HA can access and display individual iTRV temperatures as they measure it. The room temperature as the Room Stat measures it and heat demand for a individual rooms.
But the results can lead you right up the garden path, if your issue is with a sticking valve. You describe exactly that, as it seems to work ok sometimes and not at others.
Take the TRV control head off and you will see a small pin sticking up. Use a hammer, or something with a flat surface that you can use to press down on the pin and push it into the valve a few times.
Does the travel feel smooth? Is the pin returning to the same up position each time?
If not, it needs replacing. You could try putting a few drops of oil on the side of the pin and see if that improves the movement as a temporary fix. Else hit it with the hammer a few times… it probably won’t help, but might make you feel better
Question about ‘follow schedule’ in the Wiser app… Is that toggle accessible through HA in any way?
Reason being, my iTRV temperature readings in our gym are horribly inaccurate and jump all over the place and extra room stats are silly expensive, so I thought I’d try a workaround. I created a HA automation that reads the temperature from a little Sonoff sensor and overrides the iTRV to ‘heat’ mode when necessary and back to ‘auto’ when done.
It wasn’t heating at all this morning when the CH schedule came on. In the Wiser app, the ‘follow schedule’ toggle for that room was off, unlike the other rooms. Would that be caused by forcing the mode to ‘heat’?
Is there a way to access the ‘follow schedule’ attribute from HA, so that I can make sure it’s set correctly after any manual overrides?
First, I’d check whether it heats reliably without the valve fitted. If not, you’ve a plumbing problem. John’s given the usual diagnostic process for that in his post. Hammer optional
Assuming the plumbing checks out okay, next step would be to make sure the TRV is fitted tight, not able to rotate at all, and recalibrate it.
Last resort, have a look at the history graph for that TRV’s temperature reading. They can be horribly inaccurate and are significantly affected by the position of the TRV relative to the radiator, nearby walls/furniture that might trap heat, draughts, etc. If it’s very different from the real temperature of the room and your other TRVs, I would add a room stat (best solution in a room with multiple rads anyway) - unfortunately, Wiser still has no “temperature offset” capability to correct this sort of thing.
I can understand why Wiser isn’t keen on providing a temperature offset facility for the iTRV. Looking at a typical log of temperatures (attached graph), it isn’t really a constant value.
The blue & yellow traces show two radiator iTRV measurements in one room.
Pink & cyan show the Wiser Roomstat measured temperature and a Sonoff sensor located next to it. They are virtually superimposed on each other.
The violet trace is the Wiser target temperature.
I also did a test with an iTRV physically located next to a Roomstat. (Not fitted to a radiator). Its temperature measurement was identical to the the Roomstat. So they are accurate, but can’t provide a sensible reading when attached to a radiator. Not entirely surprising, when it’s likely changing temperature from say 14 to 60 degrees C.
It maybe is surprising, Wiser even attempt to control a room temperature, by using a radiator iTRV, alone?
If you have a gen2 hub you can buy wiser temperature sensors for a quarter of the price of a wiser room thermostat. The sensor then controls the itrv and hence the room temperature.
Ciaran1 I have tried this here too. In my case, the settings to the Wiser system are immediate - i.e. the system registers the new temperature setting and the climate card reflects the changes accurately. However, depending where the boiler is in its heating cycle, there can a delay before it kicks in again - gas boiler cycles are limited to 6 per hour and oil boilers to 3 per hour. If the boiler has just switched off prior to the new setting, one can wait quite few minutes for the next activation. However, TRVs are activated immediately and the water should still be hot and will circulate.
Thank you @pdm. This makes sense with the delay I am experiencing, in my tests the oil boiler was definitely cycled more times than 3 per hour while show casing and testing the system with my parents. Thank you for your reply and explanation, much appreciated.
Apologies @Ciaran1 - a bit of an error in my reply - the way most system boiler control is set up is for the system controller to activate a circuit valve which in turn switches on the boiler when it is fully open. The boiler, in its turn, controls the water pump, activating it before and deactivating it after a burn cycle. This is limited to 3 or 6 cycles per hour depending on the boiler type. Only a more modern complex modulation system such as EMS or OpenTherm will prevent the on/off cycling.
I changed it to 96 days, as shown here, to give three months worth.
But having said that, if I select over 12 months in the history function, it actually does display at least 12 months…?
I’ve no idea why.
I have LTS (Long Term Statistics) entities for each Wiser device - I recall having to enable these over a year ago, but I can’t find the interface where this is done.
I also note that HA takes a while to draw the entire history chart when you select a long time period - initially only more recent data is shown, then the older data is drawn in. How long did you wait for the chart to finish rendering?
Hi Mark, my post a few years ago stated I could change the OpenTherm parameter to adjust the lower flow rate set point which I had setup and working great, changed it from the default 35 to 45.
I have recently purchased a Gen 2 Hub so I can use the cheaper temp and humidity thermostats but have noticed that I am now unable to set that same OpenTherm parameter now. Same boiler and setup, just literally changed the hub.
Do you know if this is a Wiser thing or could it be something to do with the integration?
My boiler is trying to be super efficient and running at very low flow temps but my radiators don’t output enough heat at 35, hence why I had it upped a little previously.
Thanks in advance
If your question was for me, then that 12 month wiser trace takes around 7 seconds to ‘think about it’ and about 1s to draw it.
I also have an ESP32, using MCP9600’s measuring 3 temperatures, each on a 10 second update time. Selecting a 12 month period for one of those takes around 15 seconds to ‘think about it’, then <1s to draw. They don’t have ‘LTS’ as part of their name, but I don’t know if that is significant.
Downloading data from these show the samples are recorded every 3 minutes, within the 3 months period. Data anything older than 3 months is recorded one every hour. So 24 samples a day.
A total of around 43000 samples for one temperature, for the 12 months…
It was more for @DavidHT as I noticed his chart didn’t mention LTS and I have noticed that sometimes the chart takes longer to draw than one might expect.
I can see room temperature history and heating demand history over the last 110 days separately on their respective graphs but when combined with the target temperature I only have 10 days of history.
Again, It’s likely something to do with the Long Term Statistics option.
Try googling - enable wiser LTS - or similar. The answers vary somewhat on your installation method/configuration. I can’t remember what I did, it was over 3 years ago.
I’ve just tried the history for my ‘lounge target’ and ‘actual’ and the results are similar to the info I posted before. I get up to 3 months of detailed history. Anything older is on an hourly sample.
