Central Heating Set up with Weather Compensator

likebikes · 7 Feb 2009

We are having a Valliant eco tec plus 831 boiler fitted with a VDC 430 Please could you advise the best internal place for this device to sit?( I appreciate that the outside temp probe has to go on a north facing wall). In the boiler or in a remote room? Presumably we will not need a room thermostat as this device already has one? Are there any further devices we will need? All Radiators will have TRVs

cheers

D_Hailsham · 7 Feb 2009

likebikes said:
We are having a Valliant eco tec plus 831 boiler fitted with a VDC 430 Please could you advise the best internal place for this device to sit?( I appreciate that the outside temp probe has to go on a north facing wall). In the boiler or in a remote room? Presumably we will not need a room thermostat as this device already has one?

Presumably you mean the VRC 430.

If this is fitted outside the boiler, it acts as a room thermostat, so it can be in any location you desire, hall or living room is the most usual. But, if it is installed in the boiler, you will also need the VR81 remote room temperature control.

All Radiators will have TRVs

The location with the VRC 430 or VR81 should not have a TRV on the radiator.

gas4you · 7 Feb 2009

Well you are the lucky one

VRC430's have been unavailable for many months and as yet I didn't know they were again available

I have fitted these and the 400 model, but I always fit to the boiler front and have trv's on all rads.

Never had the need for an extra room stat as yet. The 400/430 will set the room temp via the heating curve set and temp set/asked for on it.

likebikes · 9 Feb 2009

Thanks for getting back D_Hallsham and Dave I'll be informing our fitter with this information. This will be the first VRC 430 he has fitted!

D_Hailsham · 10 Feb 2009

likebikes said:
Thanks for getting back D_Hallsham and Dave I'll be informing our fitter with this information. This will be the first VRC 430 he has fitted!

Maker sure he reads the manual before installing it. It is very specific that, if installed in the boiler, it does not measure the room temperature.

If you think about it, it can't, as the temperature inside the boiler will be much higher than outside. So how can you set the room temperature to 20C with the VRC 430 in the boiler without something to measure the actual room temperature? The external sensor only measures the outside temperature.

naziern · 1 Mar 2009

I am considering the VRC 430 with a Ecotec exclusive. I am considering siting the 430 in the living room, but this operates a gas fire most of the day. Is this a problem?

My other choice is the hallway but its long and narrow at around 25ft, will have one rad approx 10-12ft away from my preferred site for the 430.

Thanks

gas4you · 1 Mar 2009

Yes, the gas fire on will probably make the 430 tell the boiler to switch off.

Go with the hall solution

likebikes · 17 Mar 2009

Ok
We now have the combi boiler fitted and hooked up to a VRC400. The engineer has sited the VRC400 in the kitchen. Here come the questions!

Am i right in thinking the WC should really be sited in the lounge or back installed in the boiler?
If it is fitted externally (in the lounge) then additionally i should do the following:

Turn the 'Maximum radiator Temperature control on the boiler fully clockwise. this apparently gives control to the WC?
Turn the TRV in the lounge to fully on
Adjusted Heating curve to 2.8
oh and what is 'Room Temperature modulation' ? do i need to enable this as well?

If the VRC400 goes back into the boiler then i should do the following:

adjust heating curve to 2.8
all radiators have TRVs so they will decide each room temp

given all this is it better to have the VRC400 external or in the boiler?

Sorry i have gone on a bit but the engineer dosen't seem to be able to help or is as confused as i am?

mickyg · 17 Mar 2009

fit the WC control in the boiler. Set all your TRVs correctly. Make sure the probe is correctly fitted on an outside wall as per instructions. heating control knob on maximum. 2.8 sounds quite high, but then might be suitable for your location. better to try it about 2.1 then raise it a little at a time if you find the rooms are not heating sufficiently.
then leave it alone and enjoy

AnimalGlu · 23 Nov 2009

D_Hailsham said:
The location with the VRC 430 or VR81 should not have a TRV on the radiator.

I've just realised that my VRC 430 that is located in the lounge has a TRV on the radiator.

Can't I just turn this up to full? In fact, all my TRV's are on full! Hmmm that might explain a few teething issues.

D_Hailsham · 24 Nov 2009

AnimalGlu said:
D_Hailsham said:

The location with the VRC 430 or VR81 should not have a TRV on the radiator.

Click to expand...

I've just realised that my VRC 430 that is located in the lounge has a TRV on the radiator.

Can't I just turn this up to full? In fact, all my TRV's are on full! Hmmm that might explain a few teething issues.

Yes. The important thing is that the VRC430 is controlling the room temperature, not the TRV. To quote the manual:

If the VRC 430 is mounted on the wall, the function "room temperature compensation" is activated and no remote control unit VR 81 is connected, take care:

– that the air in the room can circulate freely around the VCR 430 and that the VRC 430 is not obscured by furniture, curtains or other objects.

– that the radiator valves in the room where the VRC 430 is fitted are fully open.

"Room temperature compensation" means that the current room temperature is evaluated by the VRC 430 and is taken into account in the regulation.

If all your TRVs are on full, you might as well not have TRVs. Full on will mean a room temperature anything between 28 and 32 degrees, depending on the make.

AnimalGlu · 24 Nov 2009

D_Hailsham said:
Yes. The important thing is that the VRC430 is controlling the room temperature, not the TRV. To quote the manual:

If the VRC 430 is mounted on the wall, the function "room temperature compensation" is activated and no remote control unit VR 81 is connected, take care:

– that the air in the room can circulate freely around the VCR 430 and that the VRC 430 is not obscured by furniture, curtains or other objects.

– that the radiator valves in the room where the VRC 430 is fitted are fully open.

"Room temperature compensation" means that the current room temperature is evaluated by the VRC 430 and is taken into account in the regulation.

If all your TRVs are on full, you might as well not have TRVs. Full on will mean a room temperature anything between 28 and 32 degrees, depending on the make.

Okay, I've just got a digital thermometer, so I'm going to check that all my radiators are balanced properly and that both the outside thermometer and the VRC430 are monitoring temperatures accurately.

I'll let you know how I get on.

flycop2000 · 1 Feb 2010

Hi, please excuse me if these are simple questions?

I have just installed a Vaillant VRC430 (in boiler) and VR81 into Ecotec plus 831 combi but I'm not sure of some of parameters?

How do I know which curve to set?

On setup page A5, it states set parameter value 50c. Is this only to test the boiler fuctions or does it set max flow temp?

Am I correct in saying that outside and room temperature correction is to match the sensors by using a thermometer to get the correct temp and making adjustments in the VRC430?

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Central Heating Set up with Weather Compensator

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