MAX! interface completed

Since last Thursday, I’m now controlling 6 ELV MAX! Radiator Thermostats. Yes! But to be honest, not everything about the the ELV MAX! Central Heating system is that great. Here are some of the ‘problems‘ I had to deal with.

F2 errors.

When a Radiator Thermostat is installed, it will do a so-called adapter run to check whether the pin of the heating valve can be moved and the actuating range is OK. If not, the LCD display will show an error (F1, F2 or F3). Nearly all my Radiator Thermostats got an F2 error; which means the actuating range is too high. Strange, because my Jaga radiators have an actuating range that’s smaller than the 4.2 mm actuating range of the actuator.. I found out that the actuator didn’t make contact in fully retracted position – that’s not good, cause this means that the actuator can’t make use of the full 4.2 mm to control the heating valve. The result is, that the actuator doesn’t reach the position where the heating valve pin can’t be pushed in any further, hence the actuator thinks the actuating range is too high… After measuring some dimensions, I concluded that only a small modification of 1-1.5 mm would suffice, so I took a Radiator Thermostat with me to the garage and used a hacksaw to cut a slice off the Thermostat:


It worked! I’ve done this with all my 6 Radiator Thermostats and they’re all running fine now, no more F errors!

Cube doesn’t know what time it is

This one was even more serious. The Cube doesn’t have a clock; it synchronizes with a time server on the Internet. Right; but if (for whatever reason) that synchronization fails, you could find yourself waking up in the middle of the night with your bedroom temperature set to a day temperature! That’s unacceptable of course. There seems to be a work-around for that, you know… power cycle the Cube on a Saturday at 10:00, and the weekly program will run just fine! Why? Because when the Cube can’t do a time sync, it assumes it’s Saturday 10:00; Bravo! I found this work-around on the ELV forum BTW, where quite a few ELV customers vent their problems with the ELV MAX!.

Actually, if you can’t do what I did (=developing my own weekly program functionality), this problem actually makes the ELV MAX! system completely useless.

Fortunately, I could start using the Radiator Thermostats, despite these issues… 🙂


DIY to the MAX

Sometimes it looks like you have to do everything yourself…

While testing the ELV MAX system, I noticed that the Radiator Thermostats were off-schedule quite often. I don’t know why, but it’s a fact, and I have to deal with it.

Totally wrong! The weekly program I used in the past days was specifically created to monitor the accuracy of the Radiator Thermostats. Every 2 hours the temperature set-point was increased with 1°C;  starting with 10°C at midnight, 11°C at 02:00, 12°C at 04:00 and so forth. This way I had enough switch-points to see how these Radiator Thermostats would perform. Well, as you can see, the temperatures are totally wrong! Grr.

Why? I don’t know. But they are, for some odd reason. And the worst thing is, there’s nothing you can do to resolve this. Once the Radiator Thermostats have a wrong sense of time, you’re doomed and you’ll have to wait (for how long?) till the Cube resolves this for you. Hmm.

It seems that the Cube periodically retrieves the date & time from a time server on the Internet, so I wanted to know how often;  I took an old 10/100 Ethernet hub and connected the Cube and a laptop with Wireshark installed to this hub. Even after 36 hours, only 2 IGMP packets were seen. Even a power cycle didn’t make the Cube check to see what time it was. Too bad, I hoped I could find something that would trigger the Cube to check the date & time, but I’m lost. The Cube will probably check date & time once every few days or even a week, probably.

But can I live with Radiator Thermostats that are totally off schedule? No, of course not! So I had to write my own code to handle the weekly program and use that to control the Radiator Thermostats, until there’s another way to get the RT’s (Radiator Thermostats) working the way they should.

Autonomy is good for things like controlling the temperature in the house; it should be able to function all by itself, without the need for a Home Automation system to constantly dictate what the temperature should be – only when the residents want to overrule the default weekly program, Home Automation should kick in in my opinion. For now, that doesn’t seem like an option with the MAX system. It just doesn’t look completely finished yet? So much for the “Deutsche GrĂĽndlichkeit”.. I guess this is another examples of a product being pushed to market a bit too soon..

Nevertheless, 4 new Radiator Thermostats are coming this way; moving on! 🙂