Considering Evohome

[mattih52002]

Hi,

I'm slowly applying smart technology to my house, so far, I've automated some lighting (indoor and out), ventilation systems for bathrooms and underfloor electric heating.

The one thing I would like to have more control over are my heating bills. I live in a fairly large 4 bedroom detached house which is all heated when the boiler is on; I can control rooms by turning the TRV's down but that would be a pain ;-)

Honeywell Evohome seems to be the way to go...

I wondered if those whom have Evohome have any suggestions, learnings and experiences or things they wish they'd have known prior to committing themselves to the system.

Thanks

[g6ejd]

My situation is similar, this is what I've learnt:
1. Installed Honeywell TRV's (as a precursor for Evohome) replacing 16-old variants, noticed an immediate improvement in comfort and control of room temperatures, room that previously were heated no-longer were, rooms that were previously cold were now a nice even temperature.

2. Then I installed the Evohome and so-far I have not noticed any reduction in gas consumption, but I have noticed an even higher comfort level and now our cloakroom which was always cold remains a nice even temperature and it's never been like that. Also being able to control (12-zones) each room individually is a bonus, like only having the bedrooms on at night but not the two spare rooms or dining room, etc. There are no more cold or hot spots.

3. Because I know the gas consumption (recorded every week for the last n-years) I now know that the consumption has not changed, certainly not achieved the range stated by Honeywell (25-40%) but then I think this house is already at the high end of energy efficiency and NPower tells me we are about 18% lower than similar houses in this post-code. I had the Nest before and that is reasonable at energy management, so switches off if you leave the house, predicts coming home and does predictive on/off controls, most of which is done by the Evohome. I think now I've traded improved energy usage for improved comfort like selective rooms heated at night, which I am pleased with.

4. Would I install it again, yes definitely, but with the controllers, HR92's and new TRV's it cost me ~£1400 so this was never for a good return on investment through energy saving but about comfort which is improved markedly.

5. Mrs.B says that the system has become technically unattainable to her, but I need to train her in its operation like turning up a room temperature and being patient while it works. She also thinks its a backwards step because the HR92's make a whirring noise at night (well anytime they make an adjustment) and thinks that's' old technology and a bit clunky, she may be correct but I convince her about the other benefits and she sees the logic and says it's the first time the house has been consistently warm since we moved in.

6. When Npower came to replace a failed 3-port valve they told me they could not do it, because they would need to call in specialists as it was beyond their knowledge, but I managed to convince them I could do all the driving and it was the same system as 'standard', so that's an important consideration if you have a maintenance contract.

[paulockenden]

I agree re comfort vs cost savings. My bills have gone down, but comfort is far more important.

My wife, like yours, is struggling with the system, and wants to go back to simple controls.

[DBMandrake]

Although you'll see me nitpicking subtle software bugs and minor hardware issues (like battery contacts that needed adjusting) on various threads on the forum on the whole I love the system and would never go back to the crude controls we had before.

Like both of you the motivation for me was not trying to achieve a cost savings in gas, but to increase comfort - through better regulation of temperatures, and convenience - in the form of independent control and schedules for each room, smart phone remote control etc.

In fact the first few months of winter we had it I think our gas usage actually went up a bit (we only had half a winter of experience with the old system after moving in so its hard to be sure) because I was being very liberal with scheduling unused rooms through the night like the living room being scheduled to 14 in the middle of the night - when it really wasn't necessary, and also having the bedroom warmer than it needed to be.

This compared with our old system where the timer was simply OFF at night, so no gas use at all through the night. (but also a freezing bedroom) So clearly gas use had increased at night time. As soon as I realised my mistake I scheduled all rooms except bedrooms to 5 degrees (frost protect) over night and dropped the bedroom temperature a few degrees and usage has come right back down again.

Our summer usage is significantly less than what it was with the original controls as the system does a good job of knowing when not to call for heat when the room doesn't need it, thanks to every room being able to independently call for heat based on its own needs rather than one wall stat in the hallway.

I'm very impressed with the temperature regulation in most of our rooms. The first winter we had the system the living room used the built in sensor in the HR92 (radiator valve) and it was a massive improvement over the temperature regulation of the manual TRV it replaced - which was god awful, with the room always either too hot or too cold and never really comfortable. (The human body feels temperature changes more than absolute temperature, so comfort is achieved by a steady temperature that doesn't cycle up and down rather than a specific temperature, as long as you're in a certain range from about 19-22 degrees)

Frequent trips from the sofa to the TRV to make manual adjustments were the order of the day, as well as trips to the hallway stat to turn that up if the boiler had gone off and thus the living room couldn't get any heat from a non-running boiler. The end result was the unused hallway was always roasting just so we could keep the living room up to temperature in the evening, and that wasted heat in the hallway always annoyed me.

We now have an HR92 on the hallway radiator as well and in conjunction with an ABV there is no longer a "bypass" radiator that must always get hot when the boiler is running. So we can schedule the living room to be comfortable in the evening with the door closed with the hallway radiator scheduled to be off or set back a few degrees. In fact we can turn any individual radiator on in the house without a bypass radiator getting hot - useful for heating the bathroom for a shower even in warmer weather when the rest of the house doesn't need heat for example.

After installing an HR92 in the living room I immediately noticed the temperature was a lot more steady and consistent with good comfort. For a fixed set of conditions like consistent weather outdoors the temperature regulation was spot on, however I noticed that large swings in the weather would require a small manual adjustment to the temperature - for example in mild weather I would set it to 20, in cold weather 21 and in really cold sub zero conditions I had to turn up the living room to 22 to achieve the same subjective feel of comfort. Once set for that nights conditions it maintained the temperature and comfort very well however, unlike the manual TRV.

This winter I have a DTS92 remote wall temperature sensor in the living room instead of using the HR92's built in sensor and the level of comfort and control has increased even further - now I don't even need to make any manual adjustments based on outdoor conditions. The room is scheduled for 20 degrees during the day (weekends) and 21 degrees from about 5:30pm, and that is it, regardless of weather.

What has really amazed me is we have gone from very mild weather (12-14 degrees) just a week or two ago to about zero degrees in the last couple of days and we are blissfully unaware of this in the living room - without touching the temperature schedule at all the room feels perfectly comfortable and we are completely unaware of whether its mild or really freezing outside - until we step outside! The temperature regulation is that good with a remote sensor.

As far as convenience goes, independent schedules for every room is great - it does take a long time to figure out what each rooms schedule should be, and from time to time you will need to change it (visiting guests, taking annual leave etc) but once you have it dialled in you can do some clever things.

Because each room is a set point schedule rather than an on/off schedule you can schedule different temperatures for different times of the day. For example our bathroom is scheduled for 22 degrees for shower time on a weekday morning, then half an hour after people leave for work it goes off - giving time for towels and bathroom to dry out. Yet the rest of the house has gone off before the house is vacated, leaving only the bathroom on for that bit of extra time. Then in the evening at home time the bathroom comes on again but only to 18 degrees - warm enough for a pit stop but not wasting energy heating to 20 or 22.

Likewise the kitchen comes on to 20 degrees in the morning for a nice cosy breakfast time but only comes on to 18 degrees at home time so that oven heat doesn't overheat the room.

The hallway comes on to 20 in the early evening but drops back to 18 at 8pm by which time we are in the living room with the door closed. The bedroom is off (5 degrees) both when the house is empty and during the day, but is then scheduled to 18 degrees from 9pm to 11pm and 14 degrees through the night, then back to 18 degrees for about 7am.

It really is great that we can sit comfortably in the living room knowing that at the right time the bedroom radiator will come on and get the bedroom warmed up for bed time while the living room continues to run, or that the hallway sets itself back a few degrees once we are settled in the living room.

Some of the things our schedule does would take a lot of manual running around with conventional manual TRV's and some things would be impossible. (Like leaving the bathroom at 22 degrees for half an hour when leaving the house only to have it come back on at 18 in the evening)

Being able to monitor and control the system from my phone is great - I will fully confess to adjusting radiators from the sofa using my phone when I'm holding a baby, or turning the heating on or turning the bedroom up a bit higher on a weekend morning without getting out of bed!

Although Honeywell disappointingly, don't provide any way to graph your room temperatures and set points, there are a number of 3rd party pieces of software that can be used to do this - so I have graphs of the temperatures of all my rooms which I find quite useful in monitoring the operation of the system.

I think one thing to keep in mind with any zoned system and trying to achieve gas savings is that (a) you have to have some rooms that are unused for significant periods of time, such as spare rooms, study, spare bedroom etc that you can turn off and (b) you have to try to keep doors to unused rooms closed. If all your rooms are in use most of the time and/or you tend to leave the doors to unused rooms open you might not see much in the way of savings.

I'm constantly closing the doors in the hallway to try to make the most of this (as there are two largely unused rooms off the hallway) but I seem to be fighting a losing battle on this front!

[HenGus]

My wife, like yours, is struggling with the system, and wants to go back to simple controls.

My third Winter and my wife is also having issues coping with Evohome. My other worry is the number of small but annoying issues that arise which I can deal with but my wife could not. For example, a couple of nights ago, we had a loss of comms on one HR92 sensor - the first since the system was installed ( yes, the batteries/contacts are fine). It is one of those annoying faults that might just be one of those things or it could indicate a failing HR92. I now have enough knowledge to monitor the system and, if necessary, switch the HR92 to my hallway where the Evohome acts as sensor or just replace the HR92. She would have no option but to call the installer who would no doubt scratch his head and do little for a dollop of cash. (I am assuming here that my dear wife knows how to find the fault log).

AFAIK, all savings quoted for heating controls are based on the University of Salford Test House results. The 40% figure was based on a property that has no heat controls. I am about 18% pa down in kWh gas usage on my pre-Evohome figure. My guess is that some of this is down to 2 mild Winters.

[DBMandrake]

I don't really understand why so many people have problems with their significant others struggling with operating the Evohome ?

I can see that programming schedules is something would take a little bit of technical understanding - not because the interface is confusing as such, but simply because the concept of having a set point schedule instead of an on/off schedule and then multiplying it by having a separate schedule for every room is something completely new to people used to turning the heating on or off with a master timer or single wall stat, and manually adjusting a TRV from 1 to 5 to make the room "hotter" or "colder" with no real understanding of what the temperature might actually be.

This is a bit of a paradigm shift and even as a pretty technical person it took me many weeks to work out the schedule that suited us for comfort and convenience, fine tuning it as I realised certain rooms didn't need to be hot at these times of day, finding what temperature was comfy in the living room, in the bedroom etc.

However once the system is set up and scheduled it's more or less set and forget - it's left "on" all the time to run its schedule, except when we leave the house on a weekend where we manually turn it off since the weekend schedule has several rooms on during the day.

I wouldn't expect my girlfriend to do all the programming of schedules etc, we do discuss some aspects of the schedule but its up to me to program it which I'm fine with, I don't really want her fiddling with the programming anyway.

However a significant other should be able to deal with turning the system on and off and overriding individual zones, and I don't see what the fuss is there ? Overriding the temperature in a room really is as simple as touching the name of the room on the screen, pressing some up or down arrows to set a new temperature, optionally changing the override time then pressing OK. Job done. What is so difficult about that ?

For those that don't like using touch screens you can walk over to any radiator, turn a nice knob on the top, and read the temperature adjustment on a nice back-lit display as you do so. How is this any harder than turning a manual TRV ? Setting a manual TRV somewhere between numbers is all guesswork (and even the indicated number positions are somewhat guesswork when it comes to what temperature you will get) versus a current temperature reading and a set point that is in actual degrees C. You quickly learn a comfortable temperature is something like 20 instead of "3". I really don't get the techno-phobic attitude that so many people have - I see it all the time at work in relation to basic use of computers etc...

I was asking my girlfriend last night how she finds controlling the Evohome now that we've had it about a year - and believe it or not in a year we've never really discussed it that much, she just gets on with using it. Three points were noted though:

1) From time to time she grumbles about the fact that to turn the heating on you have to "cancel the heating off quick action" instead of just having an option that says turn heating on. This is particularly obtuse on the iPhone app, not quite as bad on the controller itself. And you know what ? I actually agree with her on this point - it is quite obtuse and inside out to describe it as "cancelling the heating off quick action" instead of just having something that says "turn heating on". Because we seldom manually use the heating off action (letting the schedule do its thing) and when we do its usually me that does it, she does actually forget how to turn it back on via the iPhone app because of the obtuse way in which it is described.

2) It took her a while to get used to how much to adjust temperatures if she was a bit cold or a bit too hot. If it was set to 20 and she felt a bit cold instead of turning it up to 21 she'd turn it up to 22 or 23, then half an hour later with the radiator red hot she'd be sweltering and turn it way down again to something like 17, and then a couple of hours later be cold.

Like most people she had the mind set that if you turn a thermostat up really high it will heat up a lot faster which simply isn't true. And she didn't have a good grasp of what one degree of temperature increase felt like (after being used to the arbitrary 1-5) hence over correcting. After a lot of gentle reminding to only make a small adjustment of no more than one degree at a time when she'd say it was a bit cold or a bit hot and then wait to give it a chance to react, that problem seems to be solved. Now she has the hang of making smaller adjustments we haven't had any wild over corrections of temperature...

3) A lack of understanding of whether a zone that is "on" is actually using any gas or not. Many was the conversation in the early days of "why is the living room on when its not that cold" - for example it would say 20 for the set point in the living room and 20 for the current temperature - to which my response would be "touch the radiator - is it hot ?" - "No, it's cold". As the weather warmed up during the day the radiator would shut itself off because no heat would be needed to maintain 20 - so even though the set point and current temperature both said 20 like they had since the morning when the radiator was on, now the radiator was off. All automatically.

It's a bit hard to let go and trust the system partly I think because manual TRV's don't cope well with rooms that are warm enough due to increasing temperatures outside so you do actually have to turn them down somewhat manually or turn down your wall stat to turn off an unnecessarily firing boiler. (At least with a non TPI wall stat) It is a bit of a paradigm shift and I think she probably just gave up arguing with me about it and started to trust the system.

(Honeywell could do a bit more to re-assure owners on this point by *ahem* adding a heat demand indicator to the individual zones on the controller display so it can be seen which zones are and aren't calling for heat and whether its a small, moderate or large call for heat...)

But as far as actually operating the system day to day like making manual overrides in zones I asked her if she had any difficulties with that and she said no not at all, she finds it quite easy to use, and apart from doing things like turning the bathroom up manually when having a shower at an odd time of the day or turning a radiator up for clothes drying I don't actually see her needing to override the schedule manually that often anyway as our schedule is dialled in really well.

Just my 2p worth.

[paulockenden]

Perhaps your girlfriend uses IT stuff at work? Perhaps she uses a smartphone? Perhaps she just has an aptitude for technology?

I think Evohome is a steep learning curve for people where the answer to all of these is no.

P.

[HenGus]

It's probably an age and use thing. My wife and I are in our mid 60s, and as far as Evohome is concerned my wife doesn't need to fiddle with it: that's my job! From time-to-time, we have a little session of refresher training!!

[MichaelD]

Some great views here on the EvoHome system. If saving fuel is your primary concern, then you can schedule for that, or if you want comfort, then you set the schedule for comfort. Most of us want both, and probably achieve the right compromise that works for us.

I love the fact that every room is perfectly scheduled for the way we use it throughout the week, and actually like to feel its cold in the dining room if I go in there during the day, it shows we aren't wasting fuel.

My wife doesn't ever seem to think about the heating, its always right for us, unless we change schedule, like taking a half day off work, but that is just the same as in the old days of a single thermostat switching the entire house on and off. Except now she can choose which rooms to turn on.

Its a different story with our teenager, he refuses to put in the effort to understand things, so just doesn't know how a thermostat works. He thinks if its cold, then he'll set the temperature to maximum and that will make the boiler work harder. Then when it gets uncomfortably hot, he'll leave the thermostat on maximum and open the window. After trying to explain that the boiler doesn't work harder if you ask for a stupidly high temperature, and having him ignore me, I set his thermostat to a maximum of 22, and the problem has gone away.

We have also had a problem with him unplugging things, without any understanding of what the result will be, and the EvoHome provided a brilliant payback. Last December, we had gone away for a few days, and he had the place to himself. So, with nobody to nag him about unplugging stuff, he took out a random plug and plugged in his phone charger. Two days later, he texted us to ask why it was freezing cold in the house. I called him, and we worked through the problem, first, I asked him to check the screen on EvoHome controller, he couldn't do that, because the screen was blank ... Yes, he'd unplugged the controller, and endured two days of freezing cold as a result. Karma. So the system is dependant on the controller working, but there was ever a problem with that, there is a manual fallback, and that is the override button on the boiler relay, so this is a really well thought out system.

[DBMandrake]

Perhaps your girlfriend uses IT stuff at work? Perhaps she uses a smartphone? Perhaps she just has an aptitude for technology?

I wouldn't say she has a particular aptitude for technology, no.

I think Evohome is a steep learning curve for people where the answer to all of these is no.

But again I ask - what is so hard about adjusting an HR92, and why would this be harder than turning a manual TRV ? Where is the steep learning curve for that ? Honest question...

What else do other less technical family members need to do other than turning the whole thing off or on when leaving and returning to the house or overriding the temperature in an individual room ?

Not everyone in a house needs to know how to configure and set up Evohome, nor understand how to program the schedules. All they need to know is how to turn it off and on, perhaps make use of quick actions (which you yourself have argued for keeping as simple as possible in another thread while I find them a bit too limited) and adjust the temperature of a zone, which can be done with a good old fashioned knob by the radiator if preferred. Just saying...

[paulockenden]

Adjustments on my HR92s are disabled because zones kept getting set to stupid temps during cleaning.

Don't know whether others have found this?

P.

[DBMandrake]

Adjustments on my HR92s are disabled because zones kept getting set to stupid temps during cleaning.

Don't know whether others have found this?

P.

Nope haven't had that - the knobs are pretty slippery so don't seem to be accidentally turned.

I have had some HR92's knocked by moving furniture so that they turn around on the thread of the radiator though - I have the display angled out with the support wedge on most of them but this is a good thing to hit when a table or similar is dragged nearby. In one case the screen was ripped right off - I had to disassemble the whole thing (which is fairly tricky) so that I could reconnect the ribbon cable! Luckily the cable wasn't damaged, it was just pulled out of the socket.

Because of this in the hallway where the risk of kicking is high I have the HR92 oriented with the screen parallel to the wall rather than sticking out as most others do...

I dread the day when our little one is old enough to be ramming toy trucks into the side of the radiator valves - I'm not sure how well they'll stand up to that, at least with the screen extended! (And no doubt I'll have to lock the local overrides on them all as well so that only grownups can adjust the temperature )

[paulockenden]

Also, my wife typically wants to 'turn the heating down' - to her 'the heating' is still a thing. When rads aren't on (because the room is up to temp) she asks me why 'the heating' is off.

And zones become very confusing when you turn down the temp on one HR92 and it also affects other radiators in the same zone. The logical thing when adjusting the temp on a rad is that THAT rad gets turned down.

I know we probably all scoff and laugh at people that don't get it, but it IS a problem. And I echo the comments further up the thread about how she'd cope if I wasn't around for any length of time.

Don't get me wrong - I'm not anti-Evohome. Far from it. I'm a big fan. But I think we have to be honest and accept that there IS a big usability problem for some people, in terms of the concept of zoned heating, the concept of scheduled heating, the controls, and the ongoing maintenance of the system. If there was just one of us facing this problem at home you could perhaps dismiss it, but this thread shows that this isn't the case.

[bruce_miranda]

The wife and kids have long realised that only Daddy knows how to operate the heating. But add my plumber to the list as well. He has no clue where to every start.

[g6ejd]

I think some (mainly females - there I said it) would keep turning the heating up until a room became sub-tropical then suddenly realise it's too hot then turn things down, then the process might start over again I also think temperature acclimatisation occurs over time leading to a gradual increase in set temperatures. Luckily the Evohome system can cope with all that and a has a solution for most scenarios - I think I'll now go and disable local overrides :0