CONNEX thermostat issues

RouterOS General
1

Hi there,
I have been unable to get my Dimplex CONNEX wifi thermostat working on the mikrotik hardware.

I have tried numberous things to get this thermostat working. It just wont stay connected to wifi and just refuses to connect to the wifi IF mikortik router is present.

here is what i have tried. Paired it to an mobile access point (travel router) so I can get it work to begin with.

Scenario 1) AP (TravelRouter aka TR) is connected throught wired or wifi connection to my Asus RT86U or DSL Modem or Mobile Accepp point . Everything is awesome. Thermostat connects to the internat and I can control the electric heaters.
Scenario 2) AP (TR) is connected to the MikroTik router at location 2. The thermostat will no longer connect to the TR and thus no internet. Not able to control the heaters. I have tried to disable all the firewall rules.

In the scenario 2 i reconnect the TR to the same DSL router that is providing the internet to the MikroTik router and thermostat works great.

Something seems to be preventing to connect to the internet and the thermostat disconnects from wifi. Anyone could explain such behaviour?

2

Please post your config…
/export hide-sensitive file=anynameyouwish

Based on my own experience with multiple brands of smart devices (cameras, door locks, bells, thermostats etc…)

  1. Could be wifi - devices nornally work only on 2.4ghz networks or only work well on 2.4ghz networks and some require you stipulate N and not b/g or whatever…
  2. Could be a DNS issue
3

As the behaviour differs between the case when the AP is connected via Mikrotik and when it is not, I’d expect some DNS cache issue as I have seen two cases like that so far. Either the thermostat needs some portions of the DNS response that the Mikrotik filters out, or it has a lower/upper case issue (places FQDN to the query in upper/mixed case and doesn’t accept an answer where the queried fqdn is returned in lowercase).

So I’d start from this. I’d convert the dynamic dhcp lease for the thermostat to a static one, and then create a dedicated /ip dhcp-server network row for its IP address with dns-server=8.8.8.8. Of course DNS requests must not be redirected to the Mikrotik itself using dst-nat. Power cycle the thermostat to make sure it requests a new lease, and see whether it is better.

If the above does not help, the DHCP server itself may offer/not offer some option the thermostat doesn’t like/requires. Analysing this would require sniffing of the DHCP traffic both when the Mikrotik acts as a DHCP server and when the Asus does; in the latter case, Mikrotik has to just bridge the traffic between the Asus and the AP so that it could be sniffed.

4

I’m running standard config after resetting the router to vanilla (using quick set).

I’m not sure I follow the DNS fix. I tried setting secondary DNS to 8.8.8.8 already.

DHCP is not likely a culprit as the Travel Router (AP) is assigning the address.

5

Not secondary. 8.8.8.8 must be the only DNS for the device, so that its DNS queries and responses were not cached and modified by the Mikrotik.

Neither the travel router nor the Mikrotik must redirect DNS queries to itself.

6

In the dhcp server settings instead of putting the gateway of the Subnet, put in 8.8.8.8
Example instead of
/ip dhcp-server network
add address=192.168.0.0/24 dns-server=192.168.0.1 gateway=192.168.0.1

Do this
/ip dhcp-server network
add address=192.168.0.0/24 dns-server=8.8.8.8 gateway=192.168.0.1

7

Thanks all! It turned out this was the issue. My DHCP server had no DNS specified.