VR65/VR66 for HW flow temp control

[fezster]

I have an ecotec plus 438 boiler and I use the SL for both heating zones and DHW.

If I remember correctly, for ebus to fire the boiler you needed to leave the boiler terminals 3+4 bridged (I dont have it bridged and the boiler only fires on the SL).

 

[bwel]

I have an ecotec plus 438 boiler and I use the SL for both heating zones and DHW.

If I remember correctly, for ebus to fire the boiler you needed to leave the boiler terminals 3+4 bridged (I dont have it bridged and the boiler only fires on the SL).

Aha. Many thanks.
Based on how I have it wired now, The DHW fires up with the right hand CYL terminal of the VR65 terminal and No connection from the Nest to the Boiler Switched Live RT (3, 4)

 

[bwel]

I have now added a VRC470 in the Facia of Boiler ecoTec 630.
So the Setup is as others with
- Nest 3rd Gen Theormostats for Heating Circuits - Nests Control Heating Zone Valves and the Boiler Switched Live RT (Terminals 3,4)
- VR65 with Cyl Terminals (Grey, Orange)

Without the VRC470 in the Boiler Facia, all works well, however Once the VRC470 is installed in Boiler Facia, the control of Demostic Hot Water charging is LOST. The VR65 is receiving the DHW Demand voa the Cyl Termsinal (Grey, Orange DHW Zone Valves), but for some reason the Boiler is either not getting the DHW demand signal or the newly installed VRC470 is inhibiting the DHW Charging.

The VRC470 does indicate in the menu that:

System
- Domestic Hot Water - Charged

Also
Domestic Hot Water
- Cylinder - Active
- Cylinder temp target - 70 c
- Cyl Temp curent - 0 c Note: of course VR65 is using Cyl terminals only and not the Cyl Temp Sensor so would not know the actual temp

When I switch the DHW demand On or Off via one of the Nests, I no longer hear a relay switch in the VR65 when the VRC470 is fitted in Boiler facia.

Does anybdy have a similar setup ? what else should I look at ? any Menu or configuration settings on either the Boiler or VRC470 that needs adjusting ?

Again, It all works perfectly including DHW control (at the higher temp than Heating circuit) from the Nest if I remove the VRC470 from the Boiler Facia.

Many thanks

 

[bwel]

I have now added a VRC470 in the Facia of Boiler ecoTec 630.
So the Setup is as others with
- Nest 3rd Gen Theormostats for Heating Circuits - Nests Control Heating Zone Valves and the Boiler Switched Live RT (Terminals 3,4)
- VR65 with Cyl Terminals (Grey, Orange)

Without the VRC470 in the Boiler Facia, all works well, however Once the VRC470 is installed in Boiler Facia, the control of Demostic Hot Water charging is LOST. The VR65 is receiving the DHW Demand voa the Cyl Termsinal (Grey, Orange DHW Zone Valves), but for some reason the Boiler is either not getting the DHW demand signal or the newly installed VRC470 is inhibiting the DHW Charging.

The VRC470 does indicate in the menu that:

System
- Domestic Hot Water - Charged

Also
Domestic Hot Water
- Cylinder - Active
- Cylinder temp target - 70 c
- Cyl Temp curent - 0 c Note: of course VR65 is using Cyl terminals only and not the Cyl Temp Sensor so would not know the actual temp

When I switch the DHW demand On or Off via one of the Nests, I no longer hear a relay switch in the VR65 when the VRC470 is fitted in Boiler facia.

Does anybdy have a similar setup ? what else should I look at ? any Menu or configuration settings on either the Boiler or VRC470 that needs adjusting ?

Again, It all works perfectly including DHW control (at the higher temp than Heating circuit) from the Nest if I remove the VRC470 from the Boiler Facia.

Many thanks

Looks like I have solved it.
For anybody else experiancing this the solution was to Toggle the Settinings under Installer / System / Domestic Hot Water/ Cylinder - Active to Inactive to Active again, then it all works.

To be fair, having the VRC470 in the Facia as oposed to not having it, does not seem to have any benefit, as all the settings via the d. codes directly within the boiler / interface seem to still control all the temperatures (DHW, Heating etc), and the Nests control the rest.

 

[fezster]

Ok glad you solved it.

I was just going to post to check the CYL right hand terminal has 230V in the VR65/66 - that is what instructs the VR65/66 to enter DHW charging mode and boosts the flow temp to 80 degrees.

The advantage of the VRC470f (in my case) is the weather compensation with the outside temperature sensor. This allows the flow temps to be modulated, whilst still using the Nest's to control firing of the boiler and the VR65/66 to enter DHW mode.

 

[bwel]

Ok glad you solved it.

I was just going to post to check the CYL right hand terminal has 230V in the VR65/66 - that is what instructs the VR65/66 to enter DHW charging mode and boosts the flow temp to 80 degrees.

The advantage of the VRC470f (in my case) is the weather compensation with the outside temperature sensor. This allows the flow temps to be modulated, whilst still using the Nest's to control firing of the boiler and the VR65/66 to enter DHW mode.

Many thanks,
I’ve been operating the Weather Comp even without the VRC470, all you need is the outside Temp Sensor that wires into the Boiler edge connector and you can set the Heating Curve within the relevant boiler d. Code.

I had originally been hoping that the VRC470 may have been able to provide full control menus for the Boiler d. Codes and provide a full status summary of the boiler operation. I should have read the manual before picking it up of eBay.


Really I can’t see any advantage of using the VRC470 in addition to weather comp that’s already inbuilt to the ecoTec boilers when you just wire on the outside temp sensor.

 

[woodbutcher56]

Many thanks,
I’ve been operating the Weather Comp even without the VRC470, all you need is the outside Temp Sensor that wires into the Boiler edge connector and you can set the Heating Curve within the relevant boiler d. Code.

I had originally been hoping that the VRC470 may have been able to provide full control menus for the Boiler d. Codes and provide a full status summary of the boiler operation. I should have read the manual before picking it up of eBay.


Really I can’t see any advantage of using the VRC470 in addition to weather comp that’s already inbuilt to the ecoTec boilers when you just wire on the outside temp sensor.

I've ordered a VR65 and a VRC693 from the bay of fleas, having read these helpful posts. The weather compensator has a connection block included, which I assume should be fitted to the boiler PCB position X41. How do you set up the heating curve with the boiler d. code please? I have an ecoTEC plus 618 and no VRC470 or equivalent.

 

[bwel]

I've ordered a VR65 and a VRC693 from the bay of fleas, having read these helpful posts. The weather compensator has a connection block included, which I assume should be fitted to the boiler PCB position X41. How do you set up the heating curve with the boiler d. code please? I have an ecoTEC plus 618 and no VRC470 or equivalent.

I asked this of Vaillant Tech mid last year. This is what they advised.

“If you wish to add weather compensation to your system then you could install a VRC 693 wired weather sensor and then connect it to X41 on the main PCB.

You would then be able to adjust the heat curve in the diagnostic menu of the boiler using D.043”


“The D.043 code won't appear until the X41 connection is added to the appliances PCB.

Once connected you will be able to adjust the heat curve in D.043. “

Hope that helps.

 

[woodbutcher56]

Thanks so much for that, I'll post any results here later.

 

[woodbutcher56]

I asked this of Vaillant Tech mid last year. This is what they advised.

“If you wish to add weather compensation to your system then you could install a VRC 693 wired weather sensor and then connect it to X41 on the main PCB.

You would then be able to adjust the heat curve in the diagnostic menu of the boiler using D.043”


“The D.043 code won't appear until the X41 connection is added to the appliances PCB.

Once connected you will be able to adjust the heat curve in D.043. “

Hope that helps.

It looks like my Ecotec 618 Plus is too old to have the D.043 register, being installed in 2008. No reference to it in my manual, I do have D.047 which reads the outside temperature from the VRC 693, and the VR65 is working to give the DHW override, so I guess I'll need to find a VRC 470 to make weather compensation work. Having lifted floorboards from front to back of the house, then drilled through some awkward brickwork to get the cable to the boiler, I'm fairly committed to this. Meanwhile I can play with the flow temps and range rating manually, a chap needs a hobby. Thanks to all here, I had given up on this as a possibility without spending silly money on a vintage boiler.

 

[bwel]

If you boiler is too old get the heating curve by d.043, it may also be that it’s too old to use the VRC470. I originally purchased a VRC430 thinking that would be ok to fit within the Boiler Facia to control the Heating Curve, but then found my boiler was too new (2017 I think) and so found the fitting would not take the Horizontal Pins (of VRC430) but needed the Vertical pins (of VRC470).

I would advise you to remove the boiler Facia blanking plate first to check what you have there. It just pops out from a couple of retaining barbs in the plastic. Ie you don’t need to drop down the whole PCB control panel.

 

[woodbutcher56]

Thanks again, you're right it's horizontal pins. My manual mentions a VRC400, so it looks like I need one of the earlier models. Do you still have your VRC430 by any chance?

 

[bwel]

£15 plus postage if you would like it ?

 

[woodbutcher56]

Absolutely. Could you message me on WhatsApp? 07477667206

 

[woodbutcher56]

Apologies for not updating this sooner, but the weather has been unhelpfully warm for setting up weather compensation. Thanks to bwel, I now have a VRC 470 to enable my VR65 and VRC693 to work. In a well insulated 30s semi, pretty airtight with heat recovery ventilation, the Ecotec Plus 618 is overkill, even rated down to 7kw for the heating, so the anti cycling function can mean very little heat unless I set a target temperature of 28 degrees in the VRC470, for an actual room temperature of 20 controlled by a separate thermostat on the switched live S plan controls. I'm not convinced we'll save a lot on our gas bill, but hopefully after some colder weather and more tweaking, a more even and comfortable temperature will be acheivable without much human intervention day to day. I'll also gain a much better idea of requirements for a heat pump if/when the boiler expires, probably between 6 and 10kw modulating down to 1 to 2kw.