Intergrating 5070THPR with Vailant ecotec boiler(UK)

Hello

This is my first post so I will try to be detailed.

I have a Vaillant ecotec plus 630 boiler and was wondering how to intergrate a 5070THPR to control the system

I have attached a screen shot of the wiring diagram.


I called Vaillant for some assistance but I dont think their advice was correct as they said I should connect the thermostat to the 240/240 connections which doesn't make sense.

Can you help me out please?

p.s I will not be connecting any of this myself but I have to explain it to the electrician/plumber who is totally dazed and confused about c-bus

 

Georgee

I'm no expert either! That makes at least 2 of us now... so caveats apply to what follows.

It looks like a combi boiler, so I take it that you want the CBus system to schedule the "On" and "Off" periods for the central heating and that you want to use the CBus Thermostat to tell the combi boiler when to put out heat to the radiators.

If so, then I am fairly certain that the relay that NickD refers to needs to go between terminals 3 and 4 (after removing the wire link). Closure of the relay will call for heat, and opening will stop the flow of heat to the rads.

You'll be switching 240 V (but very little current) with the relay so make sure it's rated for this. You'll also need to program the time clock of the boiler (if fitted) to run the CH all the time in order that the CH is enabled 24/7. The CBus can then call for heat when it sees fit. Your plumber should also avoid putting TRVs in the system because otherwise the CBus stat could end up calling for heat when there's none available from the TRVs.

Hope this helps.

Phil

 

Hello Guys

The boiler is condensing system boiler with a mega flow.

Only require on/off function. I really am just trying to integrate the heating in to cbus but this seems to be far harder than I thought. my plans of having cbus for home automation and comfort for an alarm & ha isn't going as smooth as I thought.

I thought the relay would connect to 7/8/9 because those are the 24v connectors for room stats.


I currently have a wireless drayton digistat room stat which looks like it connects to volt free contacts as well as the 230v according to the diagram.

I will have to wait to the plumb comes and see how it is all connected at the moment.

I didn't relay want to purchase another relay

Thanks for the advice.... so it looks like a definite maybe but that s better than a no.

on a side note all the rads have tvr already as the previous plumber advised.

 

If you've already got this set up with a Drayton digistat then it will be easy to implement all the functions of the digistat through CBus.

The digistat's connections "1" and "3" will be wired to the boiler. These terminals on the boiler are where the CBus relay needs to go across. (I would be surprised if it did not connect to 3 and 4 on the boiler board). The digistat receiver also requires its own power and will therefore also be connected to the boiler supply. The CBus system will not require this.

The boiler board will put out 240 Volts AC across terminals 3 and 4 so the relay integral to the CBus stat you describe will NOT do. You'll have to use another CBus relay.

As the 5070THPR is at the same time overkill in zones and relays, whilst being underrated in term of switchable volts, you'd be better off sending this back and replacing it with a 5070THB. You can then spend the refunded money (plus a bit extra!) on a 5101R to do the switching. (If you have got a spare mains-rated relay channel somewhere you could just use this).

If you can't get your money back, your other option is to have the 5070THPR's relay drive a second relay that can handle the mains. You'll need a power supply for this.

I have had a scoot around the web to find out what the 24 Volt contacts are provided for. In France they have a modulating room stat. The documents are here. (Though they're in French) http://www.vaillant.fr/stepone2/dat...hermostats-et-regulation_brochure_2007_01.pdf

Page 6 describes them as "Modulating thermostats. These thermostats are particularly recommended for our range of modulating wall-hung boilers. In effect the ambient temperature thermostat gives a signal to the boiler when the desired temperature is near to being attained."

In the absence of further information (from Vaillant) about exactly how these work, I can't see an easy way of using these 24 volt termianls and suspect you'll have to use the 240 Volt switching I've described above.

Good Luck

Phil

 

thanks Phil, you've been a great help.

 

I'm just about to do exactly the same...

Mine's an EcoTec Pro 24. I'm fairly happy about how I'm going to approach this... the main control point is indeed terminals 3 and 4 on the boiler control board (where the link was) - I am going to put a CBUS relay channel across that, and then add a 5070THBPGWE CBUS T-stat for the user control...

I do however want to leave the onboard boiler controls in place, - both for failback (not that CBUS ever fails!) - and to keep the British Gas engineers happy when they come to do my annual service... (the fitter already started shaking his head as he was installing the onboard controls, and muttering about voiding the warranty) - I had thought that what I needed to do was to just set the vailant T-stat (I have the wireless one) right down as low as possible (so it never calls for heat), and also to "de-program" the onboard timeclock (I have the TimeSwitch130) so that it also never calls for heat... - my thinking being that by bridging 3 & 4 with my CBUS relay, that instructs the boiler to provide heating and the onlboard controls would never interfere or "override" what state CBUS says the boiler should be in - because if the onboard controls were set to call for heat, CBUS would not be able to override that and set the heating off - those terminals are just a simple Normally-Open switch, and if *anything* closes the switch, the boiler fires the heating... (that's how I understand it).

Where I've just become less certain is how the timeclock connects into the demand circuit, - it's a snap in module that requires no wiring, so does not get connected in to terminals 3 & 4... - I can't tell from the documentation where on the board it *does* connect.. - I'd be inclined to suspect it might use the X40 accessory connection?.... Why this matters is to deduce what the behaviour will be in terms of what input the timeclock has to the demand circuit in relation to terminals 3 & 4 - I.E....

Is it necessary for both the timeclock to be calling for head AND 3 & 4 to to be calling for heat in order for the heating to come on? - in this case I'd need to set the override switch on the timeclock to constant...

No doubt I can figure this out with a bit of trial & error, but if anyone's worked this out before, some info would always be appreciated...

Cheers.

Paul G.

 

Yes. (IF It's the time when people are in the house AND the room is cold THEN heat=ON)

So don't set the onboard timeclock so that it also never calls for heat (as you suggest earlier).

Yes. That should sort it. You can then do the timer functions in CBus and you won't need to mess up the onboard boiler controls.

Personally I would just remove the Vaillant T-Stat. Otherwise there's the chance that guests will fiddle with it and cause conflicts between CBus and the Vaillant Stat. (Though I suppose if it's a wireless job, you can just take the batteries out and hide the thing away).

 

That makes sense.

Appreciate that, - and yes it was my intention to take the batteries out of the transmitter unit & put it away for safekeeping, only to come out each year when the engineers come to do the annual service.

Cheers.

Paul G.

 

This'll work?...

This is my intended method to connect / control the heating demand from CBUS... (see graphic). The top "leg" of that is the original Vaillant T-stat circuit..

I will disable the original Vaillant T-stat (it's wireless, so I'll remove the batteries & put it away in a cupboard).

I will set the timeclock override to constant, since it's connected into the demand circuit independently from points 3 & 4 which are in truth just the external thermostat connections.. as it's on constant, the only remaining demand switching mechanism are those t-stat terminals...

Then, as I see it, the boiler will only fire for heating when the CBUS relay closes & shorts points 3 & 4...

The CBUS T-stat provides control input to the system, - both manual user setting, and from other CBUS units.

I will implement all scheduling of on/off times in Comfort. Comfort will exercise control by signalling to the CBUS t-stat which will do the actual switching.. I need to firm up on my understanding of exactly how this is to be programmed/enacted, but as I understand it currently I can do any of:
1) send ON/OFF messages to the T-Stat itself? - does T-stat:ON = Heating ON & vice versa?
2) or I could utilise the setback function, this may not provide a sufficient level of control though? - need to understand the implications of setback a bit more...
3) Send actual temperature setpoint commands to the T-Stat. (Wiser may be required to implement this?)

Make sense? - anyone spot any flaws in my thinking?

I will almost certainly be back once I've got the CBUS thermostat to play with, to seek help in getting the programming right from the options above..

Paul G.

 

Wiring looks good to me. Why don't you put in a DPST switch to select between Cbus and "Engineer is visting mode"? See diagram.

I can't comment on programming the CBus stats. I'm sure you'll get lots of help when you need it.

Phil

 

I'd thought of that...

That was in fact included in my original thoughts / design, but I dropped it out just for the sake of simplicity... - I think when I was originally mulling over the various options I considered so many possible variations that I ended up confusing myself!

After which I just decided that, as in most things in life, the KISS principle is a valuable maxim...

Perhaps when I come to actually wire it up I'll sort out some kind of manual switching mechanism...

P.

 

Now I remember...

One of the other reasons I did away with the "changeover" switch was because of the way the onboard timer connects into the circuit. Because it's (electrically at least) like indicated in the picture, - the timeclock would be unaffected by such a switch, and this might be confusing... - If I could get the wiring such that perhaps a DPDT switch also isolated that timer, then it would be more worthwhile...

As it is, it just selects between the onboard or the CBUS *thermostat*, and flicking the switch over doesn't actually effect a complete change from "default controls" to CBUS controls - because in either position the setting of the timer would still be effective (i.e it needs to remain on constant to allow CBUS to fire the boiler). If someone were to alter the position of the override switch on the timer, then CBUS would not be able to call for heat outside of the timed ON periods programmed into that onboard timer... - Thus having a switch labelled "CBUS control" and/or "Onboard control" wouls be a little misleading IMHO... (the blue dotted line represents the boiler casing).

Paul G.

 

OK, ready to start...

Working through the installation slowly... - I've now got the t-stat installed on the CBUS network, addressed, and changed the application to Lighting (so I can utilise an existing spare relay channel)

Errrr... what next... - I took a look through all the tabs in toolkit, and came away complete confused.... I have made a start on reading the help pages in toolkit regarding the various options, but there are a lot of them, so that is going to take some time...

My installation requirements must be just about the simplest imaginable: I need to use just *one* relay to signal heat demand to a combi boiler... relay closed=boiler fires up, heating comes on... relay open=boiler shuts off, heating goes off... - simples...

Is there anywhere a simplified set of instructions for how to program the unit for this scenario?....

I've already created a new group called "Boiler control" & added my spare relay channel to it... I've still actually to wire it up to the boiler demand terminals yet, but that I can complete quickly & easily, - I'm more concerned about figuring out the programming, so if anyone can offer advice re a simplified set of options to select/configure, that would be *much* appreciated!

Cheers.

Paul G.

 

Am I getting close?

From looking at the myriad options available in toolkit, it seems to me that none of the "predefined installations" are suitable... - the "conventional single stage heat/cool USA system" sort of comes close, - but I don't have or need the "cool" part.... So ignoring the predefined options, and looking at configuring it manually, from the plant options, it seems logical that most appropriate selection from the plant equipment list is "Furnace (gas, oil, electric)" - and then in the options for operating type enable only the "heat" option (de-selecting the "vent" option) - sound about right so far?...

Then in the "heating groups" - the only button left enabled as a result of the previous settings... I've selected my "boiler control" group (the relay going to the boiler demand circuit) as the "stage 1 group" - leaving all other groups on that page <unused>...

That's as far as I've got to date.... anyone care to comment on my assumptions / logic thus far?...

TIA

Paul G.

 

Picking a default configuration and then tweaking it to suit your plant is definitely the right way to go. You could have also started with a Basic Hydronic system too, and just changed the plant type on the Plant and Zone tabs to Furnace.

You're definitely going in the right direction. You may need to tweak the Cycle Limiting values on the plant tab so that the Thermostat operates the boiler within the limits for your boiler.

After selecting of the preconfigured USA modes, don't forget to change the default Temperature Units on the User Interface tab back to Celsius.

 

More questions...

Thinking about the predefined installations.... - where do they come from, and are only those supplied with toolkit available for use? - strikes me it might be useful to have the ability to setup custom configurations & save them as an installation file.... further to that, we could then have a community exchange of installation files to make this whole affair a lot simpler!

Paul G.

 

Good thoughts, good thoughts... although it's been our experience in the past that people are less than willing to share such things with others, be that due to simply not bothering to share or otherwise. Just look how little logic is shared in the Community Logic Code Examples section of the forum. After all, the ability to know and understand this stuff is often connected to people's paid jobs.

 

Yet more questions

Could I use the multi-stage options to also control some additional heaters around the house? - say some portable electric fan heaters controlled via CBUS relays? - so I could for example allow for additional boost heating on really cold days?

If I configure the CH Boiler as stage 1, using my "Boiler control" group, and configure another group on stage 2 (say "boost heaters") - with the additional electric heaters controlled by that group, would this then bring on the CH Boiler initially, and then subsequently bring on those additional heaters if the temperature doesn't come up to the setpoint in a timely manner? - that would be an intriguing possibility, since I sort of do this already for rapid heat boost in some locations at certain times. Obviously I do this manually just now, but to have it automated by the same t-stat would be pretty attractive...

TIA

Paul G.