Evohome firmware 02.00.19.31 Beta Trial - Exclusive for Automated Home Members

Clive, in your X plan setup do you also have the Intergas cylinder sensor connected?

I set my boiler DHW temperature to the same DHW temperature as EvoHome. When DHW is scheduled and the cylinder temperature is less than 5C below the set point, the Intergas boiler switches to mode 6 and reheats the cylinder at a higher temperature and power setting. This works around the CS92 slow response, as the boiler will stop heating based on the cylinder sensor. I don’t see any overshoots.

There is a BDR91 that short circuits the cylinder sensor when DHW is scheduled off.

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Originally Posted by DBMandrake

Indeed - a global +/- offset to the schedule of all rooms is something I've wanted for a long time, as I sometimes end up implementing this manually. (zone by zone) Sometimes conditions (or occupant preferences!) are such that you just want to bump the entire house up or down slightly while still following the schedule.

I'm just hoping it adjusts in increments of 0.5C and not 1C...

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Re your first comment - totally agree - I end up having to adjust rooms for just 0.5 to 1 c adjustment as the weather warms/cools

Re your second - is there a software programmer who has just broken out into a sweat yelling “but I only thought 1 degree increments would be fine “ 🤣🤣

Hi Kevin, no I don’t have the intergas sensor connected. I did consider exactly what you have done but wanted to try to keep just one setpoint. The CS92 doesn’t seem to be a problem and I’m using it’s measurements it is just that the controller doesn’t output a signal to switch the BDR91 quickly enough for the short heat cycle. I would though if I had to sell the property to a non-techie install exactly as you have. I’m hoping the update will improve the responsiveness.

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Originally Posted by kevinsmart

So no fix to read the outside temperature from an OpenTherm boiler?

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Sorry Kevin, I understand how frustrating it must be to have a local temperature sensor you can't use directly with Evo, unfortunately we didn't have enough time to look into this.

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Originally Posted by CT1

I purchased EvoHome solely for it’s ability to provide fully independent control of. each room, and find most of the more techie features to be a disadvantage, so I am not in a position to comment on the other “enhancements”. I know that many of the members of this forum love to pile on more features, but I am not sure that the general public wants more complications. The plumbers that have serviced my boiler have any all said that they don’t know much about EvoHome and how to operate it.

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I agree with your comments. Balancing feature sets and usability is a tricky proposition and we have tried our best to keep the product as simple to use as possible. I'm hoping that over time we can better integrate and improve usability.

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Originally Posted by clivesanders

Great to see this thread come alive again and welcome to ally153. I run a twelve zone CH plus DHW system and am generally very happy with it. I would normally have participated in the beta test but had only recently had my boiler and cylinder replaced. The boiler is Intergas and the cylinder is a ultra high recovery configured in the so called plan X format with opentherm alone controlling the boiler and one BDR91 for the valve transition between CH and DHW. It all seemed to work well after installation... I have though always monitored the system using an HG180 and Influx/Grafana and as I also brought this back on line I began to notice overshoots in the DHW temperature control. It became obvious that the response of the system to the DHW was too slow. I checked all the usual things and my conclusion is that the Evohome system is not updating the BDR91 quickly enough to work well with the 5 - 8 minutes my cylinder takes to reheat. I solved the problem by taking the BDR91 out of the loop and using the temperature captured by the CS92 / HG180 to operate my own relay on an MQTT system to switch the valve changeover. The opentherm signal operates the boiler as before with the DHW demand. So, in short, I will be interested to see if the new DHW priority can cope with high recovery cylinders. The system as I have with my ‘bodge’ runs flawlessly. I wonder if anyone else has issues with The controller speed of response to switch the BDR91? Just as a side I have confirmed by monitoring the output of Evohome that it is just that the controller that is not responding quickly enough and not RF issues between controller and BDR.

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Hi Clive, what is your cycle rate set to? The default value would be 6 CPH, if you up that value to 12 CPH the BDRs should cycle more often, which might go some way to helping your system.

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Originally Posted by SteveP

Re your first comment - totally agree - I end up having to adjust rooms for just 0.5 to 1 c adjustment as the weather warms/cools

Re your second - is there a software programmer who has just broken out into a sweat yelling “but I only thought 1 degree increments would be fine “ 🤣🤣

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Don't worry, I get to blame AtM if we get the requirements wrong. Luckily in this instance we did make the adjustments 0.5 increments!

Thanks ally153, I had not considered that. It explains exactly what has been happening as sometimes my loop instigates and completes a DHW heating cycle without the BDR ever being called on or off! I have set the cycle time to 12 per hour as you suggest and switched the DHW to BDR91 control. Fortunately I installed a switch so it’s easy to go back to conventional control. It will be easy to see what happens as I am logging all Evohome and relevant opentherm parameters.

Sincerely appreciate your response and will report back after it’s run for 24hrs.

Thanks for the reply Ally. I know I probably come across as rather down on EvoHome, but I believe it is still the only system that meets my needs, even though I only use a minority sub-set of the features. I am therefore very keen to see it continue to suceed and become more widely adopted. My main concern is that it is a bit too geeky for the mainstream and could go the way of Betamax. Also problems like unreliable battery contacts and controller batteries not being charged when the mains fails are very obvious to the user and give the (mainly unjustified) impression of a low quality product.

Looking forward to trying the new firmware when it is released. Keep up the good work.

Wasn't the current BETA meant to be able to read the OT outside temperature? Or are we saying that was intended but never implemented and still isn't? If that is the case what outside temperature is used for the the fancy weather compensation features? Because if its the current Internet displayed one, then unfortunately things aren't going to work as intended. Perhaps a new affordable external temperature sensor is the best way forward.

Also can we please please please get per zone Optimisation back again.

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Originally Posted by ally153

Don't worry, I get to blame AtM if we get the requirements wrong. Luckily in this instance we did make the adjustments 0.5 increments!

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That's great news :)

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Originally Posted by ally153

Hi Clive, what is your cycle rate set to? The default value would be 6 CPH, if you up that value to 12 CPH the BDRs should cycle more often, which might go some way to helping your system.

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Ally153, I set the cycle time to 12/hr as you suggested and whilst it appears to be a little better the loop is still not responsive enough for the fast recovery cylinder.

The call from the Evo controller to the BDR91 seems to be in a running in a time scheduled loop rather than being directly linked to the Cylinder measured value moving above or below the hysteresis window. So, even with a 12/hr cycle rate there could still be a significant delay in the BDR91 operating the valves to switch from CH to DHW and vice versa. Meanwhile the opentherm calls to fire the boiler seem to work in sync with the signal from the CS92. The end result is that the OT signal calls for and fires the boiler up to the DHW setpoint and the heated water is dumped into the CH bypass radiator until the BDR91 catches up and redirects the Flow to the cylinder. I think if you want the system to work in priority HW mode some attention needs to be given to this loop as with a high recovery cylinder the DHW control is not really fit for purpose. I hope this helps and I’m happy to take part in any further beta tests if it is of use. I have used Evohome for many years and am generally delighted with it but would really like to move the DHW loop fully back into it.

Hope this makes sense, I spent a significant part of my career working with sophisticated computerised control of industrial boilers delivering 450kg/sec of superheated steam so I hope I’m not expecting too much of Evohome :-)