Evohome firmware 02.00.19.31 Beta Trial - Exclusive for Automated Home Members

[SteveP]

Yep, I had to give up on "Normal" / "Full" mode as it is too aggressive on my system causing rooms to struggle to meet their set points. Partial works well for me.

yep - same for me - "Partial" being used as "Full" was too aggressive

[Fmb]

Fmb, I was suggesting contacting the Resideo tech support rather than Remeha (no harm in that of course) but Remeha probably won't have much idea what the new Evo features are
Regards AtM

Just got some reaction from the Dutch Honeywell Evohome support.

I asked 2 questions to Honeywell;

1. Could you advice on if on/off controls is a suitable way to control my Remeha Elga Ace 6 kW.
2. A new on/off module is announced for heatpumps; the BDR91T. When is is available? And the be sure, as far as I understand this concerns the BDR91T1004 and not the BDR91A1000. See also https://ensupport.getconn...the-BDR91T?language=en_US

Answer from Honeywell:

Yes, the BDR91 will work, but with a minimum amount of 3 switch-on “actions” per hour. The BDR91T has a minimum amount of 1 switch-on “action” per hour.
Unfortunately we have no information on the availability of products. Everything is sold by wholesale.

So, not a very helpful reaction for now. But at least it tells a difference between the BDR91 and the BDR91T; the amount of lowest switch-on actions per hour. Now I still need to keep searching for one...

[bruce_miranda]

@AtM is there a way to pair a BDR91T as a Zone Valve but to take advantage of the Heat Pump type switching frequency. That would be awesome for UFH zones. Currently my UFH zone switches on and off too frequently due to the inheritance nature of the BDR91 to perform TPI.

[Woody]

Yep, I had to give up on "Normal" / "Full" mode as it is too aggressive on my system causing rooms to struggle to meet their set points. Partial works well for me.

It is a bit counter-intuitive though. According to the Evohome manual 'partial is for very well insulated homes where outside temperature has a minimal effect on heat losses'. One would expect then that choosing 'partial' would heat you home less than the 'full' setting, taking into account that a lower heat loss needs less extra heat. The opposite seems to be true; my certainly not 'well insulated' ground level rooms refuse to heat up to the setpoint when set to 'partial'. They stubbornly stay -1C to -0.5C below the set temperature, which feels cold. The much better insulated top floor rooms don't exhibit this problem. I'll give the fuzzy learning part of Evohome a couple of more weeks. (BTW it does seem that 'cold weather boost' (set @ 0.5C) seems to mitigate this a bit for the ground level floors)

[DBMandrake]

It is a bit counter-intuitive though. According to the Evohome manual 'partial is for very well insulated homes where outside temperature has a minimal effect on heat losses'. One would expect then that choosing 'partial' would heat you home less than the 'full' setting, taking into account that a lower heat loss needs less extra heat. The opposite seems to be true; my certainly not 'well insulated' ground level rooms refuse to heat up to the setpoint when set to 'partial'. They stubbornly stay -1C to -0.5C below the set temperature, which feels cold. The much better insulated top floor rooms don't exhibit this problem. I'll give the fuzzy learning part of Evohome a couple of more weeks. (BTW it does seem that 'cold weather boost' (set @ 0.5C) seems to mitigate this a bit for the ground level floors)

The description in the manual is a bit misleading relative to how it works in practice I agree. What I can gather from observing my system and also some conversation with the Honeywell guys in this thread is:

Partial mode scales the load of each zone down based on the learnt characteristics of the zone but doesn't take outside temperature into account. The scaling factor for each zone is independent from other zones so you may notice some zones scale heavily down and some barely at all. The heuristics used to adjust the scaling factors of the zones over time is not known. (by us)

Normal mode takes the outside temperature into account and further scales the load of all zones down based on outside temperature. If the outside temperature is warm the additional scaling is large if the outside temperature is cold the additional scaling is smaller, but from what I can see in my testing regardless of outside temperature normal mode always scales down the heat demand more than partial mode. So partial mode heats more than normal mode overall.

So if you have any zones that need to call for a high heat demand to reach their set point in winter (as I do) then normal scaling mode always scales down the heat demands too much and never seems to adapt. For those with more effective radiators than mine with more margin it might work OK.

[simonh29]

I'm using the latest update. I've got a mixed radiator and UFH system. For the underfloor I have the HCC80R and also I have T87RF2033 as the room thermostat. I use the OpenTherm bridge.

Everything is connected and working.

However, when only the UFH zone is on (everything else is off in the day and no demand via the system information) and the temperature is in the room is within 0.5C of the set-point the boiler is throttled down by evohome and opentherm to 50% ish. Just like it would with a radiator system when in steady state. But, it closes the actuators and switches off the UFH pump while the boiler is still running throttled down (meaning it is just circulating around my system via the bypass radiator). This sees strange behaviour as to why would you keep the boiler running if all the actuators have been closed and the UFH pump switched off. I understand that unlike the radiator valves the UFH actuator aren't able to be part opened, or the UFH mix temperature changed by the system... but it seems wasteful that it keep the boiler running if it has closed all the valves and recirculation pump... surely it needs to either switch the boiler off or keep the valves open and pump going...

[bruce_miranda]

Have you confirmed that all the Heat Demand is 0 for every zone? Because if it is 0 then OT should not fire the boiler. That's the theory. However what I have noticed is that with OT combined with the boiler pump over run is that often the boiler never shuts down during a heating cycle. Something in the OT chain must be triggering a brief heating demand and that restarts the boiler's pump over run.

[simonh29]

Have you confirmed that all the Heat Demand is 0 for every zone? Because if it is 0 then OT should not fire the boiler. That's the theory. However what I have noticed is that with OT combined with the boiler pump over run is that often the boiler never shuts down during a heating cycle. Something in the OT chain must be triggering a brief heating demand and that restarts the boiler's pump over run.

Yes, there's no other heating demand from the radiators. All stats are set down at 10C and the controller shows 0% demand.

Interestingly I think there is some sort of proportional time given to the UFH. For example, when it shows 5% demand on the evohome it will fire up the UFH pump and actuators for a few minutes every so often. But, I guess with the boiler it is just setting demand % using opentherm. I did notice earlier today it activated the demand was 5% so it opened the actuators and pump but didn't fire the boiler. I'm mapping things out on Domoticz to see how things go.

[oxygen]

I've filled up the form, hopefully, it is still possible to join the beta phase.
I suppose I have a setup that might get usefull (mix of HR91/HR92, a few zones with multiple valves, and a few with a separate thermostat, and separate DHW managed by the boiler directly, OT Gateway & LMU64 w/ OT for the boiler control). Nothing too fancy though. All readings are traced by Domoticz, with both API & HGI80.

I would probably be able to confirm to bruce the HGI80 reading status on Domiticz with the new firmware. We'll see.

[kevinsmart]

Yes, there's no other heating demand from the radiators. All stats are set down at 10C and the controller shows 0% demand.

Interestingly I think there is some sort of proportional time given to the UFH. For example, when it shows 5% demand on the evohome it will fire up the UFH pump and actuators for a few minutes every so often. But, I guess with the boiler it is just setting demand % using opentherm. I did notice earlier today it activated the demand was 5% so it opened the actuators and pump but didn't fire the boiler. I'm mapping things out on Domoticz to see how things go.

I hope to have my multi-HCC80R UFH setup installed next week. As I understand it the HCC80 will employ TPI, so there will be times when an OpenTherm boiler is running with a lower flow temperature but the HCC80 actuators may all be closed. Then after some time, depending on the demand in that zone, an actuator opens. Is that the behaviour you are observing?