Vaillant eBUS DHW & Cylinder Charge Temperature
Hi guys,
I notice that the Tado when setting hot water sets both the outlet target temperature and the cylinder target temperature to the same figure. Is this correct behaviour?
The Vaillant manual states the the actistor in my 938 cannot be set under 50oC for DH water, however the Tado appears to by pass this and can run the boiler tank to as low as 35oC. The Vaillant manual says this is to stop legionnaires. Is this something Tado are aware off?
Is it possible via Tado to set the outlet target temperature and the cylinder temperature at different temperatures (which I assume is what the Vaillant controller does)?
Sorry for the long post. What is also odd, is that the DHW temperature setting on the front of the boiler remains at whatever you set it to via panel. This appears to act as a maximum limit for the water, so if I set that at 55oC and then tell Tado to go to 65oC the command is not accepted fully and instead only increased to 55oC.
Any help or view much appreciated.
Answers
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I don't know if you misanderstood something or you have a different boiler/setup than what I have!?
AFAIK if you (can) set an outlet temperature than I would assume you dont't have a separate hot water tank but as you open (anywhere) the hot water, the boiler starts to prepare it?! I think that's the VUW series as in W for WATER. But don't take me for a word, I'm not an installer/technician, just an (wannbe) advanced user :-)
But, if you have a separate hot water tank then all your house hot water comes from it. Then on the Vaillant boiler you (can) adjust your desired target temperature for the tank. In this case the boiler will work 24/7 on keeping that water in the tank at that temperature.
Before getting the tado, I had a classic (Honeywell) setup, and the hot water was set up as I described it.
With tado you can set schedules for the hot water as for the room temp. Which is great, so you can program it to start heating the water let's say in the morning instead of keeping it warm all night and 24/7.
On my Vaillant you can set the HW temp to min 40, if you go below 40, it jumps to 15 (as in off/anti-freeze?).
As you said, in tado it starts at 35. And yes to me it seems also that they work in series. Like, if you set the temp on the boiler at 60 but at 50 in tado and if the actual temp is 55 then the boiler will not fire up until the temp falls below 50 and tade tells it to warm some water. BUT, if you set in tado the temp to 65, then (as you said) the boiler will heat only till it's set poit which in this case is 60!?!?!
That's my experience at least...
Also very important, at the very beggining of my tado installation the wall unit would display the ACTUAL/CURRENT water temp. in the tank, and on a further button press it would get to the point where you can change it. At that point I didn't had installed the phone app yet.
BUT, something was odd with the system (the diplay blinked like it was faulty) so the technicians updated the firmware and from then on no more knowing as what's the actual temp. in my DHW tank, only the desired set point...which is a total bummer!!
It's like not knowing what's the temperature in your house, only knowing that you want it at 23°C?!?!?
Oh one more silly/stupid thing...in the graph, you can see when the call for heat was, and that in three levels. For the HW when is red IT ONLY MEANS ENABLED!! I have solar panels and (currently 21.07.2020.) haven't been using gas to heat the HW for something like 2 months!! If I would have tado only enabled for the HW, it would show RED as it was heating the tank the whole time!!? Wouldn't you agree? Instead, it should show that red color ONLY WHEN IT HEATING (or call to heat)! Like is showing 3 shades of gray when is heating (or call for heat) the house!
Sorry for the long post.
Cheers
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Cheers for responding :)
My boiler is a storage combi boiler, thus has a 20L storage tank integrated inside the boiler. The tank and boiler communicate via ebus as one combined unit. In the installer settings I can monitor the outlet temperature and the cylinder temperature.
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