[OpenTRV-dev] ELV offerings
EMAIL ADDRESS HIDDEN
Mon Feb 10 17:30:27 GMT 2014
Be aware that although the FHT80B controller can indeed control the
FHT8V and itself be controlled by the FHZ1000, the FHT8R-3 room
controller (also a thermostat/programmer), which is also sold to control
the FHT8V, cannot itself be controlled by the FHZ1000. This is not made
clear by Conrad or ELV, as they have acknowledged. As they look similar
and cost about the same they can easily be confused. The FHT8R-3 is in
fact a little smaller than the FHT80B (though you can't tell from the
website), and does not include a receiver.
The FHT8W works brilliantly, eavesdropping on the signals from the room
controllers to the radiators, and enabling the boiler if any of the
valves are instructed to be open above a threshold that you can set. It
is a part of my home-brew weather compensator setup.
In the end after a false start I standardised on the FHT8R-3 in each
zone as in practice I could not find much use for the FHZ1000. The
benefits come from managing each zone separately, so a tool that allows
you to make them all the same is not very useful. The FHT8R-3 has better
temperature displays than the FHT80B.
On 10/02/14 15:50, Thomas Hood wrote:
> On Mon, Feb 10, 2014 at 10:44 AM, Thomas Hood <EMAIL ADDRESS HIDDEN> wrote:
>> From ELV I recently ordered and received (within two days) a "FHT 80b
>> + Ventilantrieb + FHT 80 TF-2, ARR-Bausätze" which is a kit consisting
>> of semi-assembled FS20 wireless thermostat, valve head and window
>> sensor "almost ready to run". Cost 55 EURO. I have started assembling it,
>> taking pictures as I go. Has anyone else already purchased one of
>> these ELV ARR sets? The instructions are well written, assembly is
>> easy and the kits are cheaper than the assembled sets: the assembled
>> FHT8V-3  and the seemingly equivalent Conrad FS20 part  cost
>> 40 EURO. The some-assemblly-required ELV ARR kit is only 25 EURO.
>> If OpenTRV is going to be making use of ELV RVs for a while then this
>> is a way to lower costs slightly.
> I've been surfing around the labyrinthine ELV website. The FHT system
> has more possibilities than I realized. The FHT8V valve head which is
> normally controlled by the FHT80B wall thermostat can in turn be
> controlled either by the FHZ1000 (control panel) or by a FHZ2000
> gateway which in turn can be controlled by a HomeMatic CCU2 or by a
> PC. Although the FHT system has a boiler controller (the FHT8W), it
> has no occupancy sensing; but as part of a HomeMatic system I imagine
> occupancy detection could be used to make heating decisions. That's
> more than can be said even for the 2014 Honeywell Evohome system which
> overall is the most versatile and polished commercial offering (and a
> lot more expensive).
> Further surfing led me to realize that the HomeMatic system is also
> rather versatile. The old HomeMatic TRV is HM-CC-VD valve head +
> HM-CC-TC wall thermostat. The valve head looks exactly like the FHT8V
> but has a bidirectional radio that employs the so-called BidCoS
> protocol. This combination has been discontinued (although it's
> still listed for sale at Conrad) and has been replaced by the
> HM-CC-RT-DN TRV which looks more like other eTRVs. The HomeMatic
> system proper includes occupancy sensors but no boiler control.
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