can't cover and do not need to cover all cases of badly built systems. On the other hand they do provide education for electricians (installers) that should be able to help and do reliable systems.

 

If that is not the case, then there is no other options but to educate ourselves a bit about wireless communication and learn to make better LUA code  or at least find some source where to learn like this forum. Here are many members that are very good in understanding of this system and LUA developing and are eager to help others.

 

 

[Łukasz997 117]

But in the current situation, I would add one more thing: I think it would be better for you to reach out to a local Fibaro specialist (I hope such a person exists). They don't have to come to your house - even a remote connection could give a good picture of the system.
 

By the way: I had terrible problems with Z-Wave 3.0 about a year and a half ago. After switching back to the older 2.0 standard, the issues disappeared (it was about communication between the hub and Fibaro thermostats). Z-Wave 3.0 was the only cause. Because of that, I’d like to ask: does anyone know if Z-Wave 3.0 has finally come out of the beta stage and is stable now?
Is it safe to migrate the system to 3.0?
I’d be very grateful for any answers.

[Sankotronic 2,370]

Hi @Łukasz997,

 

I do not have any z-wave devices included to my HC3 at this moment, so I can't say if it is safe to migrate to 3.0. All I know that 2.0 engine is EOL and will not be updated anymore. Actually Fibaro already decided that "Z-wave engine 3.0 is set as default in the FTI process." Also I can't see word "beta" anywhere in the HC3 interface regarding z-wave, so I guess it is out of beta.

 

I do expect that some devices are still not completely supported, but since development team is now focused on 3.0 engine I do expect that they will be with at least next stable version. Of course @m.roszak can give more info on that subject. Also there is some useful information at 

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[Nathan Hall 0]

Thanks so much for taking the time to help me with this and sorry for the late reply.

Low free RAM makes a lot of sense as to why scenes might shut down.  How would I know what is using too much RAM and how do I reduce it?

It seems that the Zwave engine is v2.0, but it's showing that on the HC3L under the Connect gateways settings section.  See my screenshot.  I'm not sure how to update it.

We do have a fairly large house, but I thought that each device was close enough to connect to each other.  There has been a few times that a motion sensor has lost connection and I've re-added it to the HC3L which is at the opposite end of the house and they have stayed connected so far.  Almost all devices are mains powered other than 2 door opening sensors.

I haven't really had anything to do with plugins, so I don't know much about them, but I'm pretty sure there are none.

Under General and the Main tab, it says there are 10 Quickapps.  If I search in devices I can only find 8, which are for climate control.  I'm not sure what the other 2 are.

There are 86 scenes in total, all are block scenes except for 1 which is a scenario.

CPU doesn't seem too busy at all.  Should it be above 50% like you mentioned?

Redoing everything from scratch wouldn't be possible.  It's quite a large house and with the design and style, access into roof spaces wouldn't be possible.  The wiring set ups are permanent.

I can't seem to find how to update the Zwave engine.  How is that done?  It's 2.0.

 

Many thanks again.

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[SmartHomeEddy 1,005]

Well, the figures all look ok. 

[Łukasz997 117]

Could you send screen from Diagnostics/Zwave sorted by failed communication?

[Tim__ 126]

Hi @Nathan Hall, It's tempting to blame the hub hardware manufacturer when things aren't working, but there are more pieces to the puzzle than just Fibaro. You'll need to break things down to find each problem and then solve it. In my experience this can be quite time consuming (and a learning curve), but once I did this the system has been very stable. Your other options are to call the electrician back and get him to fix this, or rip it all out and start again (in my opinion, this is not necessary though).

 

It looks like you have two devices, HC3 as master and HC3L as a slave? Which box is crashing? Firstly I would check that you aren't exceeding the recomended device and scene capacities. Eg If you have 83 scenes running on an HCL3 then you are 4 times over its capacity.

 

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Scenes (I'm mainly talking LUA ones) can have coding bugs that cause crashes. You can identify these by disabling a bunch of scenes to see if the system becomes stable, and narrow it down from there. Though you have said you've got no LUA?

 

I have also had roller shutters periodically drop off the network, though it only ever happens to Qubino branded ones. I put this down to bad Quibino firmware. I had to use Qubino as only they supported low voltage DC roller shutters.

 

Finally I'm going to suggest that your electrician left you with a half installed system, and really they should have completed the job properly in the first place.🙁

[Mike MJ 3]

 I was going to suggest that you examine the number of devices and scenes on the HC3L as suggested by Tim_@. I have a new house as well. I installed a HC3 up-stairs and a HC3L downstairs. Both are running on ZWave Engine 3  90 devices on the HC3 and 30 on the HC3L are connected , mostly Fibaro .All are up to date with their firmware. I only use block scenes ( 70) plus 3 Quick APS.  As far as I’m aware all scenes run on the HC3. I have excellent wifi coverage across the house which provides strong wifi connection between the 2 hubs. I’ve had quite a few problems getting every thing to work but after stepping through each issue over the past 12 months I now have a pretty reliable system.  So our systems are similar in size and complexity but your running Zwave engine 2 . After spending the past 12 months debugging the sustenance I have a lot of empathy with your position. One question … are you examining the History Log every time the system goes off line. I found that useful on a few occasions?

[Nathan Hall 0]

On 10/9/2025 at 9:13 AM, Tim__ said:

Hi @Nathan Hall, It's tempting to blame the hub hardware manufacturer when things aren't working, but there are more pieces to the puzzle than just Fibaro. You'll need to break things down to find each problem and then solve it. In my experience this can be quite time consuming (and a learning curve), but once I did this the system has been very stable. Your other options are to call the electrician back and get him to fix this, or rip it all out and start again (in my opinion, this is not necessary though).

 

It looks like you have two devices, HC3 as master and HC3L as a slave? Which box is crashing? Firstly I would check that you aren't exceeding the recomended device and scene capacities. Eg If you have 83 scenes running on an HCL3 then you are 4 times over its capacity.

 

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Scenes (I'm mainly talking LUA ones) can have coding bugs that cause crashes. You can identify these by disabling a bunch of scenes to see if the system becomes stable, and narrow it down from there. Though you have said you've got no LUA?

 

I have also had roller shutters periodically drop off the network, though it only ever happens to Qubino branded ones. I put this down to bad Quibino firmware. I had to use Qubino as only they supported low voltage DC roller shutters.

 

Finally I'm going to suggest that your electrician left you with a half installed system, and really they should have completed the job properly in the first place.🙁

I've had the electrician back here several times and caused him a lot of grief over this also.  He has spent countless hours trying to resolve things.  Ripping things out and starting again is not an option.

All scenes are on the HC3, no scenes at all on the lite.  What would the capacity of scenes be on the HC3 alone?

And yeah, no scenes are LUA.  

So the other day when I noticed scenes not running, I noticed the CPU was running differently so I took a couple of screen shots.

Then rebooted and all back to normal until next time.

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[SmartHomeEddy 1,005]

That doesn’t look ok. 
 

So disable one by one all your scenes and quickapps and look what that does. Or the other way around, disable all stuff and enable one by one. 

[SmartHomeEddy 1,005]

Look like some “bad” programming is killing your cpu. 

[Nathan Hall 0]

6 hours ago, SmartHomeEddy said:

That doesn’t look ok. 
 

So disable one by one all your scenes and quickapps and look what that does. Or the other way around, disable all stuff and enable one by one. 

Ok, thanks, but they are all enabled now and there are no problems.  All cores of CPU are running between 2% - 8%.   It just suddenly happens without notice.  If I disable all scenes now and start enabling one by one, I don't think the issue will occur.  Maybe it's a scene at a certain time of the day.  I'll keep an eye on things there to see if anything consistent happens maybe.

I'm not really familiar with quickapps so I don't really understand a lot about it.  Are they like a virtual device?  These are the only quickapps I could find.

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[SmartHomeEddy 1,005]

On the Homecenter 2 they were called virtual devices, so you could call quickapps virtual devices. Quickapps could be full of Lua code, so could definitely be a source of a lot of trouble. 

 

You have to start somewhere. If you do what you have done up til now, you will get what you got up til now. Two cores at constant 100% doesn't fall from the sky. There must be some routines that starts going crazy, and it sounds like more than one. 

 

 

[Nathan Hall 0]

So, this time I've noticed a spinning buffer at the top of the sceen.  It is there for any screen.  This time around it's happened in the middle of the day.  Before I reboot, I'm trying to disable scenes, but the page won't load for me to do so.  Then, I have the bad gateway notification.

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[Sankotronic 2,370]

Today's browsers sets hidden tabs to inactive state to free some memory and reduce CPU usage. I noticed that after some time when I select my HC3 home page tab it doesn't refresh anymore and Firefox tends to give me warning that it is using lots of resources and ask me to close it.

 

So, it is necessary to refresh page whenever you get back to previously opened HC3 home page. Sometimes it will show login page because session expired, but it is not shown on browser since page is set to inactive state.

 

On Chrome under performance settings it is possible to set some sites to always stay active and that helps with HC3 home page. I try to find same settings on Firefox, but could not find anything similar so when I use Firefox I always refresh page. It also helps if you don't have too many tabs and reading panes opened at the same time even most of them are inactive.

 

I wrote this because part of the problem could be communication between HC3 and your browser. If there is a problem then CPU usage can also spike same as it almost always spikes when at the moment when Diagnostic panel is opened.

 

Next thing is that I see 63 notifications waiting for you to be read and checked. Can you do that and see if there is any critical notification? I would also check warnings just in case. Maybe you can share your findings here with us?

Also there are 5 updates waiting. Since your HC3 is on the latest firmware update I guess this are device updates. Can you check which devices can be updated?

 

It is also noticeable from your screenshot that there are some z-wave devices that do not communicate with HC3 and have red circle on their icons. Are this devices just physically turned off with wall switch or are problematic ones that occasionally loose connection? Or this lights and door sensor are actually included to the  HC3L slave that has some problems with communication with master?

 

Also, what connection you have for both gateways? Wired is always much better than WiFi. Are both on wire?

 

Also when you are in the Devices page you can filter devices by protocol and filter out QuickApp devices and see how many are installed. You can then disable them one by one with the checkbox Device disabled on the Advanced tab and see if there will be any improvements.

 

 

 

[SmartHomeEddy 1,005]

I think if its CPU is all at 100%, he won’t get an answer. Busy with doing something else. 

[Mike MJ 3]

Nathan I’d take a “step by step” approach to try to determine the issue here. There may not be a single answer to your problem. First there are 5 devices showing on your screenshot that indicate they are not up to date with their firmware. I’d fix that.   Secondly the 5 devices showing a red dot on the icon are in a location called “shed”. How far away from the HC3 or HC3L are they.   Are those devices involved in scenes ? Have you examined the history log of events immediately prior to the HC3 shutting down ?   There is a chance that if you check this every time the system goes off line you might see a repeating pattern.   It would be useful to share the screen shots so the other guys seeking to help can see the info as well.

[Nathan Hall 0]

So just in the last 10 to 15 minutes it's done its thing.  Scenes not running, CPU at 100%.  So I go to the history, but can't see anything out of the ordinary.  Just regular motion detection, lux readings etc.  No heating or cooling is running and general scenes being triggered through motion detection.