Room heating when temperature drops to 10 degrees - with 7.5 degree away mode set point

[Nibor]

I have a Wised system with a Room Thermostat and 3 Radiator Stats.

I am away at the moment so it is running on "Away Mode" set to 7.5Degrees.

Looking on the app none of the rooms have got below 8 degrees and looking at the graph none have been heating (just a bit of solar gain in the middle of the day).

But one room drops to about 10 degrees then heats up to about 12 degrees then cools again in a cycle (about 2 hrs heating and about 5 hrs cooling). A second room was also doing this a few days ago but has now stopped!

The app does not show that it has enabled the boiler at all.

Any ideas what could be going on?

I have tried lowering the "Away mode" setpoint to 5 degrees to see if that does anything.

The water heating is set to off in "Away mode".

The boiler does have a frost thermostat. So that was my only thought - but would think if that was firing up the boiler the radiator valve would be off so not warmed the room.

[StewartT]

It is annoying that you cannot tell accurately if a trv is calling for heat or not. I would have thought that is a bug of some priority. It is possible that the system is learning the cooling characteristics of the rooms and "experimenting" with bursts of "boiler on" commands. Without more info on the algorithms or access to a fully featured API this is all guess work. Does anyone know how many valve positions the trv's can create and do they drive fully closed when the boiler is commanded "off" - I don't think so.

To put this into perspective I think Schneider have a very good product at a good price and it has to be good that Hub r and the app are on some sort of systems development roadmap, rather than retired so we have to buy Hubr+.

[PhilHornby]

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@Nibor wrote:But one room drops to about 10 degrees then heats up to about 12 degrees then cools again in a cycle (about 2 hrs heating and about 5 hrs cooling).

Is that 10° ~ 12°C measured by the Wiser app - or some other temperature logger?  If the latter, it could just be a discrepancy between how (or where) the readings are being taken. (If for example, the iTRV is close to a cold, north facing wall, it might see 7.5°C, when elsewhere the room isn't that cold).

[mo_mo]

I find at unpredictable times that radiators that should be off are fully on. No indication in the app that there is or should be a demand for heat. My only surmise so far is that the one room that might demand heat according to schedule or override has reached its target temperature and the system has a design that allows the boiler to dump excess heat by choosing some trvs to open up (without this logging in insights).

But while this is plausible, it seems unlikely, given that there is an 'always open' bathroom radiator (towel rail) and that this can happen with two different radiators heating up (in two different cold rooms) for extended periods. I mean, the rads are each fully hot, not just the flow corners, and the room temperatures are noticeably raised.

It seems more likely there's a recurrent glitch in operation.

[Nibor · Accepted solution]

Issue seems to have fixed itself! Which is good.

What would be really useful if the app could include historic graph of when:

1) Heating/Hot water was calling for heat from boiler.

2) Each radiator/room stat was calling for heat.

1 is shown to an extent already in the number of hours per day the heating is on - but be nice to see when on/off over time.