Vaillant VR71, SensoComfort and NetSensor Gateway initial set up

[thebaldfox]

Just had boiler controller upgraded:

Existing Ecotec 637 plus.
We installed a VR71 / SensoComfort VRC720f / NetSensor Gateway

Everything appears to be working. Tech support recommended system diagram 2 (we have single heating and HW circuits). We also added a second circulation pump. They recommended we use curve 2.6, and to set the mode to "expanded". Didn't use the VR11, nor 2 of the VR10 probes.

I've had a quick look and can see the timing section where we can tweak the on/off times, but is there anything else that we should be doing in terms of set up for modulation? The app isn't the greatest, but the house appears warm.

Will there be a settling in period where the system will learn how thermally insulated/uninsulated we are and make calculations accordingly etc? Is there anything else I need to be mindful of?

thx

 

[ScottishGasMan]

Under the intaller level, where you have circuit1 (where you set heat curve) you will have installation menu, you can set the "Adaptive Heat Curve" to Activated. This will then monitor how quick the place heats and how often it overshoots the target temperature and can adjust the heat curve from 2.6 automatically if there is scope to lower it, as this will result in lower flow temperatures where you can manage it.

 

[thebaldfox]

Under the intaller level, where you have circuit1 (where you set heat curve) you will have installation menu, you can set the "Adaptive Heat Curve" to Activated. This will then monitor how quick the place heats and how often it overshoots the target temperature and can adjust the heat curve from 2.6 automatically if there is scope to lower it, as this will result in lower flow temperatures where you can manage it.

Hi @ScottishGasMan Thank you for your reply! I checked this morning on the menu. I couldn't find the setting you're referring to. Is it the setting under Room temp. mod? I currently have that set to Expanded as per Vaillant's tech support. Should I switch this to Active or am I missing another setting?

 

[ScottishGasMan]

Sorry wasnt very clear, your in the circuit menu, press back button to come one level back, and scroll up to top where "installation" is, tick into that and then you will have adaptive heat curve in there.

While were on the subject, your pic shows set-back mode at eco, generally, with weather compensated systems we want to use the set back, so I'd change it from eco to normal, and then you have a minimum temperature that the house would drop to, makes reheating quicker and uses lower temps as its not lifting the house from like 10 degrees all the way up to 20 every time it kicks in.

The actual set back temp (the temp that the thermostat aims for outside your regular heating times) can be set under the control menu, in where youd set your heating times.

 

[ScottishGasMan]

On mine I have set:

Setback temperature 18 degrees (this means outside heating periods the control will bring the boiler on at lower temp to maintain at least 18 degrees in the house at any time) you may want 16 or 17, but I'd personally not go lower than that.

CIRCUIT1 menu:
OT Switch off threshold: (this is the outside temperature when the heating will cut off) you can leave it at 21 and turn heating off in summer manually, I set mine to 16 degrees, so any time its above 16 outside the heating is automatically off, you tend to find 16 or above air temp will only be at times when theres enough solar energy hitting the outside walls to maintain a comfy tempearture in the house during the day anyway, and if it dips in temperature over night the heating will come on at lower flow temp just to keep the chill off.

Setback mode: ECO= No setback, outside of timed heating periods the house will cool down, NORMAL= setback active, so control will maintain the minimum setback outside of timed periods, stops the place getting too cool, and then causing it to take a while to heat back up the next time the heating is on.

Room temp mode: EXPANDED will be the best setting for yourself probably, I use active, but that means the boiler and pump run 24/7 and vary only the flow temp to maintain a constant room temperature, expanded turns heating on and off depending on the room temp and what you have set. Generally for boilers Expanded will be the best method to use. I'm setting my system up to take a heat pump soon so my settings lean more towards whats best for them.

 

[thebaldfox]

This is invaluable thank you. I switched off eco as you said for the set back and also turned on adaptive.

One question, how do you handle the hot water side? We have a fairly large cylinder but it's just the two of us here. We have legionella protection on. What sort of cylinder temps can you get away with?

 

[ScottishGasMan]

I run my cylinder at 50 degrees, with a once a week legionella cycle.

Legionella domestically, from a mains fed cylinder is a very low risk, Legionella dies above 50 degrees, but can take a few hours, over 60 degrees its a couple of minutes, so there's an argument that if the water is being turned over regularly and kept at 50 for a reasonable time then there is no need for legionella protection.

There's no regulation on legionella domestically, the HSE still recommend storing water above 60, but heating anything that will need mixed down for use is inefficient, and efficiency is getting important these days.

Legionella is a threat from water which forms an areosol that can be breathed in, so while that can happen at any outlet, the shower is the biggest risk factor. Most mixer showers have a max tempearture of about 43 degrees, so your shower hose and head is never subject to legionella disinfection by temperature. So it doent matter if the stored water is 40 degrees or 80 degrees, if legionella build up was present in the hose/head it would never be removed by tempearute.

So unless you regularly remove the hose and head and disinfect it, then there is always a "risk" at showers that tends to be ignored, and Im not aware of any death in the uk that has been traced to a domestic legionella outbreak.

If your fit and healthy then I personally wouldnt worry about it, if your older or have any heart/lung conditions, then stick the legionella cycle on once a week, and just be aware the hot water can be scalding hot for the day after the cycle is done.

 

[Deleted member 281264]

Why did you need a VR71 if you only have one heating circuit and one DHW circuit? Surely the wiring centre is not needed.

I'm glad I didn't buy the sensonet gateway. Heard from many people that the app is rubbish.

I like to try and run my system on pure weather compensation (inactive mode) if the system is correctly balanced with TRV's set as limiters then it should be a comfortable and efficient heating system. Using room temp modulation will reduce efficiency and expanded even more I think.

 

[thebaldfox]

Why did you need a VR71 if you only have one heating circuit and one DHW circuit? Surely the wiring centre is not needed.

I'm glad I didn't buy the sensonet gateway. Heard from many people that the app is rubbish.

I like to try and run my system on pure weather compensation (inactive mode) if the system is correctly balanced with TRV's set as limiters then it should be a comfortable and efficient heating system. Using room temp modulation will reduce efficiency and expanded even more I think.

I bought it for the additional expandability in the future. I'll be looking for a loft conversion and a possible extension, so figured this would be the easier route for future expansion.

Additional thoughts on the app is that it's not great, but it is functional, so it's ok. I intend to go down the TRV route at some stage, but for now I'll see how I get on with it.

 

[thebaldfox]

Just as feedback for anyone else interested. It’s been a couple of days since I refined the set up thanks to the helpful instructions above. I just double checked the curve and it’s been moved down to 2.5 automatically from the 2.6 that valiant tech told me to use initially. Now I’m not sure if this is a result of recent weather changes or the system is “learning” the house, but I thought I’d note it. Hot water temps are set to 50 in the cylinder and the taps are still piping hot. If anything, too hot. It comes on for 2.5 hours in the morning and 2 hours in the evening. Wondering if I can reduce those further.

 

[Deleted member 281264]

Maybe you have the adaptive heat curve option set.

Charging your cylinder for 4 hours a day is insane.... totally over kill and a waste of energy. Better of setting it to manual if you got a hot water priority set up

 

[thebaldfox]

Maybe you have the adaptive heat curve option set.

Charging your cylinder for 4 hours a day is insane.... totally over kill and a waste of energy. Better of setting it to manual if you got a hot water priority set up

This was the default set up on the sensocomfort. I didn’t quite follow your recommendation. Can you elaborate please?
How often are you heating your cylinder for?

 

[ScottishGasMan]

Maybe you have the adaptive heat curve option set.

Charging your cylinder for 4 hours a day is insane.... totally over kill and a waste of energy. Better of setting it to manual if you got a hot water priority set up

Manual being on 24/7. How is that less overkill than 4hrs?

If the cylinder heats within the on period it will turn off automatically anyway

 

[Deleted member 281264]

I'm fairly new to the hot water priority system

I just left mine on manual and then it recharges whenever needed giving constant hot water without realising the heating goes off like combi. I set manual cylinder temp to 4

Would you say this is more inefficient?

 

[ScottishGasMan]

For a boiler system it shouldn't really make much difference tbh, modern cylinders are insulated enough to just leave on