Smart thermostat

[cdbe]

I get what you're saying, but I don't want to hand control of my heating to an algorithm - unless it can understand that we heat the house on a budget and are prepared to forgo it being nice and toasty for when we get home because we're generally pretty active cooking etc for the first hour so although we arrive at 5 the heating doesn't come on till 6. Our default setting is heating off whereas these systems it seems to be on by default and it'll turn it down a bit if it thinks it'll get too hot.

I think for Eric his struggles to optimise it all make his hobby of "man Vs machine" more interesting!

Regards the heat switch - the point is that I suspect the hub won't provide an output (eg to operate my valve) without a signal from a stat, an electric rad doesn't require external thermostat control - I guess I'll find out when I get the thing.

 

[Mister Banks]

I get what you're saying, but I don't want to hand control of my heating to an algorithm - unless it can understand that we heat the house on a budget and are prepared to forgo it being nice and toasty for when we get home because we're generally pretty active cooking etc for the first hour so although we arrive at 5 the heating doesn't come on till 6. Our default setting is heating off whereas these systems it seems to be on by default and it'll turn it down a bit if it thinks it'll get too hot.

I think for Eric his struggles to optimise it all make his hobby of "man Vs machine" more interesting!

Regards the heat switch - the point is that I suspect the hub won't provide an output (eg to operate my valve) without a signal from a stat, an electric rad doesn't require external thermostat control - I guess I'll find out when I get the thing.

The heat switch will not work without a room thermostat, you will be wasting your money.

The Wiser system can be programmed however you want so if you don’t want heating on until 18:00 then set the heating to a suitable temperature at 18:00. It is pretty flexible once you understand the concept of temperatures and setback temperatures.

 

[ericmark]

I have set up heating in three homes, the first worked from the word go, so did very little to it, other than change the time switch and thermostat, for a programmable thermostat.

Second home was my parents, and the problem was to switch the boiler on/off at the right time. I found that the cure was to fit the hall radiator with a TRV, and set the TRV to reduce flow before it hit the thermostat setting, not ideal, but it worked.

In this house, the heating was a mess, to turn it on I had to go outside down a set of steps and plug in the pump. One boiler served two dwelling, so it is a bit complex. However, the problem is, as with my parent's house, was turning boiler on/off. Method was multi linked thermostats, and also some unlinked TRV heads.

I think for Eric his struggles to optimise it all make his hobby of "man Vs machine" more interesting!

Likely yes, when all worked, never considered doing anything, only when it didn't work did I spend time and energy to work out why.

@ericmark has issues with his heating because he has multiple different systems that don’t integrate with each other.

That is a bit of a problem, mainly caused because manufacturers lied. Had the Nest Gen 3 worked with Energenie as the adverts said, I would have not needed to change the system.

With what I have now, the problem is radiators on outside walls. But this is a minor problem, and is only a problem in autumn and spring, in winter it is not a problem.

 

[cdbe]

I'm still toying with this. I've got the 2 channel hub and stat but haven't fitted yet as I think best to tidy up current wiring arrangements:

Just a few questions in the meantime - firstly, if I'm coming round to the idea of smart TRV's in the 4 upstairs bedrooms (I actually thought you had to change the entire valve, not just swap the head! so that's easier, and I can delete the 2 port valve from the system) but I keep the existing open ground floor as a single zone with the wiser stat and existing manual TRVs - can I (out of interest) just have a single bedroom radiator running or will it not work if the wall stat downstairs isn't calling for heat?

I'm thinking, if we're on holiday and my eldest, who lives in his bedroom 23 hours a day, wanted just his rad on, would it do this? And if it did, would it cause a problem for my old 15kw boiler?

Secondly, from an aesthetic point does the hub need to be readily accessible - I'd prefer it in the cupboard rather than onto the wall above it?

 

[ericmark]

I watched a video where he claims there is a problem running a boiler under its minium output, but not had a problem myself. Think my boiler is around 20 kW fixed output, and there is no way any single room could use all that, but never been a problem, it just settles into a mark/space ratio, and it seems minium burn time is around 15 minutes, not sure if that is economical, but it works OK.

It really does not matter if the TRV head is pure mechanical, or non-linked electronic, at some point they will all close. However, many boilers have anti-cycling software, the idea is if the water returns hot in a very short time, it will increase the time between trying to fire up, and if the time is very long decrease again. Exactly how the algorithms work with be down to each manufacturer, but if the space in the mark/space ratio becomes too long, then it is possible the room will cool, but the boiler will not fire.

But with my own house, I want in the day, living room, kitchen hall and toilet/shower room warm. And overnight two bedrooms, bathroom and landing warm. So it is never just one room. The temperatures may vary. Hall, landing, and kitchen happy at 18ºC, where living room more like 21ºC. And the craft room, office, dinning room, and the 4 rooms in the flat under main house may be set to around 10ºC, but they are not turned completely off.

So not had a problem with boiler short cycling. The modern boiler is designed to work with TRV's, so I am sure most have an algorithm able to work with just one TRV fully open.

 

[cdbe]

Mines not a modern boiler with any software, but there is a bypass valve on the heating system and there are two towel rails which I think are part of the circuit before it gets to the 2 port valves (so always on) - I don't think it will harm the boiler, just not be very efficient.

I can't figure out whether a smart TRV will open if the room stat isn't calling for heat - maybe the "boost" function will allow this?

 

[ericmark]

I can't figure out whether a smart TRV will open if the room stat isn't calling for heat - maybe the "boost" function will allow this?

Back to what is "Smart" but my cheap (£15 in 2019) eQ-3 heads open and close independent of boiler, and have at 12:00 midday an exercise function where they fully open, fully close, and return to setting to exercise the valve so it will not stick during summer months.

The more expensive Energenie and Kasa TRV heads, both can be linked to a wall thermostat, but I don't have the wall thermostat to match the heads, so these are also independent of the boiler running or not, and also have the exercise function.

The Drayton Wiser thermostat is linked, but with a power cut the link is lost, as the socket adaptor would go dead so would not relay the info, it says they have it covered, but are talking about loss of internet, but it seems they will continue to work as independent units, but will not cause the boiler to fire.

Note:- my boiler is battery backed, so power cut will not stop it working, but the router is not battery backed, so control would need to be manual.

As to the "Smart" functions, this should tell me what the heating is doing, but I am not smart enough to really work out what is going on. This from the kasa TRV head is a little more helpful, but the room has two TRV's and a wall thermostat, the other TRV head is much older so only get no charts, but what good are the charts?

The Nest Gen 3 thermostat also produces data, but the Nest and Wiser don't talk to each other, so all it says is when it was switched on, this in real terms is a complete waste of time, it shows when Nest fired the boiler, boiler likely fired by Wiser at other times, and turning boiler on, does not mean boiler is running, once water up to temperture boiler will switch off. If the boiler was on a plug and socket I could put an energy meter in the supply to see when running, but it is on a FCU, so can't easy measure.

And does it matter? If I am cold, I want it to run. And now it does just that. It took some time to get it working as it is today, I made errors, and had to correct, it is not perfect, never aimed for that, I aimed for near enough. So on the odd day I do feel cold, I simply say hey google turn up living room temperature one degree, and it does, I feel that is near enough.