As far as I can see the code doesn't need to know whether there was a manual override set before before Eco mode was enabled (and therefore be trying to restore anything later) because cancelling Eco mode already cancels all manual set point overrides and goes back to the scheduled temperature (follow schedule mode) anyway - just like every other quick action change. So there's nothing special for it to do.Quote:
Originally Posted by ally153
So any manual override made during Eco/Boost can just be set as is to the desired temperature, then when Eco/Boost mode is cancelled or timed out, the set point override is cancelled anyway. And if the set point override expires first before Eco/Boost is cancelled it just reverts to follow schedule with Eco/Boost override applied to the scheduled temperature - as it does now.
The way it tries to add the Eco/Boost offset on top of manual overrides is quite a significant problem IMHO, there's going to be a few very puzzled people when they try to apply manual overrides with Eco/Boost set and find that it is "fighting" them. It makes getting the desired manual override a bit of a chore even when you do understand what's going on.
Perfect - that's pretty much exactly how I hoped it would work so excellent job there. :)Quote:
If the difference between setpoint and ambient is 1.5C or more we now completely ignore scaling. Between 1.5C & 0.5C we start backing off the demand to the point we're fully scaling again by 0.5C. Where I think load scaling works well is when running in the background with your schedule gradually and efficiently controlling room temperature - it's a bit like the difference of gradually increasing speed on a motorway v.s. being heavy footed on the accelerator.
Agreed. I saw similar improvements in my graphs this spring with 19.31. Load scaling is great for warmer weather with light demands (I no longer have to manually turn down my flow temperature in summer) and also schedules where the house may be in equilibrium for a few hours and then a zone like a bedroom is scheduled to come on - with no load scaling that bedroom would bring the boiler demand instantly to 100% and remain there for perhaps half an hour until the zone started to approach the set point, this would inevitably cause uncomfortable overshoots in other rooms like the Living room that were previously in a nice equilibrium state as those rooms were not expecting a sudden step change in flow temperature. I noticed this a lot last winter.Quote:
Below is an example from my home showing load scaling being applied to a scheduled setpoint change, then later me manually overriding the setpoint. You can see the difference in behaviour in the zone's demand and also see how the temperature settles around setpoint with scaling on vs the overshoot with the heavy-footed override behaviour.
Attachment 1587
Load scaling V1 (in 19.31) solved this problem nicely and pretty much did away with schedule related overshoots in most of my rooms this spring, (some rooms like the bathroom are irredeemable due to towels over the sensor etc) but then introduced the issue that I couldn't get any heat in summer from normally low demand zones like the bathroom unless it could piggyback on the demand from other zones. I could literally turn it up 5C above the current temperature and wait for an hour and nothing would happen because the 100% demand was being scaled down to something like 5%. (Even on partial mode!)
I think the new behaviour in 19.33 is a good compromise and will allow me to leave load scaling enabled, also I would recommend others give load scaling a try.
Ok that sounds good. My test was quite simple - attach an HR92 to a spare valve body and put it in the freezer long enough to get the sensor below 5C and monitor the heat demand generated. This previously failed with load scaling enabled, (the load was scaled down to below 11% thus didn't meet the minimum on-time required to fire the boiler) but worked with load scaling off. If I get a chance I'll repeat the same test with load scaling left on.Quote:
Temperatures under 5C are treated as a frost protection fail safe condition. We decided that it made sense to simplify the control logic and rely purely on our traditional adaptive fuzzy in these conditions. We felt that this would also avoid confusion or doubt that Evo could handle these situations correctly. When the room ambient increases above 5C, load scaling will kick in again, but as previously mentioned, there are built-in failsafes, should the system struggle with load scaling enabled.
As frost protection is effectively a setpoint of 5C, while maintaining 5C, load scaling might apply (if the room temperature is slightly above 5C) but won’t apply when getting up to 5C.
It's great to see some feedback being taken on board - 19.33 feels really solid to me (manual override in eco/boost mode aside) and many of the new features since the last stable release are genuinely useful, like load scaling, the option to enable/disable hot water priority etc.Quote:
I’m interested in how people will use the new weather features and what deficiencies they see in it. The feedback will help shape how these features work in the future.
After a long time with fairly minimal updates (I've had my system for 5 years) it does feel like the software is moving forward a bit.
