What does this Rehau add-on do?

darrenheaphy

Apologies but I did a thread about this previously but in hindsight it wasn't clear what I was asking and for some reason I can't edit it.

In the pic below I have a thermostat for setting the temperature of a room and a timer for defining hours of operation of the heat pump (under floor geo-thermal). But in the temperature setting there's a clipped on item that has three values:

1. Moon icon
2. 0 or presumably off
3. Timer icon

Not sure what they do and I can't perceive any change in the operation. Any ideas!?

heinbloed

It propably sends out a radio signal, being part of the Raumatic R System (concrete activation, heating, cooling).

The 2 others seen on the picture below are part of the M System (manual):

http://www.rehau.com/cms/servlet/linkableblob/DE_de/244308/data/ProductImage_478x478_OuGLMaDXGiiPZW3QSRFtFw__-data.jpg

darrenheaphy

Interesting, thanks heinbloed. I note in the image you sent that the attachment is actually there in the M product on the right so it's part of the system, which is good to know, just need to figure out what it does!

DGOBS

It appears to be the 'radio link' from the thermostat back to the controller (ones without it need to be wired back)

darrenheaphy

Ah ok. Forgive my ignorance but what would this controlled do? As I understand it the timer of the left controls the times on which the thermostat should be active and during those active hours the underfloor heating is active ...

heinbloed

The project has a number, a project ID. With this ID number you can contact Rehau. They have the plans, the drawings, calculation sheets. And the software in case you need it.

The device you're questiong about sends a signal, asking for the hot flow to flow.
This can be done via the circulation pump or the boiler itself. Or a combination of both.
Has the installer left any documentation? There is usualy a user manual with the equipment/heating system. Ask for this. And for the ID/project number, it would be found in the manual.
The heating system is hardly maintainable without the basic documentation. Unless you're a heating engineer and have plenty of time it will be difficult.
Like bringing the Mercedes to the plumber and asking to prepare it for the NCT.

As said: contact Rehau for a copy.

PS and OT: are there several of these particular devices installed in the same structure?

PSPS

The radio signal could also trigger the (zone-) valve. Or anything else.

darrenheaphy

heinbloed wrote: »

The project has a number, a project ID. With this ID number you can contact Rehau. They have the plans, the drawings, calculation sheets. And the software in case you need it.

The device you're questiong about sends a signal, asking for the hot flow to flow.
This can be done via the circulation pump or the boiler itself. Or a combination of both.
Has the installer left any documentation? There is usualy a user manual with the equipment/heating system. Ask for this. And for the ID/project number, it would be found in the manual.
The heating system is hardly maintainable without the basic documentation. Unless you're a heating engineer and have plenty of time it will be difficult.
Like bringing the Mercedes to the plumber and asking to prepare it for the NCT.

As said: contact Rehau for a copy.

PS and OT: are there several of these particular devices installed in the same structure?

Brill, thanks for that, I'll make a note and follow up with Rehau. Yes, there are various thermostats around the house but only that one has the attachment.

heinbloed

Then very likely it is the central thermostat. Starting and stopping either the circulation pump or the boiler/thermal source.
There might be a remote control around as well, similar the ones of a TV set.

Plenty of choice, check with the installer/Rehau.

Cedrus

darrenheaphy wrote: »

1. Moon icon
2. 0 or presumably off
3. Timer icon

Not sure what they do and I can't perceive any change in the operation. Any ideas!?

These are my guesses.

• Moon icon - I think this sets the night time temperature down lower than the daytime/occupied temperature (either by a set reduction or to a default temp?)
• 0 or presumably off - Sounds reasonable (unless it's O for On)
• Timer icon - Gives precedence to a time-clock upstream (on the manifold? on the Boiler?)

The changes on an underfloor heating are so slow you'd nearly need to keep a diary to notice them, if the thermostat doesn't click audibly (and hardly any of them do anymore) the only chance is to get a circuit tester in there.

There is also the chance, if it was installed in the tiger years that a more advanced model was installed (because it was available and no more expensive) but the full function was not required and also of course that it just wasn't wired up.