Vaillant Expert/Installer Question Weather Compensator.

[processpaul]

I had an 831 combi installed in early 2010. Very pleased with it I have to say

I have been considering whether or not to get a weather compensation installed to replace my current Honeywell wireless CM927 thermostat.

The house is 1930's mid terrace, with loft conversion, double glazed and cavity wall insulated. rear faces south west, I have an ground floor flat roof extension at the back with one wall that faces nearly north west it is quite sheltered behind this wall. Could the temperature probe be sited here or not?

Would the new VRC470f fit my older boiler as I have found on website that says it will only work with the latest 8 series models?

I had read some posts that the older VRC430F is not that user friendly. Any comments on this.

Thanks

 

[ALEC1]

user friendly is very subjective...I struggle with virgin media I player, but heating controls a real breeze...mostly..especially with the instructions...

430 is fine as is the 470..

When I pushed vaillant for compatability issues I was told that it only related to the connection, the 470 wont go in the fascia of the boiler...hardly a big issue...indeed I have a 470 with an older 630 boiler all is fine...

So yes it will work..


treat youself to the rf version..

 

[mysteryman]

North west should be OK. Keep it shaded from the south if possible.

 

[processpaul]

Thanks for replies

ALEC1, with regard to the "RF version" which one is that, cant seem to find that model only the VRC 470 and the 470f which is the wireless one.

I note that the Vaillant site also says the outside reciever is solar powered, so no cables to it are required. the only install manual i can find does not mention this though?

I can only find the VRC470 installation manual online, not the 470f...? Anyone got a link.


Cheers

 

[simond]

The VRC470 came out in Nov 2010 and was fully compatible with their boilers then...... the new model ecoTEC 6/8/9 series came out in April 2012 and VRC470 remained unchanged.

 

[Agile]

"RF" means radio frequency which is the same as "wireless".

The outside unit is a transmitter!

The Vaillant W/C controllers are quite expensive and will take a while to repay the cost if added later and particularly if it means discarding a paid for 927 stat.

Its always best to install W/C when a new boiler is fitted as thats always the cheapest option.

Tony

 

[processpaul]

Tony

Thanks for your reply, I see RF (should have thought of that!), that clears that up.

I totally agree with your comments. In retrospect, had I being a little more informed at the time of installation I would have got the WC unit.

My 927 has been playing up, it eats batteries every 6 months and says low battery even with new ones sometimes. If i'm going to replace it i might as well get the new Vaillant one which is reputed to have better user interface than the older VRC units.

I also find the TPI control with the honeywell, I seem to get bursts of around 1 minute boiler runs once the house is warmed up. The CM927 gets to it minimum call time of 1 in ten minutes.

The CM927 calls for heat when the 831 is still in anti-cycle/pump over-run, (i have increased one of them from factory to try to compensate cant remember which to hand). I just feel this could be improved upon with the Vaillant controller.

Paul

 

[processpaul]

I'm not looking for payback on a new controller, just more overall efficiency and the Vaillant would be the best option irrespective of the cost now.

 

[ALEC1]

I replaced a honeywell thermostat with a vrc 430 with a system boilers, and the savings were well over 10%, more like 15%. I have heard claims of 20% from another client where I upgraded the controls....

In both these cases these were fitted after the boiler..

But you do have to engage with the controls to optimise the system...

 

[simond]

By the last comment he means 'constantly refer to the manual'.

'Willfully obtuse' would be my description of the user manual.

Alec has just enrolled himself on a course with Vaillant to learn about their controls, I'm told.

Make of that what you will.

 

[ALEC1]

CPD (Continuous Professional Development) is the way I see training...I have over 100 vaillants out there with their "modulating controls".

Even though I am pretty well versed with them, there is always somethng I can learn..

And I agree about the english in the manuals...

 

[David937]

Tony

Thanks for your reply, I see RF (should have thought of that!), that clears that up.

I totally agree with your comments. In retrospect, had I being a little more informed at the time of installation I would have got the WC unit.

My 927 has been playing up, it eats batteries every 6 months and says low battery even with new ones sometimes. If i'm going to replace it i might as well get the new Vaillant one which is reputed to have better user interface than the older VRC units.

I also find the TPI control with the honeywell, I seem to get bursts of around 1 minute boiler runs once the house is warmed up. The CM927 gets to it minimum call time of 1 in ten minutes.

The CM927 calls for heat when the 831 is still in anti-cycle/pump over-run, (i have increased one of them from factory to try to compensate cant remember which to hand). I just feel this could be improved upon with the Vaillant controller.

Paul

FWIW, we replaced our CM927 last September with the VRC430f, I am pleased to say it works very well and I like how the controller talks to the boiler. After making a few adjustments when it was new such as setting the correct heating curve and the control strategy, it is simply left alone to do what it has to do. The only changes made to the parameters on the boiler are the pump over run time and the range rating setting. Everything else such as anti-cycle control etc has been left at the factory setting. I can relate to what you mean when the CM927 calls for heat when it is in anti cycle mode and can also relate to the short cycles etc.

 

[ALEC1]

somewhere there is an EU document that says that programmable thermostats such as the CM series are not compatible with condensing boilers...

Put technically the modulating thermostats call for short burst of heat 30 seconds, and of course the boilers take longer to ramp up, and have their own anticycling logic...

 

[Agile]

I dont follow that Alex.

I thought the CM 927 was a basic on-off stat which calls for heat until it is satisfied?

Tony

 

[Agile]

Alec has just enrolled himself on a course with Vaillant to learn about their controls, I'm told.

I did ask Alex if I would be able to come to that course but he has not responded.

Perhaps its only for members of a secret society?

Tony