Evohome range issues

[Cchris]

Been playing a little bit more. Using the HGI80 I have set up for Domoticz to monitor the system, I can see the messages from the offending HR92.

And I can also inject my own messages — I can tell the controller the current temperature for the zone, and I can send a heat demand message for the zone (and watch the controller then adjust the heat demand on the boiler relay).

So I think I can work around the dodgy RF reception between the controller and the furthest unit by just relaying the important messages.

This interests me greatly - and although techy, this is beyond me.

I had some mixed results - the dumb repeater didnt work full stop. Sticking the lift up flaps in the full open position seems to have improved things, in such that I did not have a disconnect from that room for some time. Several days in fact, when I was getting them up to twice a day.

Next step replace all the batteries with the lithium ones just in case the higher MAh allows for a slightly stronger signal to be pulled.

I also did some quick tests on the batteries that shipped with the valves (or the ones my installer put in). The current from the batteries that I had taken out of some controllers in another zone causing problems (the lounge) was around half that coming from a brand new set of brand name alkaline batteries. The voltage however was the same. So whether it was that the valves had drained these no name batteries before I replaced them, or whether they were just garbage batteries I dont know. The batteries still show as being full on the valves, so I assume its looking at voltage and not the available current.

Im going to replace batteries for some lithium ones and see if that also helps.

[paulockenden]

I don't think different batteries will affect your range issues.

Good news that lifting the flap helped - that's consistent with my mini-teardown of the hardware.

P.

[lineweight]

Have read this thread with interest as I've spent the last couple of days engaged in a battle to get an Evohome system to work in my flat.

It's not a big flat - the biggest distance between any two components is no more than about 5m but I was having real difficulties getting the system elements to talk to one another. I spent ages moving the location of the controller around, putting the boiler relay on a long cable, etc but not making much progress. Even at a distance of a metre or two with direct line of sight I was having troubles.

Eventually I realised that part of the problem was another system I have installed (data logging sensors with their own gateway box). When I unplugged this system's gateway box most of the issues disappeared. It operates on the same frequency as the evohome system.

But I need it to be operable, so I then started moving that gateway box around the flat to try and find a location where it caused the least interruption to the evohome. This was very difficult. I have now found a location where the interference seems to be reduced, but is still significant (if I unplug it, it's noticeable on RF test mode that the evohome components are talking to each other much more reliably).

When I do the RF tests, they generally rate the signal as "excellent" when it gets through. The problem is that maybe only 1 in 3 or 4 signals from the HR92s to the controller get received. The whole system seems very temperamental.

I get the impression that the HR92s pick up signals from the controller better than they are able to send signals back (changing the temp on the controller tends to result in it being updated on the valve display more quickly than the reverse).

It's hard to say whether the problem is mainly my datalogging system swamping the airwaves, or the HR92 transmitters being too feeble. But even with the datalogging gateway about 5m from the controller, and an HR92 only a metre away, there are still issues.

[Kevin]

I have the same problem and it's stopped me purchasing a largish evoHome system, pushing me in the direction of competing RF mesh based systems. Anticipating my wall thicknesses might cause problems I had range testing done by an evoHome installer who concluded I would need 4+ controllers which really makes the whole system impractical. A repeater offering is an obvious remedy and much needed but I spoke to Honeywell at the time and they said they had no plans.

I had hoped (and suggested) that the new WiFi controllers might be WiFi linkable to share zone control across the system avoiding having to actually access via multiple controllers which would have been a workaround of sorts - effectively using controllers as range extenders. Expensive but not out of the park in a large system.

K

[Cchris]

Kevin - what are the mesh based competitors? I admit to not doing a great deal of research beyond Evohome, but others that I have seen seem to operate on the same basis of 868mhz back to a single station.

Like you, I cant believe that Honeywell have no plans for a range extender. It really does make a system that would be very beneficial for large homes or those with thick walls (and would benefit most from reducing heating bills), a bit useless in large homes or those with thick walls. It really does seem like a ridiculous situation where a cheap extender box would make all the difference between selling a large installation and not.

I get the impression that the HR92s pick up signals from the controller better than they are able to send signals back

This is exactly my findings as well. When I do an RF test on a zone with three radiators, two valves will report signal strength (on their own lcd screen) of 4, and one will report signal strength of 3. At the controller, its either all three in "poor", or one of them occasionaly in "not received".

So its either the strength of signal from the HR92's, or the reception sensitivity of the controller. My money is on the HR92's having a lower strength signal.

[Kevin]

The main mesh contenders would use either ZigBee or Z-Wave for communication, although I suppose a WiFi solution would also suit me as I have good coverage with that.

I have been considering HeatGenius which uses the Danfoss Z-Wave TRV's. Earlier versions had some communications loss issues but the current LC13 versions seem resilient. I don't have complete Z-Wave coverage across my home so I would have to use a few plug in appliance modules to create a suitable mesh. I was all set to go on this but the HeatGenius Z-Wave network has to be separate to any other network you might already have, and nor can their controller operate in a primary/secondary role. So any home automation integration depends on their being an API available - which they have been promising for over a year now and still not released. There's a small concern over their hot water integration too.

So currently I'm remaining with a home grown solution of about a dozen zones using Danfoss LC13's and some wired zone / rad controls, and hoping one of the professional solutions will evolve soon to meet my needs. Some of my current zones would ideally be broken down into many smaller ones , for example I currently have all the bedrooms as one zone with standard TRV's in each room.

On your evoHome system is there any opportunity to run wired control to a zone valve(s) controlling your furthest problematic areas ? There are wired actuators that can replace TRV's or you can add them to the pipe run under the floor.

Re the quoted comment above it is likely that the HR92's use less RF transmit power than the controllers because of battery life considerations , hence the non symmetrical transmit / receive ranges. I did consider trying some form of diplexed antenna arrangement on an evoHome controller - with dual antennas extended with coax cables along the length of my home but my property has just too many aspects of it's construction for me to think that might work. A similar arrangement did help for a Z-Wave controller however. Supporting merging several evoHome controllers as one larger controller over IP would have been acceptable to me , even though it's costly. This is one way Homeywell could extend current range problems, by a firmware update. I don't want to have to divide my home into segments for overall control.

[paulockenden]

I still reckon an hci80 and a rPi could be used to create a repeater. The only problem would be some devices getting two copies of certain messages. Don't think that would be a problem, though.

I have an eBay saved search looking for cheap HCI80s. Missed a couple in Germany last week!

[lineweight]

In my fairly extensive research the only real competitor I found is Heat Genius. It looks like a more attractive system to me - has the ability to log data, and incorporate motion sensors for example.

The reason I went for Evohome was simply that it currently works out quite a lot cheaper than Heat Genius (for the system I need, at least).

This also looks promising:

http://istabai.com/

But they seem like they're only really set up to sell to installers at the moment - buying as a DIY-er might be a bit risky. Probably worth checking back on them in a year or two though.

There are lots of other potential systems but they all fall at the hurdle of including a boiler relay. They seem designed around continental European market where there's not generally a need for boiler interlock.

[lineweight]

I still reckon an hci80 and a rPi could be used to create a repeater.

Assuming it could be made to work, it might help those with range problems caused by distance between components. But I don't think it would help much for problems with interference from other systems. In my case, I still see problems with the controller and NR92 literally a foot apart.

[paulockenden]

But I don't think it would help much for problems with interference from other systems. In my case, I still see problems with the controller and NR92 literally a foot apart.

I think your other system is being unfriendly. EvoHome is deliberately only 'on air' 1% of the time. This (as well as saving power) also avoids clashes, even if other things are operating at the same frequency. But that's never going to help if something else is transmitting all the time.

Have you already mentioned what that kit is? because it's something that a lot of us will obviously want to avoid!

FYI, I have lots of other 868MHz kit here, but it co-operates just fine with Evohome.

P.

[lineweight]

I think your other system is being unfriendly. EvoHome is deliberately only 'on air' 1% of the time. This (as well as saving power) also avoids clashes, even if other things are operating at the same frequency. But that's never going to help if something else is transmitting all the time.

Have you already mentioned what that kit is? because it's something that a lot of us will obviously want to avoid!

FYI, I have lots of other 868MHz kit here, but it co-operates just fine with Evohome.

P.

It's one of these. It collects data from battery powered sensors that are embedded in the external walls. There are 6 sensors and it logs every half hour for each.

https://shop.omnisense.com/g-3-wireless-gateway-with-cellularoptional-wifi-and-ethernet

What I don't really understand is why it would be transmitting - surely it just needs to be always listening, so that when the sensors transmit it picks them up.

6 sensors transmitting every half hour each means a signal being sent by one of them every 5 minutes. However, it's not them that are causing the issue because unplugging the gateway (or discinnecting its antenna) seems to make my problems go away.

Unless there's something here I'm not understanding properly.

[paulockenden]

Sounds like your gateway is also transmitting.

Do you have the Cellular, or Wi-Fi only version?

P.

[lineweight]

Sounds like your gateway is also transmitting.

Do you have the Cellular, or Wi-Fi only version?

P.

Wi-fi only.

But wi-fi is a different frequency, isn't it? In any case, when I plug it into the LAN via ethernet cable instead of wifi, the problems persist.

[paulockenden]

So for some reason your gateway appears to be (continuously) transmitting on 868MHz, rather than just receiving from your sensors.

Might be worth checking with the manufacturer to see whether there's any way to stop this.

P.

[lineweight]

So for some reason your gateway appears to be (continuously) transmitting on 868MHz, rather than just receiving from your sensors.

Might be worth checking with the manufacturer to see whether there's any way to stop this.

P.

Yes. I think I might drop them an email and see what they say.