Smart heating - where to start and how to convert gradually?

ChasingtheWelshdream

In a nutshell,  I’m musing about making our heating system ‘smart’, but want to do this over a gradual time period.

Detail:

Our house is fairly large (3 storeys), and an ongoing renovation project. We are insulating where possible but it is unlikely to be suitable for heat pumps etc, so will be gas heated for the foreseeable.

Currently a combi boiler and 12 rads with manual TRVs. One wireless thermostat. All works fine albeit a little old. Radiators are gradually getting moved/upgraded, as will the boiler someday.

We don’t ever set the heating on time, as our schedules are quite erratic. Working from home  sometimes, out randomly, sometimes wood burner on, sometimes all kids in one bedroom for hours, sometimes all separate rooms. You get the picture. 

We simply put the thermostat up/down to turn on/off when we go out and randomly turn TRVs down if we aren’t in a room for a while (kids at school, us working from home that day etc.) It is a bit of a pain, especially over 3 floors.

I would like to make it easier to control with a smart thermostat and smart TRVs.  

We are on a budget, so can this be done room-by-room over time as we sort the rads?

Our Wi-Fi is over two networks (powerline adapter thingy as our walls are too thick to receive a signal in each room without it). How does that work with smart TRVs?

We may change our boiler to a non-combi one day when we add an extra bathroom. Would that affect anything we do now?

Can I simply go and choose a smart thermostat (Hive/Nest/whatever), start with one smart TRV and add others later on (aka each pay day!)

Can the control be via two smart phones/apps in case one of us is unavailable to tweak things?

As always, any and all thoughts are welcome.

FreeBear

The answer is "yes" to most of your questions. Personally, I'd keep away from Hive/Nest or anything else that relies on an external server. Have a look at the Energenie range of stuff - They do a little interface board for the Raspberry Pi, so I believe you can roll your own server and not rely on an external web site.

BUFF

What exactly are your current boiler & thermostat (make/model)?

Do your research (which you obviously have started).

One thing to watch out for is that some of the boiler manufacturers (e.g. Vaillant/Viessmann/Worcester Bosch) have proprietary communications protocols on at least some of their boilers which means that they only achieve their best efficiency using their own controls. Unfortunately, sometimes the manufacturer branded control may lack something that you want (e.g. several manufacturers have RF thermostats that require a connected power cable whereas I much prefer something that is powered by batteries only for true portability).

Similarly, you can become "locked in" to a system (especilly as your investment goes up) because e.g. their wireless TRVs only talks to their thermostat/hub & vice-versa.

Oh, & watch out for how many channels & zones the system can control.
a) if you change from a combi to a system boiler depending upon the controls system that may require a change/upgrade to the hub
b)  as I imagine that ultimately , as you upgrade your heating system, you could end up with a separate zone valve for each floor.

ChasingtheWelshdream

Thank you, good to know we can do it room by room gradually.

I got lost with the words interface and raspberry pi though…. 

Bendy_House

Three storeys? What's on each floor?

Would an option be to zone each floor so that they are completely independent of each other, and then they can have their own individual settings? This would essentially involve installing a 2-port valve into the 'flow' pipe to each floor. Then each floor would have a Hive/Nest/Tado/Wiser 'stat, set to its own requirements, and overridable by App.

So, instead of controlling individual radiators via Smart TRVs - which would require lots - you'd be controlling zones of rads - eg 'bedrooms' - and each room within that zone would have manual TRVs, or perhaps the odd Smart one.

ChasingtheWelshdream

Mmm, lots to think about and research.

Top floor: Bedrooms, studio and future additional bathroom.

Middle floor: Bedrooms, office, bathroom

Ground floor: 2 receptions, kitchen, laundry/utility, wc.


All rooms are in use each day, some more than others at varying times. Eg the kids might all play together in one bedroom, or they might be antisocial and stay in their own patch. We may be doing different things in reception rooms. But not necessarily. We might put the wood burner for the evening on so not need downstairs heating. But then top floor bedroom may be freezing by bedtime. Kids will get up early and huddle on the sofa with a blanket for an hour or so, so heating the rest of the ground floor seems wasteful until the rest of us are downstairs.

It’s something I would want to do gradually but with minimum disruption each time, which is why I was thinking of the TRVs. But happy to look at other options.

The boiler is a Baxi, approx 8 years old. I will have to check the model. 

Bendy_House

Hah-hah! With that sort of random use, I suspect 'zones' are out! Rooms need to be more individual.

Not sure how many Smart TRVs you can have on a single Hive, but I suspect that will be the way to go (with whatever system you go for). It doesn't mean that every room needs a Smart TRV, of course, but see if you can short-list the ones that would most benefit. Eg, how many bedrooms are being used, are both receptions (at different times), the kitchen? The utility and WC will, I presume, be manually TRV'd to provide 'enough' heat at all times. Eg, utility 'cool', and WC 'adequate'.

With the sitting room requiring full, individual, Smart control, and due to the fact it sometimes has a stove going in there, the main 'stat should be mounted elsewhere, say in the hall. The hall would then not have a TRV fitted to its rad.

Next dilemma is, do you give everyone 'control'...

BUFF

I think that with your sprawling building & erratic schedule there is going to be a certain amount of "suck it & see" & I would probably build it bit by bit rather than going straight to smart everything  - this also fits in with your budget approach.

From what you have said some rooms are likely to heat up more slowly than others & especially if you are trying to maximise efficiency of your boiler by running lower flow temp. when possible. I do think that there will be a role for a certain no. of smart TRV sensor heads as they can be individually scheduled & also call for heat which mechanical TRVs can't (they will also have a "boost" facility). If you buy 1 & find it didn't make an improvement for the room that you put it in you can always move it to another room that you think might benefit - in fact you could probably just buy 1 to start with & move it from room to room to find out which rooms would benefit/benefit most from a smart TRV head.

afaik Tado can handle up to 25 heat sensors/controls & I think Drayton Wiser is 32.
But you can do your own research into no, of zones/sensors etc. for your own situation & then compare systems. Honeywell's EvoHome is probably the most comprehensive system but also one of the dearest ... they do do a cheaper/less featured version in the Lyric range.

Check if your Baxi boiler supports OpenTherm (although iirc Baxi is one of the boiler manufacturers with a slightly less transparent version of Opentherm). They have their own smart control, Usense, but I know nothing about it & I don't know if it has it's own TRVs or can integrate with smart TRVs from other systems.

Grumpy_chap

ChasingtheWelshdream said:

Our Wi-Fi is over two networks (powerline adapter thingy as our walls are too thick to receive a signal in each room without it). How does that work with smart TRVs?

I can't answer the heating control question, but we previously had split WIFI networks using powerline.

We then changed that a while back now to Google Home WIFI, which is a mesh system and creates one wifi network even though it is boosted by the different modules. 
We have this one:
https://store.google.com/gb/product/google_wifi_2nd_gen?hl=en-GB
But we have the first generation and I note the second generation is rather more expensive.  Google also seem to offer a Nest wifi which is also a mesh system.  I don't know why they have two versions of the same thing.

There are alternative mesh wifi systems available so if you like this idea, have a look at the current market and see what would
meet your needs best.

Typhoon2000

Smart TRV don’t normally work on WiFi as it would use too much power and the batteries would run out quickly. They communicate with the hub over a low frequency and the hub is connected to WiFI.
Also you can set the WiFI SSID on the power line adaptors to match you main internet wifi hub and the you the same network name through the house.

ChasingtheWelshdream

Thank you all, lots to read up on!