Questions about Vaillant ecoTEC Plus 837

[verduijn]

We have a VRC430 Weather Compensator control panel installed on our Vaillant ecoTEC Plus 837 boiler and also have a VR81 remote control unit installed in the living room.

1. What is the relationship and interaction between the programmed times for heating and hot water, and the two big control dials on the left handside of the boiler control panel? For example, what temperature does the hot water go to if the time programme dictates 52 degrees, but the temperature control dial on the left is set to, say, 45 degrees? Similarly for the heating: the heating dial on the left is turned to the lowest setting (30 degrees) and the time programme for heating is set to, say 18 degrees. Which setting takes precedent?

2. In relation to the question above, the radiators do not start heating up until the bottom-left dial is turned up, even though the target temperatures on both the time programme and remote control unit have been set to well above the actual room temperature. What's going on?

3. Section 4.3.3 in the user manual for the VRC 430 Weather Compensator states that the display should return from the basic display to the default display after 5 minutes or by clicking either dial. This does not happen. In fact, I've never seen the default display. Can you clarify?

4. Should the room temperature control (Menu C8 - HC1 parameters) be set to 'none', 'modulating' or 'thermostat'?

5. In menu A5 ("Installation Assistant Module Test Menu") there is an option for Heat Source Choice, which can be set to either 'OFF' or '50 degrees'. What does this mean and what value should I select?

6. The heating is set to automatically go on at 15 degrees, but it seems to kick in when the outside temperature falls below 15 rather than the inside temperature. (I have two sensors). Could they be connected incorrectly? What's going on?

 

[David937]

If you have the VRC430 the CH dial on the boiler should be set to max.

 

[croydoncorgi]

Unfortunately, Step 1 is Read the Fine Manual!

You're asking a lot of questions that ARE answered in there - eg. the Install Assistant Test function set to 50 will make the Heat Source (ie. the boiler) fire up and run to 50, but only for test purposes, to make sure everything is working and communicating.

The water temperature thing is complicated. In particular, IF you have a water-temperature sensor on your cylinder (ie. NOT a thermostat), the water-temperature control on the front of the boiler actually works as such. If instead you've got a thermostat, that control does nothing on anything except a combi version of the Ecotec. AND the sensor needs (I think still) to be plugged into a connector in the boiler, not connected to the VR61 / VR65 wiring centre (assuming you have one).

C8 -HC1 modulating or thermostat defines how the room controller will work: I THINK!, as an on/off thermostat or modulating the boiler up/down depending on the room temperature - colder room = hotter Flow setpoint. None means that the VRC 430 itself will not use its internal temperature sensor and will behave as if it was stuck in the front of the Ecotec.

If the heating is only responding to the outside sensor, first thing to check that you haven't set C8-HC1 to 'none'!

(About the only) nice thing about Ebus is that once connected and communicating, it CANNOT be 'incorrectly connected'.

 

[Agile]

you seem to be posting the same set of questions on different forums.

I dont really see the need for that as the same experts read most of the forums.

 

[kevplumb]

would that be the same expert that posts on here then