VMB1TS in exterior condition, any advice?

Hi all,

I need to put an external temperature sensor, but even in a plastic box (to avoid rain and humidity), VMB1TS is very sensitive about sun. I’ve an other sensor near it wich is for heat boiler and it is less sensitive to direct sun.
My question is : could I open the cover of VMB1TS and give more inertie to sensor (by putting it in metal piece with glue gun) ?
Is that the right way (how exterior sensor are done ?) ?
Thanks for your advice (Velbus or users) !


hi Golfy,

is your second tempsensor for your boiler also a VMBTS or the standard ntc resistor that came with your boiler?
what i would do is to put the VMBTS in a white box (white reflects sunlight) with lots of holes in it and set it to the north side of the house somewhere under the roofending so to have always shadow on it.


Thanks for your help Stis :slight_smile:
The second sensor is the standard one coming with my electric boiler.
I’ve put the VMB1TS near it, on East face of the house (in fact, the wall do a ‘L’ with one face to north and the other to East. sensors are at 20cm from north’s face : unfortunaly, I can’t put it easely on north and I would to know which temp the boiler’s exterior sensor see…)

It seems to be an inertia problem as my 2 sensors are in same place but boiler sensor is more accurate (I’ve put a old thermometer on a north window).

Look at the T-Exterieure graph : it’s too bad :unamused:

I’ve tried to put a piece of paper + alumnium paper (turned out) and added some holes but the result isn’t here :cry:
bis-electric.com/catalog/ima … n-HP90.jpg


try to shield it with some wood so that is has always shadow on it. if you have one vmbts to spare open it and look if there is a ntc resistor in it. if there is glue a piece of metal on it. Best a piece of copper. i will try to findout myself if it has a ntc or temp-ic.

there is on the left lowercorner of the pcb a smd ic mounted. when you take off the front of the VMBTS then you will see a small piece of pcb sticking out with a small integrated circuit on it. this is where the temp is messured. glue a small piece of metal on it with instant glue and put everything in a waterresistant box. drill some holes in it to allow air passing by.


Yes, was thinking to something like this (here is what I was reading few time ago : reuk.co.uk/Make-a-Waterproof … -Probe.htm )

In fact, before doing anything, I was hoping that Velbus team would bring us an advice :unamused:

I don’t know if it is an option for you but I use an 1wie sensor to measure the outside temp. This sensor i 've placed in the same enclosure of the boiler sensor and gives me perfect results.
live example, updated every minute:

I also use those sensors to measure and log my boiler temps:

I think it’s easier to use those to measure other temperatures instead of struggling to modify the vmb1ts’s (and they are a lot cheaper to :wink: )

Thats sound great but are these sensors Ethernet compatible ?
Is it USB compatible ?
Because for now, all graph coming from Velbus (in my house)…

BTW, I’ve search 1WIE with Google but no site with temp sensor, could you verify if the word is correct ? thanks :slight_smile:

indeed, I forgot an “r”, it has to we “1wire”, the sensors are for ex ds18b20/18s20. There are many projects on the web that use those. There are various ways to interface, serial, usb, ethernet. An interresting project is for ex owfs.org. This is a server wich runs unther linux (it can run unther windows but it’s a bit harder), but as I can remember, you are a windows user. You could find lib’s enough to read them unther windows.

Didn’t u use a fitpc as server? I use the serial port of it with a ds2480 (on a pcb of elektor magazine), if you look a bit further, a lot of those components can be found as sample :wink:.

Does anyone know what temperature sensor is used as pcb?
Of the vmb1ts