Hello forum,
I set out not wanting this to be another one of those “tell me what I need to buy” posts without any additional background where the first reply is invariably “do a search for TRVs in the device forum”; so I have provided a back story. However you will be perhaps commiting 5 to 10 minutes of your valuable time if you continue to read this post, so for that I both apologise and thank you 
.
I’ve had Hive multi-zone (DHW+2xHeating Zones) for a couple of years and as a toe in the water it has been great. It does have some shortfalls (some of which, like the inbuilt overzealous Boost, are taken care of by the great custom Hive climate component), but other than a handfull of cloud outages and a sprinkling of hive hub external temperature wierdness (safe to say I don’t remember a summer where it was 45 celcius in the North East of England 
), it’s been pretty solid. It does what it says on the tin.
However, and it is a big however, I have just returned 16 x so-called smart TRVs and their three associated WiFi/RF/Internet Gateways as IMHO they are simply not fit for purpose.
For those that want to know, they are a re-badged Saswell TRV and Gateway, sold in the UK under a different brand name. Possibly many. I purchased them at the beginning of October last year thinking I was going to do great things with them, but they turned out to be as much use as a raffia paper kettle, so I spoke with the CS department of the well know internet purveyor of things from which they came, and even though the return window closed at the beginning of December, they have approved the return for a full refund. From my perspective a very lucky escape!
The shortfalls of the TRVs and their gateways I have returned were:
-
Scheduling a temperature change - say from 21C to 16C at Midnight (00:00) would not work. The “workaround” was to change it to either 23:50 or 00:10. A firmware update would have resolved this I’m sure, but AFAIK, there is no OTA update facility neither for the TRVs nor their associated gateways.
-
No ability to schedule temperatures via any of the (many different) apps you can use to control the valves (just look at the available apps from the “Saswell” developer in the Apple App store and pick one - they all work with the same credentials as they all talk back to the same cloud provider api.scinan.com; verified with a wireshark trace). Instead, you have to laboriously set the schedules on the valves themselves. This is push-only to the cloud, so if you turn a valve to OFF in the app, or switch a valve to AWAY and then return it to ON or HOME at a later stage, the cloud has no idea what the temperature “was” and therefore sets it to a blistering 16C in the depths of winter. Toasty! Eventually, when the next scheduled temp change kicks in the valve, it will revert to the correct higher temperature, but what a ridiculous shortfall and oversight this is IMHO.
-
Random valve excercising, at least once per day, on the hour, sometimes in the early hours of the morning - which in the first week, resulted in my better half jumping out of bed, opening the window at 6am on a Sunday morning and shouting words to the effect of “stop that chuffing drilling at this ungodly hour!” before I had even realised what had happened - she’s a light sleeper!
-
Probably the worst failing is the random (both in terms of the time of occurence and in terms of which TRV or TRVs are affected) firmware hanging, which manifests itself as a TRV whose display shows the correct setpoint temperature (e.g. 21C, Auto), but fails to open - resulting in a cold radiator and a cold room. The “workaround” for this has been to switch the valve to off in the app, wait 60s, turn the valve to on (35C) in the app, wait 60s, turn the valve to 21C. I’ve even stuck a Sonoff TH16 inside the boiler casing which allows me to remotely switch the boiler permanent live and effectively perform a hard reset; because if enough valves are closed and there is a demand for heat from the Hive thermostat, the flow temp climbs too rapidly and the boiler enters a lockout - no sh!t Sherlock! Imagine… returning home from a few days away to 210L of tepid water in the middle of winter and two ladies who require copious baths/showers… the water was blue as was the air! It’s not a weak signal BTW as I’ve tried one valve on it’s own on a single gateway, right next to the WAP that provides the 2.4GHz WiFi. Same difference.
This last failing was the straw that broke the camel’s back - automation should be exactly that! I should not have to keep checking the bloody app all the time to make sure that a valve has not failed to open when there is a blatant demand for heat.
It does highlight a small shortcoming of the Hive on the DHW side, which is that there is no feedback from the water temperature in the DHW tank…I could fix this with another Sonoff and temp probe, but I suspect I’d need two probes and two Sonoffs to comply with regs - IIRC cylinder stats have to have dual probes on the grounds that if one fails, the other hopefully doesn’t; preventing an overheat scenario; but I’m no expert.
Sooooooooooo, I have a few choices as I see it at the moment:
-
Buy new TRVs - I’ve been looking at the Energenie ones as they operate independently of the Hive and therefore the hubs are not mutually exclusive. They seem to get mixed reviews, but I suspect due to the complexity of installation, some of that may be down to end user error. I would be interested on views on build quality - they look plasticy. A bit of searching and I can get them for around £34 each with a hub coming in at £45
-
Buy a system like the Tado Smart Radiator Starter Kit v3+ which would allow me to add on TRVs via the included hub. This is more expensive relatively speaking. The starter kit retails for £120 and the valves are £70 and I need 16 of them. Ouch!
-
Throw out the Hive and go for something like the Drayton Wiser or Honeywell evohome end-to-end. This is the most expensive considering I already have three zone hive control. I daren’t do the maths - I suspect I’m well into four digits here!
The one complication I see with 3 is that both of these systems (I think) utilise a three zone hub at the location of the old programmer. In my case, the backplate next to the boiler is only wired for DHW and zone 1 heating. Zone 2 heating is provided for with an additional Hive control box, in the airing cupboard upstairs. I have an outstanding (as of an hour ago ) support request with Drayton on this matter, specifically asking if I can combine a 2 zone and a 1 zone into the same system to avoid the wiring from upstairs to downstairs. I’ve asked an additional question in the event that it’s possible, which is what it would look like in the app. To this end, I’m almost talking myself back into energenie TRVs.
Essentially, I want a system that allows me to:
-
control DHW on/off against a schedule. A nice to have would be feedback on current DHW temperature in the cylinder, but this is not essential.
-
control both CH zones independently. A possibility would be to ditch wall stats being the entitys that call for heat and instead use each TRV (possibly in a defined logical zone) to call for heat. Although with our monster condensing system boiler, the ability to get heat away from the boiler via the flow probably makes this a sticking point as the boiler would have the potential to enter lock-out due to insufficient flow.
-
the TRVs need to have the ability to dictate the valve excercise time - I don’t want my wife shouting out the window any more!
-
I would prefer to be able to push the temp schedule to the valves a-la-energenie method, rather than have to set everything up manually on the valves individually. An ability to copy between valves (for example: setup 1st valve in a room then copy the schedule to the other three radiators in the same room - perhaps via an app or web interface) would be good.
-
dual control (as and when I want it) of everything (including TRVs) from within HA where humanly possible. I don’t care (within financial reason) if I have to buy another hub. I already have ZigBee and Z-Wave control within Hassbian, so that doesn’t bother me unduly. The cloud vs. local argument doesn’t phase me either way. I’m more concerned with reliability at this point I think.
I am happy to settle for what I have now with some additional TRV functionality to be honest as, other than a few minor niggles, it has just worked - other than the TRVs of course.
When I did have the TRVs functioning, I had their setpoints at least a degree higher than the repsective Hive thermostat setpoint to prevent the boiler lockout situation. When it worked it worked well, but automation should for the most part be set-and-forget and that it most definitely was not with the addition of these useless TRVs!
Had I been able to integrate the TRVs into HA in some form (via api, ZigBee or z-wave), I would probably have been able to take complete control of them and prevent most of the bad stuff from happening.
Any opinions as to what I should do with/to my system at this point to bring smart TRVs back into play?
Cheers,
bikefright.
. Never mind.
.
- I did not factory reset it, so it had a whole bunch of nodes it still knew about hanging about in the config. As I run Hassbian, there was no pre-built ozwcp, so after my twitching got the better of me, I did the necessary: built it, removed all four TRVs that were working perfectly using z-wave config within HA, cleared out the config (including references in .storage), rebooted, stopped HA, fired up ozwcp and hard reset the bloody thing! Oh joy of joys…I now have nodes 1 through 5! The twitch has vanished.
.
.
I was thinking on buying a Sonoff TH16 with 2 temp sensors to keep an eye on it. Do you currently monitor your hot water tank? If not how are you maintaining the water temp in the tank, is it just using the thermostat attached to the tank?
, so it will be on the back burner until early in the new year.
. This is useful (like in your example) where someone has taken a long shower late at night, when the Hive schedule for DHW is off, thereby reducing the water temp significantly over night…only for someone to get up early in the morning and have a tepid shower because the hive DHW has not kicked in yet!