RF isense not working with Intergas HRE 28/24

Forum about Opentherm, Hvac, House heating, Boilers

Moderator: hvxl

RF isense not working with Intergas HRE 28/24

Postby semmyroundel » Sun Oct 18, 2015 11:34 am

Hi all, I'm sorry not to be in your league in knowledge about how to diagnose these issues, and desperately am trying to at least get a working setup even by buying a gateway.
The history is this: I have been installing Intergas boilers for a while now and insist on weather comp for my customers, originally I used the wired isense controllers (Remeha) and these worked fine. I recently tried to get a wired version only to find that I could only get the RF version.
The reason I stuck with the Isense was that (in my belief) there was optimisation included, this based on the fact that in advanced mode one can select the degree that the controller looks at weather comp in contrast to room control ( a varying degree could be selected allowing the end-user their own level of economy compared with extent of control).
I made up a voltage reducing circuit which I wired across the 24v pins on the intergas to power the RF Isense, this adequately powered the RFmodule, and it sprang into life, pairing the transmitter with the receiver, but that's where the connection ended.
The receiver constantly showed (after the connection confirmation LED flashes) 2 flashes which indicated "no OT connection received from boiler for 30 seconds" or words to that effect.
I should say that these Isense RF units are branded Baxi, but my belief as they own Remeha is that they're still made by them.
I bought three of the Rf units, two have gone back as I couldn't get them to communicate with the Intergas boiler.
Worryingly, I had a look at:
and there it looks like the intergas boilers don't support Code 9, which, unless I'm mistaken is the important one for communication.
Even worse, I've now had two Intergas combi compact boilers suddenly show F203 (loss of communication of OT).
The aforementioned boiler with the RF Isense was a system boiler (if that makes any difference).
I'm REALLY desperate as these boilers are losing control all around me and I'm starting to look really incompetent.
A few years ago, I went to the Theben factory in Stuttgart with my fellow Ectechnicians and they waxed lyrical about the OT compatibility of their products, although their real gameplan was to push KNX.
I've looked recently at the Ramses 850 top 1 as a wired replacement for the isense, but that apparent lack of compatibility on the tclcode.com website now makes me question it all.
Please help if you can, the picture is bigger than just me as there's lots of people awaiting my successful outcome on this.
Many thanks in advance.
Starting Member
Starting Member
Posts: 1
Joined: October 2015

Re: RF isense not working with Intergas HRE 28/24

Postby D_Hailsham » Sun Oct 18, 2015 3:49 pm

I assume you mean Opentherm ID 9 when you say "Code 9".

ID 9 is not essential as it is only used for "remote override of room setpoint" and is used in conjunction with ID 100. In normal use, where the OT themrostat is connected directly to the boiler (ibase in the case of the RF iSense), ID 9 is irrelevant.

Are you taking the 24V supply for your voltage converter from X4/6 & 9? Have you checked that this is a permanent and clean supply (RF systems need a constant supply)?

If the boiler supports OpenTherm Version 3 you do not need a separate power supply.

You can also power the ibase by using an external 6v supply, e.g the type used for routers etc.

Have you raised the problem with Intergas?

What do you mean when you talk about "optimization"?
Starting Member
Starting Member
Posts: 35
Joined: August 2013

Return to Hvac, Heating Opentherm Forum

Who is online

Users browsing this forum: No registered users and 1 guest