Vaillant VRC400 programmer,anyone familiar?

[Timmyturtle]

I have finally had an electrician to sort my extension wiring after running the boiler on a plug-top timer for 8 months

EcoTec plus 618 system boiler running a Vaillant aurostor 250L cylinder

Both are sited in the garage
I have no roomstat

The weather compensator programmer VRC400 has a temperature reading from the outside temp sensor in the bottom right of the programmers lcd screen

There is another (bigger)temperature reading on the screen which you can alter

In the manual it describes setting the room temperature ,but what i dont understand is what room is it talking about...The garage where it is or just a general living space required temp.

Just plain simple english please

Thanks chaps

 

[Balenza]

Timmyturtle wrote

but what i dont understand is what room is it talking about...

The room that the controller is installed in.
It states in the manual " The controller must be installed to ensure that it can properly record the room temperature..... The best place of installation is mostly in the main living room".

 

[Timmyturtle]

Problem is how many people have their boiler in their living room

Normally people plug these timers into the boiler

Boilers are normally placed in cupboards and utility rooms where the temperature is likely to be less than living spaces

What then should i set the temperature to for a garage(well insulated and eventually will connect the 1800x600 DP rad thats hanging there)

 

[Balenza]

Timmyturtle wrote

Problem is how many people have their boiler in their living room

No but you can have the controller installed in the living area where it can be set up to give optimum performance.
Sounds like you have had the cowboys in.

 

[gas4you]

The VRC 400 is best installed plugged into the front of the boiler, not in another room, although it can be, but works differently in this situation.

The set temp is just a general room temp that the boiler uses to set the flow temp from the boiler in conjunction with the current outside temp.

You should have the heating curve set between 2.6 and 2.8 for the UK and hopefully the outside sensor is on a north wall otherwise it will not work.

You need trvs on all the rads also. I presume you have had the VR65 control unit fitted as well otherwise you are not getting the full control between boiler, aurostor and VRC 400. Also you should have had the VR10 fitted to the aurostor whilst having the cylinder stat completely removed.

HTH

 

[Balenza]

gas4you wrote

The VRC 400 is best installed plugged into the front of the boiler, not in another room

Except of course when the boiler is installed in the garage as in the OP's case.

 

[gas4you]

Still the best place apart from having to go into the garage to set it up

It is designed primarily for plugging into the boiler front panel, where ever the boiler is.

It takes no room temp readings of the room it is in.

 

[Timmyturtle]

Outside temp sensor is as north as possible ,would be in direct sunlight if on the north wall

Yes im using the VR10 and VR65

Heating curve also at 2.8

Almost all trvs ( 2 old rads im changing xmas time have no trv)

So what should i set it to?Or is it worth asking Vaillant(not used their tech line yet)

Dont think of myself as a cowboy,but i do have the hat

If all else fails I could heat the garage,Rad hung allready and have 2 ballofixes waiting for connecting so wouldnt take long,and it will keep the cars warm

 

[Timmyturtle]

Think I may have read it wrong,basically it needs to be the temperature I want my house to be?
So 18 degrees in ok then?

 

[gas4you]

Sun never shines from the North thats why it has to be on north wall

Sun rises in the east travels through south and sets in the west.

Set temp for 23C and trvs according to what room they are in. VRC 400 doesn't care what room you are setting for, it is all theoretical according to curve set, set room temp, outside temp, flow and return temp.

I think you are missing the basic purpose of this as a weather compensator.

You should set the boiler rad temp to max and the VRC 400 will determine the flow temp for the system according to the outside temp.

When hw is called for the vr65 will override this and set the flow temp higher to enable the dhw to get to 60C or what ever you have asked for.

 

[Balenza]

Timmyturtle wrote

I have no roomstat

So what is interlocking the boiler when the internal comfort space temperature is reached ?.

Why ignore the "room temperature modulation" function available on this controller ?.

 

[Timmyturtle]

I dont have a fully north wall on my house but is as close as poss at the moment without sun getting on it.I have plans for more work which will allow proper fitment at a later date
The sun rises at a corner of my house but shines along the wall i would fit it to

The Trv`s work instead of a roomstat (well they will when all rads have them)The boiler works it out

The room temperature modulation is only for wall mounted installations

 

[gas4you]

So what is interlocking the boiler when the internal comfort space temperature is reached ?.

I agree this does not appear to conform to the interlock rules as we know them, but it certainly is accepted and ok for this purpose due to the modulation from outside temp etc.

Even I, as one of Vaillants main supporters, (at present) cannot explain in full detail how it complies.

'Phoning their tech line will not help as it is now run from Belper (Glow worm numpties) and they know even less than us installers

 

[Balenza]

Timmyturtle wrote

The Trv`s work instead of a roomstat

That's a good one Timmy.
I hope someone can explain it.
Surely Vaillant have a room sensor available which is compatible with this controller to give room temperature influence and boiler interlocking.

 

[gas4you]

Not at present and another problem at the mo is that the Vaillant system can only control one heating zone.

If you want more you have to fit independant programmable roomstats and revert to a conventional 's' plan with extra valves.