Vaillant vrc430, vr81, vr61

[ALEC1]

the vr61 should control the mixing valve and the pump on the mixed circuit, and only the pump on the unmixed circuit. Its the esbe mixing valve that is critical!

the 430 only acts on the unmixed circuit, the vr81 on the mixed circuit.

its always problematic mixing on-off controls with modulating controls.

what heating curve have you got the mixed circuit on (should be about 0.5-7)...the radiators will need to be higher..(1.2-1.8 or higher..)

waiting to be corrected on all this!

 

[joncox]

My UFH heating curve is 0.4, and 0.6 for the rads (which are oversized)

 

[ALEC1]

ok.. thats cool

it all depends on many factors...the lower the better, with a higher set back temperature seems to work best!

John cox is it on a Low loss header...?

 

[Black90]

I plan to run 40m2 UFH and 12 rads. Vaillant recommended low loss header to keep weather compensator, flow temp, happy.

Barry, doesnt the boilers internal diverter valve change over, as soon as hot water is called for? It shouldnt need to wait for the external zones valve.

 

[BarryCambs]

The divertor moves straight away when the tap is opened as I remember, but the VR61 seemed to be waiting for the zone valves to close before it fired the boiler.

Luckily, as I said, the floor heating seems to work fine coming on at the same time as the rads, so I'm happy with the setup.

 

[JoeMar]

hi all

i have now finished working on my heating system and though i'd share what i've done as there appears to be a few people interested in vaillant systems.

My set up is, Ecotec 937, VRC430, VR61 - 8 Radiators and 3 zone UFH (100m each zone)

As an experiment the system is currently running as one Heating Circuit (ie: no separate circuit for Rad and UHF) the idea is that i let the TRVs control the rads and the VRC430 to control the UHF.

the VR61 controls the UHF pump.

until now the everything is behaving correctly but will have to experiment with heating times when winter kicks in properly.

 

[Gabor]

Hi!

Following on, does anyone know a way to have a Vaillant system boiler control 3 heating zones in addition to a hot water cylinder? I have three floors, each with different insulation characteristics, so I thought a 3-zone system would be best with separate temperature controls on each floor combined with a weather compensator. But the VRC430/VR61 combo only does 2 CH zones.

All three floors have radiators, and I would like the temperature to be measured by sensors (one per zone, so one on each floor) rather than TRVs so that it can be programmed centrally.

Any pointers would be appreciated.

Gabor

 

[bell824]

you would be looking at the vaillant vrc 630 control module with seperate vrc room stat's for your zones.

Pricey but if it vaillant controls you want this is what you need!

 

[Gabor]

you would be looking at the vaillant vrc 630 control module with seperate vrc room stat's for your zones.

Pricey but if it vaillant controls you want this is what you need!

aye. Thanks. I guess it does what I need, and 10 times more...

I really don't need Vaillant controls per se, would it work with another company's 4-channel controller? Browsing around on the web I came across the Horstmann 4XL, also a weather compensating controller by Honeywell.

 

[bell824]

Only vaillant weather compensation controls work on vaillant boilers, but in saying that any other 4 way control system would work with vaillant boilers.

So in short yes it can do a lot of stuff you don't need but for weather compensation and proper integration with the boiler it is the only thing.

 

[Gabor]

Only vaillant weather compensation controls work on vaillant boilers, but in saying that any other 4 way control system would work with vaillant boilers.

So in short yes it can do a lot of stuff you don't need but for weather compensation and proper integration with the boiler it is the only thing.

I may yet bite the bullet. I guess what I don't understand is that if the external temperature sensor is wired directly into the boiler (as it is drawn on the Vaillant diagrams, eg in the VRC430 manual), then it will act to reduce the forward flow of out of the boiler according to the heating curve. How will the storage tank get heated properly? I was under the impression that the weather compensation must therefore act at the motorised valves of the heating circuits, rather than directly at the boiler... is this not so?

 

[bell824]

totally incorrect, what the vailant weather compensation does is it gives hot water priority (if used with the vaillant vr10 sensor) heat up the tank to the desired temperature with full power, then the weather compensation kicks in for the rest of the circuits as per heat required.

 

[Gabor]

totally incorrect, what the vailant weather compensation does is it gives hot water priority (if used with the vaillant vr10 sensor) heat up the tank to the desired temperature with full power, then the weather compensation kicks in for the rest of the circuits as per heat required.

Ah ! Hence the need for compatibility since the logic is complicated. Got it. Thanks!

 

[MarkusKuhn]

While the system worked with the Vr81/61, it wasn't really suited to the combi. The lag between turning the tap on and hot water was too long, due to the system waiting for the motorised valves to close on the heating every time before firing up for hot water.

Was the problem that connecting an external motorized mixer valve via the VR61 caused the combi to wait longer before switching from heating to hot water?

I don't understand why it would have to do that. After all, whenever the combi boiler switches from heating to hot-water, a fast internal diverter valve disconnects the radiators from the boiler circuit, so it should not matter in which position the VR61-controlled external mixer valve for the UFH circuit is, right? Why should it wait for that?

How can the boiler even wait for the VR61-controlled motorized mixer valve? Does the VR61 get via the 3-wire motor-on/motor-off connections of the mixer any feedback when the mixer has completely opened or closed? (I guess it could sense the current flowing through the motor and decide that it has reached its end position switch when that goes to zero.)

What exact motorized mixer valve did you use? How long does it take from open to close?

(I was extremely interested in your report, as I was about to try the same setup ...)

Markus

 

[MarkusKuhn]

The divertor moves straight away when the tap is opened as I remember, but the VR61 seemed to be waiting for the zone valves to close before it fired the boiler.

Just for the record: I have now build a similar system and did not encounter this problem. My VR61 does not wait for the UHF mixer to close before firing the boiler, and I never had any problem with hot tap water being delayed in any way by the addition of a VR61 to this combi boiler to control the motorized mixer of a UFH loop. I warmly recommend this setup, it works very fine for us.

Details:

- Vaillant ecoTEC plus 831 condensing combination boiler, installed 2011 ("base" firmware version: 1.34)
- Vaillant VRC430f weather-compensating controller (firmware: 1.20)
- Vaillant VR21 outside temperature sensor (firmware: 1.15)
- Vaillant VR61/4 mixer controller, installed 2014 (firmware: 4.18)
- Uponor 1059839 Pumpgroup PPG-20 (includes Wilo Yonos PARA 25/6 RKA 180 pump)
- Uponor 1002357 230 V 3-point mixer actuator (= ESBE ARA661)
- Uponor 1002202 3-way FM manifold

(By the way, we use the VRC430f in open-loop control (screen C8: "Switch-on room temp.: None"), that is both the radiator and UFH flow temperature are solely determined only by the outside temperature and heating curve (i.e., we do not use any room temperature sensor and did not install any VR81). Works fine with correctly adjusted heating curves.)