It’s in the raw data provided by the hub. You would need to use the cli interface to view the information until/if it’s added to the integration.
Or use the “Download Diagnostics” from the Wiser HeatHub’s Device info.
Then use Notepad or equiv to open the downloaded file.
This is assuming you are using a browser on a PC.
Question on using Opentherm mode:
- chFlowActiveUpperSetpoint: is this sent to wiser from the boiler? Can it be configured?
- preDefinedRemoteBoilerParameters.maxChSetpointUpperBound: same question, is this sent to wiser from the boiler? Can it be configured at the boiler side?
- RelativeModulationLevel: Can anyone explain this? I expected that modulation level is a number 0 to 100, but in my case it is often 230 or 400 or even 600+. Not sure how to interpret it. Is this something sent from the thermostat to the boiler or from the boiler to the hub?
I don’t know for sure but in my opinion and with my “Ideal 35” boiler:
-
chFlowActiveUpperSetpoint": is 800, Which equates to 80C and is set at the boiler with a control Knob. So I guess this is sent from the boiler to the Wiser Hub.
-
maxChSetpointUpperBound": is 830, I suspect but I have not delved into the boiler menu settings, that this is is configured in the boiler as well and is sent down to the Hub. This comes under the “preDefined” heading as does maxChSetpoint which is 800 in my case. This matches the setting in the boiler.
3 RelativeModulationLevel - I too would like an explanation of this. My modulation level can go from zero to 1000. I graph the attribute along with outflow and return flow temperatures.
I also notice that the maxChSetpointReadWrite flag is false which I assume means the Hub can’t override the max setpoint.
I think the algorithm in the Hub just sends a % demand value to the boiler and the boiler then calculates the flow temperature based on upper setpoint and the lower setpoint.
“chFlowActiveUpperSetpoint”: 800,
“chFlowActiveLowerSetpoint”: 350,
So a 50% demand equates to a flow temperature of 57.5C and the boiler modulates to maintain this.
If anyone knows if this is true or false then I would gladly be corrected.
That’s great analysis, I’ll so do more digging. My assumption was that
a) maxChSetpointUpperBound is something that is the default for the boiler (sent from the boiler)
b) chFlowActiveUpperSetpoint: I think this is something that is supposed to be sent from the thermostat to the boiler (in order to configure the upper flow limit).
But again, not sure about the above.
On max flow: On most boilers when opentherm is used, you can no longer configure the max flow temperature at the boiler side using the knob/buttons - it gets disabled and overriden by opentherm.
However wiser through the app does not give the ability to actually set this (e.g. in case you want modulation to happen from 35 to 60 instead of 35 to 80).
I know that Tado can actually configure the ‘max’ flow temperature using the “professional” version of the tado app or by contacting support, who make the necessary change on the thermostat; its a message sent from the thermostat to the boiler.
I agree on a)
On b)
I am not sure that this is sent from a thermostat more likely from the Hub. But, in my case, this doesn’t change, it is always 800 (80C)
Max flow
I thought this was set by the boiler but I changed the boiler max temp to 70C and you are correct this is overridden by the Hub. So it was just a coincidence in my case they were set the same. I should have tried that before Doh!
I have read in this blog people calling the wiser integration service to change this to do what you wish, but it does not stick and is overridden on the next poll, suggesting this is not configurable.
Tado - does your statement assume there is only one thermostat? Am I misunderstanding this? Wiser heat demand comes from several devices and I assumed the Hub cleverly consolidates that into a demand from the boiler with the water sent to the relevant zone by controlling the iTRV’s if you have them.
I have monitored the demand and flow temperatures and there is a direct correlation between demand and flow temperature. The only deviation is when my combi boiler is used to provide domestic hot water at the same time as heating demand.
Maybe @jamiebennett can help here (without giving away his company’s IPR 
I did some further research and now i believe this:
Everything under preDefinedRemoteBoilerParameters (including maxChSetpointUpperBound):
These are parameters sent from the boiler to the hub, one way. Not adjustable from the hub. So it’s the maximum flow temperature supported by the boiler.
chFlowActiveUpperSetpoint: This is actually what the hub uses for modulation (possibly also sent to the boiler) and the boiler is modulated with this as an upper limit (as you suggest).
Wiser seems to always configure this to 80 for max and 35 for min - this is the same for my system too.
Sorry by thermostat i meant really the ‘thermostat system’ - essentially the wiser or tado hub - nothing to do with individual rooms or room thermostats.
In Tado’s case, the system can be configured with a specific maximum flow temperature that will be respected by the boiler during modulation - so you can configure modulation to be from 30 to 60C if you wish. This is possible either by calling Tado support (they’ll configure your hub accordingly remotely) or the last couple of months after an update it can also be done using the Tado app for installers. So their hub has this capability, and they also exposed it.
It looks like wiser can’t do this at all. It’s an opentherm message that must be sent from the hub to the boiler.
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That’s really interesting.
With regard to your Tado comment. What if you could set the max flow temp to 60C but the zone setpoint cannot be reached? The boiler would be on 100% demand and be burning gas constantly but never being able to achieve the desired temp. Not a good situation.
Much better in my mind, to set a max flow temp that can achieve the desired setpoint. I.e ignoring a set max flow temp. This is what I see the Wiser Hub doing and is quite clever.
Before I configured my boiler to OpenTherm, I had the max flow temp set at 60 ( as the government advises and to max the condensing efficiency) but the boiler failed to raise the temp in certain zones to the setpoint temperature so I had to turn the boiler up. Therefore even if it were possible to set this via OpenTherm and Wiser I wouldn’t because I know it wouldn’t be efficient.
What I do see with OpenTherm is that the boiler is on more frequently but at a lot lower temperature so in effect it is the pump that is running distributing the latent heat in the system and the boiler just firing occasionally to maintain a flow of usually around 40 to 50C if the Hub sees a demand. Of course it is more intelligent than that as the hub doesn’t shut the iTRV’s off in the relevant zones even though the setpoint has been reached and uses the heat in the system to keep the relevant rads ticking over until there is a potential further demand or there is no demand from the schedule in which case the iTRV’s close with no demand from that zone on the system at all.
(I think this is something like the “passive mode” both @robertwigley and @msp1974 have implemented in the integration for traditional systems?)
Below are graphs showing the direct correlation between scheduled demand and flow temperatures.
The flow temp spikes are domestic hot water demands.
Its a basic feature to be able to set the maximum temperature, the problem is that with wiser its not configurable. Yes, a low max temp runs the risk on taking longer to heat a room or never reaching the desired setpoint - that’s an acceptable risk. If that happens, I would set the max higher. To do all that I need this max temp to be configurable!
This is a standard feature supported by OpenTherm and other thermostat systems as well.
All the other things you say has been my experience too - with opentherm the boiler is on for much longer but usually at low temperatures and at low burner flame setting (the boiler modulates the burner based on temperature delta).
With regards to the TRVs: The TRVs themselves modulate how open each radiator valve is independent of the boiler/opentherm modulation. So if a room is 50% demand, the iTRV will be 50% open - and the valve will close down or open up depending on room demand. They only close when demand for the room is 0%.
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Did a bit more research on this. First of all, this number is sent from the boiler to the hub (instead of the other way around).
Second, this refers to the output level of the boiler.
It is a percentage value. So 230 is 23% of the total heat output of the boiler in kW.
So if a boiler is 35kW then 230 modulation level means it is operating at 8kW output.
Note that this takes into account hot water demand as well. So if you open a hot water tap you’ll see the modulation level jump to above 600 and the flame be stronger.
Just had my new boiler commissioned yesterday and I got the engineer to swap out all the 25 year old Danfoss valves for the Drayton auto balancing valves.
The bit I can get my head around right now is the CH pump. Does it stay on constant speed, should it be on constant pressure or variable pressure? None of the advice is clear on that in regards to the auto balancing valves.
Autobalancing valves may lead to the system being actually out of balance more easily under certain conditions. This may happen when (a) you have a variable speed (variable pressure) pump (which is the case for typical combi boilers) and (b) you do microzoning using iTRVs, and your usual pattern is that e.g. more than half the radiators are shut while a few of them work.
For the details you can watch this video and read the comments Automatic balancing TRVs - Are they worth it? - YouTube
In short, it’s because on auto-balancing valves you need to set a specific flow rate on the valve, and the valve will try to maintain it. But due to variable pressure pumps and microzoning, the total system pressure may be less than the total of all flows for all your rads, leading to unbalancing.
So in summary: If you plan to use a variable speed pump in variable speed mode, then it’s probably best to get new not-autobalancing valves. If you have a constant speed pump, or you use your combi pump in constant mode then its probably ok to get autobalancing valves.
Thankfully it’s not a combi, and leaving the pump on constant speed is the way forward
Hmmm.
Good news and bad news.
Once the iTRV passive mode is released, 
I’ll have little reason not to buy more iTRVs 
I’m making do with three at the moment.
Kitchen, lounge (with a roomstat display) and a bedroom.
But meanwhile…
Could anyone explain or give a pointer to information on the Wiser Smart-plug
There is a kWhr totaliser value shown in HA.
Is this value created and stored in the device itself or in HA?
Unplugging/un-powering the device does not change it.
Can it be reset to zero?
If so, how is done?
It’s stored in the plug and I think you have to reset the plug to set back to 0.
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These are good points. I take it you didn’t ask your plumber/heating engineer, or they simply didn’t know?
I think, as @georgek has suggested, keeping the pump on a constant speed setting probably makes sense, but I really don’t know for sure. Maybe @jamiebennett can advise, or ask his colleague James (who does the training videos on YouTube). I’ve been watching a number of these, and I don’t recall having seen it addressed in any of them.
I’d like to hear how you get on with the auto-balancing valves. Whether you notice any difference, problems etc, as I am potentially planning on having them fitted on all my radiators when the warmer weather comes in so they are ready for next winter. I didn’t really fancy having the system drained down for a day in the middle of winter.
Ok. Thanks.
Maybe that’s another suggestion I’ll make for Wiser support to provide in the app.
It would be useful.
@jamiebennett Some feedback on the new firmware (3.12.1). Although it’s early days, I am still seeing intermittent disconnections at roughly the same intervals as before. Time will tell if it’s more or less fequent, or largely unchanged.
However, instead of taking hours to reconnect, it now seems to be re-establishing a connection almost exactly 5 minutes after disconnecting. This is a massive improvement on what we had before.
I assume something in the firmware stack has been set to force a reconnection attempt 5 minutes after registering as disconnected. I’m just wondering if this time interval can be reduced in a future firmware update to improve this further?
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For most people the WiFi disconnections should be resolved but for some users we just don’t know why their particular networks are causing issues for Wiser. Among all the improvements we have introduced more diagnostic information that will hopefully help us to learn more about these troublesome installations. What we will do is monitor this and tweak things as necessary. For now, I hope it is much better for the vast majority.
Thanks for the feedback.
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Some feedback on the latest beta and passive mode.
Other than my initial confusion about not seeing the new dropdown entities after upgrading and having to re-enable passive mode in the integration options and delete the old entities (thanks @tombadog for the tip), I’ve been running without any noticeable issues for about a week now.
I’ve even found the Passive Follow Schedule mode useful for one room, which I wasn’t actually anticipating finding a use for.
The only thing I would suggest, which is really just cosmetic is regarding naming of the passive mode dropdown entries. Instead of “Disabled” I would suggest “Off” and for the other two, drop the Passive (it’s already part of the dropdown name anyway) and have “On (Manual)” and “On (Follow Schedule)”, which I feel is clearer and should fit without being cut off when you have a them in a two column grid. Just my two cents.
