Vaillant v-smart advice needed

YouCountthePennies

We have the Vaillant v-smart app - what schedules have you set? It is very complicated I have no real idea how to best use it efficiently or read it.

 There are 2 programmes comfort or eco.  Hot water release is enabled in on these.

I know how to set the temperature and a schedule but have no idea how to make up my own programme and get it right.

We have a tank and a Vaillant boiler. It’s a pressurised system.  I know it’s smart but I’m sure we could use it more efficiently.  The heating is on all the time but with a lower temperature in the day and at night.  The hot water is now off at night. 

 The house is 30s solid wall so quite cold.

 Can anyone help with settings? 

ThisIsWeird

Hi, yctp.
A couple of essential truisms; 1) it is cheaper to heat your house only when you need it, rather than to have it warm 24hrs. 2) You need to be adequately warm.
Older - generally less well insulated - houses like yours will require more energy - and take longer - to get up to the required temp, so it'll likely make sense to not have it drop too much in temp overnight and other 'not needed' times, as it could then take too long to get the required temp back up for when it is needed. Also, too-large a temp swing can exacerbate other issues such as condensation forming when the temp drops 'too' much.

So, all that likely means a compromise between these first two points.

I'm not familiar with the V-Smart, but suspect it's cleverer than my Hive. My Hive just comes on at my programmed temp at the time I want - that's pretty much it. I suspect your system will tweak what you ask of it to provide this as effectively as possible.

For instance, my Hive calls for 18.5oC at 5.30, in anticipation of that temp being needed at 6.30. On mild overnighters, that's easily done; on cold nights, it doesn't manage.

Your V will likely ensure it gets there by changing the starting time in order to do so. It'll 'learn' to do this, so as the weather improves, it'll automatically reduce the early start times to suit. That's a guess. (A quick look at a vid on YouTube suggests that it does 'learn').

So, you just need to choose what temps you want at what times, and then let the V decide when to fire up the boiler to achieve these. Or, do you need to tell the V when to come on in advance? Is that one of the Qs you are uncertain about?

As for suitable temps, that's obviously your call, but I'd suggest that overnighters should neither be too cold nor too warm - the first can increase condie, and the latter will simply cost money. 

As soon as the heating goes off at night, following what is presumably the warmest house setting of 'evenings', the ability of the air to hold on to dissolved water will tumble, and some will almost certainly look for the coldest surfaces to condense out on - at least it will if you do not ventilate the house properly. 

Q - do you have 'running' windows in the morning? If you do, there are two solutions - one is to keep the temp high so the air is warm enough to hold on to it - which will obviously be very costly - and the other is to ventilate your house properly, especially overnight, in order to allow the excess moisture to be driven off. That will be cooler, but a lot cheaper.

So, you should first decide on some figures; what temps do you want, and at what times.

I have a late '30s house, and it's ok once you get it up to temp, but it can take some time to get there. So, my current overnight temp is set to 15oC. That seems a good compromise for my house; it doesn't get too cold, and it's actually easy for the CH to maintain - it tends to only pop on for short periods to maintain this. In addition, tho', I have the heating fully off in the bedroom overnight, and with windows on 'vent', so we only have condie forming on the glass in the coldest overnighters - just a few times so far this winter (mopped up the following morns).

During the day, I have the 'min' temp set to 18oC if other folk are at home, or 17.5 if just myself. By 'min' I mean if folk are at home but not sitting on their butts. If 'cosy' home is needed, then it'll be set to whatevs is needed, 19, 20, whatever. By having the day temp at a min 17.5oC, it means it'll get back up to 'living' temps easily. Again, it doesn't take much to keep the house at 17.5 during the day - the Hive gives me a record of 'ons' - but turning this min up to 18 makes a significant difference, so I don't as it isn't needed when I'm on my own.

So, have you written out a list of temps and the times you want them? That's your starting point. Then decide on overnight temps.

Albermarle

I have a late '30s house, and it's ok once you get it up to temp, but it can take some time to get there. So, my current overnight temp is set to 15oC. That seems a good compromise for my house; it doesn't get too cold, and it's actually easy for the CH to maintain - it tends to only pop on for short periods to maintain this. 

Just as another example. I have a solid brick '20s house.
I leave the heating off all night. So from 21.30 to 05.30 ( if it is icy) . It only seems to start feeling cool after around 23.00 and is warm enough in most rooms by 07.00/07.30.
As the heating is normally on all day, the residual heat seems to stop it getting too cold even in the middle of the night.
However if we go away for a couple of nights and just leave the heating on for a couple of hours a day, it takes hours to get warm again.

FreeBear

Albermarle said:

I have a late '30s house, and it's ok once you get it up to temp, but it can take some time to get there. So, my current overnight temp is set to 15oC. That seems a good compromise for my house; it doesn't get too cold, and it's actually easy for the CH to maintain - it tends to only pop on for short periods to maintain this. 

Just as another example. I have a solid brick '20s house.
I leave the heating off all night. So from 21.30 to 05.30 ( if it is icy) . It only seems to start feeling cool after around 23.00 and is warm enough in most rooms by 07.00/07.30.
As the heating is normally on all day, the residual heat seems to stop it getting too cold even in the middle of the night.

Late 1920s semi here, half cavity, half solid brick. Heating is "on" 24/7 at the moment. Thermostat set to 16°C overnight, and between 08:00 & 22:30, 18.5°C. So far this winter, the boiler hasn't fired up in the middle of the night.. 

Currently using 20-30kWh of gas - Did hit 45kWh earlier in the month. Having a decent level of loft insulation and new DG windows & doors has really helped to reduce heating costs. Internal wall insulation also helps (still have a couple of rooms to do), but the IWI isn't making as much difference as one might expect. What it does do though, is keep the surface temperature above dew point and eliminates condensation.

If a property is cold and proving difficult to get up to a respectable temperature, the OP needs to either insulate & draught proof the heck out of the place or fit larger radiators. Or better still, a combination of both so that the house is heat pump ready for the day when gas boilers are no longer available.