Another Thermostat / TRV question

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MrDibble

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So I think it's time to zone our heating for a variety of reasons:

I work from home and my wife is retired. So one or both of us are home most days. If the heating's on we don't really need the bedrooms heated all day.
Our living room has a large South facing patio window meaning it gets a lot of solar gain. So on cold but sunny days the living room is warm enough but the rest of the house suffers as the living room thermostat doesn't call for heat.
My office doesn't need heat in the evenings.

I think I'd like to use electronic TRVs - I did install zone valves in our last house but they were quite noisy and we could hear the "chugga chugga" sound of the actuator travelling through the pipework. I'd like central control but I really do NOT want anything cloud-based!! I do not want to be stuck if a server goes down, or xxx company goes bust or decides to pull their service, or moves to subscription-based services.

I've seen Honeywell's evohome but it seems to be quite dated and I've read some bad reviews. The Drayton Wiser looks OK but not sure if it works offline? Not sure what to make of Tado... Anything else I should consider? Oh, we have an oil boiler so no OpenTherm or modulation.
 
I have Wiser on our system boiler.
Due to layout, I replaced the hall stat with a single channel one and left the old timer to take care of the hot water tank.
It does work without internet. Uses Zigbee locally I believe. No internet would mean no control away from home.
The smart TRVs are pretty quiet when switching.

I looked into Evo and Tado. Both seemed good. I believe Evo is the best but does look very dated.
Bought Wiser based on price. The kit with 5 TRVs was £280 on Amazon. Now £400.

I had one of these for the Mrs home office before Wiser. Still relied on the hall stat to fire but wasn't heating evenings/weekends
Was £20. Now £40.

Cold weather and fuel prices has probably pushed demand/pricing on smart heating.
Might come down when it gets warmer.
 
I used the eQ-3 which @mcprinter has linked to, cost £15 each in 2019 when I got 5 of them, they work well, but will not turn on the boiler, what matters is how the boiler is activated.

What I have done is set the master wall thermostat to go down 0.5°C an hour before a TRV is going to increase temperature, then back up 0.5°C as the temperature is set to increase, this means boiler fires up when required.

Wiser TRV heads are claimed to have algorithms which work out how long it takes to heat the room, so you set time you want room warm at, and it works out when to switch on, however it would need internet connection to know how warm it is outside.

The Nest Gen 3 wall thermostat I have was claimed to do the same, however it all depends on what doors are open or closed, so in real terms it does not work. It also has a load more useless features, this 1673396543234.png claims to show how much energy used, what it really shows is how long the boiler was switched on for, but the boiler cycles on/off and the mark/space ratio changes depending on how many TRV's are open, so the chart is useless.

Same with geofencing, yes it works, we travel from Mid Wales to North Wales and it detects our phones are not at home, and turns heating to Eco mode, but our house takes some time to warm up, so unless I manually go into the program and turn up heating before we leave North Wales, we return to a cool house, how far ahead it turns the heating up I don't know, it does not give one the ability to set distance only comfort and Eco settings.

Nest has all in all been a failure, it is a complete load of rubbish, but better than what I had before, which entailed leaving the main house, walking down a set of steps to under house, and plugging in pump for boiler. I selected Nest as was told it worked with Energenie MiHome TRV heads and I already had 4 of them, and it only needed two wires between main house and where the boiler is to keep the thermostat charged and send the signals to turn boiler, pumps, and motorised valves on and off. It does not work with Energenie TRV heads, seems support was withdrawn.
 
ericmark said:
Wiser TRV heads are claimed to have algorithms which work out how long it takes to heat the room, so you set time you want room warm at, and it works out when to switch on, however it would need internet connection to know how warm it is outside.
Click to expand...

Internet is required but a temporary outage won't stop the system working.

My understanding is that Wiser learns how the house heats and cools over time.
I think a variable start time is only in comfort mode.
 
It seems no heating control is perfect. Each one has plus and minus faults, I did look at the iVector fan assisted radiator from Myson, but the building management needed to control it costs too much. Also it does not control the return water temperature so to work with a modulating boiler really need it plumbing in series not parallel.

Wiser and Hive single channel is volt free, rest are not, and all too easy to fit wrong model. Hive does not have opentherm. Nest will not work with TRV's. Tado seem to want to keep things a secret, told the opentherm version not available in UK. Evohome and Wiser the OpenTherm is an add on extra, it seems only EPH works with hard wired zone valves and OpenTherm with a master/slave arrangement, the list goes on, there is no one type suits all.

The guides I have found have errors, I know Nest no longer works with Energenie. And the comparison table does not seem to tell you things like how does geofencing work.

The colder the ambulant temperature the longer it will take to reheat a room, so one wants either the differential between comfort and Eco setting to reduce as the temperature drops, or the distance from home when it swaps between the two to increase, I have not found one which does either, it may exist, but I have not found it.

When I was in the last house the 4.5 kW gas fire, and 4 kW standard radiator plus 3.5 kW fan assisted radiator could heat main room from cold in around 15 minutes, there was no real need for any geofencing, it in the main used a simple timed setting, but this house main living room takes around 2 hours to reheat, so at an average of 40 miles per hour, it would need to activate at 80 miles away, which would be very rare. So only way would be to let house become progressively cooler the further from the house I travel, and the reverse as I return, so my weekly trip to railway ¼ mile away to volunteer could not be catered for using geofencing.

And I know I forget if not automated, so arrive home to a home too cold or too hot, odd but tend to remember to switch on AC in the summer, it's the heating I forget about.

But even in the house, if I come to use a room not normally used, all I need to do is press the Eco/Comfort button on the TRV, but until I feel cold, I forget to do it. As to using the mobile phone, when I get home I put it on charge, so using it to turn heating up/down or lights on/off is not really any good.

The hall thermostat has a built in PIR but I don't live in the hall. Likely best plan would be replace the internal LED lights with tungsten so switching on lights would warm the room. But electric costs more than oil. Suppose could have oil fired wall lights, tilley lamps work well, but a pain to light.

So we are stuck with near enough heating systems, although a tilley lamp on the wall would be a talking point!
 
ericmark said:
It seems no heating control is perfect. Each one has plus and minus faults, I did look at the iVector fan assisted radiator from Myson, but the building management needed to control it costs too much. Also it does not control the return water temperature so to work with a modulating boiler really need it plumbing in series not parallel.

Wiser and Hive single channel is volt free, rest are not, and all too easy to fit wrong model. Hive does not have opentherm. Nest will not work with TRV's. Tado seem to want to keep things a secret, told the opentherm version not available in UK. Evohome and Wiser the OpenTherm is an add on extra, it seems only EPH works with hard wired zone valves and OpenTherm with a master/slave arrangement, the list goes on, there is no one type suits all.

The guides I have found have errors, I know Nest no longer works with Energenie. And the comparison table does not seem to tell you things like how does geofencing work.

The colder the ambulant temperature the longer it will take to reheat a room, so one wants either the differential between comfort and Eco setting to reduce as the temperature drops, or the distance from home when it swaps between the two to increase, I have not found one which does either, it may exist, but I have not found it.

When I was in the last house the 4.5 kW gas fire, and 4 kW standard radiator plus 3.5 kW fan assisted radiator could heat main room from cold in around 15 minutes, there was no real need for any geofencing, it in the main used a simple timed setting, but this house main living room takes around 2 hours to reheat, so at an average of 40 miles per hour, it would need to activate at 80 miles away, which would be very rare. So only way would be to let house become progressively cooler the further from the house I travel, and the reverse as I return, so my weekly trip to railway ¼ mile away to volunteer could not be catered for using geofencing.

And I know I forget if not automated, so arrive home to a home too cold or too hot, odd but tend to remember to switch on AC in the summer, it's the heating I forget about.

But even in the house, if I come to use a room not normally used, all I need to do is press the Eco/Comfort button on the TRV, but until I feel cold, I forget to do it. As to using the mobile phone, when I get home I put it on charge, so using it to turn heating up/down or lights on/off is not really any good.

The hall thermostat has a built in PIR but I don't live in the hall. Likely best plan would be replace the internal LED lights with tungsten so switching on lights would warm the room. But electric costs more than oil. Suppose could have oil fired wall lights, tilley lamps work well, but a pain to light.

So we are stuck with near enough heating systems, although a tilley lamp on the wall would be a talking point!
Click to expand...
Opentherm support is standard with Drayton Wiser.
 
All the kits come with a hub which includes the OT module. All kits also include a room thermostat. The multi zone kits include two TRV’s.
 
Some interesting comments for me to think about! Wiser may well be the way for me to go, I'll have a closer look at it.

I don't really trust Google with Nest... mostly because it's cloud based and I don't really want anything like https://www.fastcompany.com/9035839...nest-users-couldnt-unlock-doors-or-use-the-ac , or Elon Musk buys Google and decides to can it or they decide to charge 4.99/month for it, or whatever...

I need a hub which can call for heat, so individual TRVs are not really suitable.

Actually what I'd really like to do is hack some TRVs and make my own, as my background is embedded electronics. But I know deep in my heart that would end up a long term project and I'd be facing the wrath of a cold MrsD somehere down that line :eek:
 
MrDibble said:
I don't really trust Google with Nest
Click to expand...
Neither do I, I got 4 x Energenie MiHome TRV's as claimed to work with Nest, with idea of adding Nest latter, when I go around to adding Nest the TRV and Nest would set to same heat using the MiHome app, but when the Nest thermostat changed temperature on schedule, the TRV's failed to follow, and that is really wrong way around anyway, the wall thermostat should read the TRV, not the TRV read the wall thermostat.

It seems Nest USA has temperature sensors so it will fire up the furnace (they don't call it a boiler) if any room under temperature, but Nest USA is completely different to Nest Europe, and they have not been released for Nest Europe, and at £35 each seems daft having a TRV and a sensor rather than built into the TRV.

That would be like having hard wired zone valves and TRV's when both do the same job, a TRV is a zone valve, OK if a zone is rarely used, like in my case the flat under main house, it makes sense to turn off four rooms together, but unlikely to make sense in a normal house where rooms can change designated use from bedroom to office as children leave home.
 
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