Honeywell evo home - minimum needed?

[pilsbury]

In the middle of purchasing a 1930s solid wall 4 bed detached. Has a lot to do which includes a new boiler install.

Going for a combi - Worcester or Valliant and am still deciding on what thermostat set up to get. Single zone programmable is obviously cheapest, but then I got onto the nest type ones, that to me just seem like internet/mobile phone connected single zone things. Like them for the gizmo factor, but can't see they are a leap in economy.

The evohome does seem to have this, but for a price - a hefty price. I've got the general jist of it - a magic TRV in each room that opens and closes the valve just as required to reach the exact temp. If all are closed, the boiler is turned off. If only one needs heating, the boiler is told to just heat a little bit. All controlled centrally by the controller or your mobile app. Correct? I like the idea of each room being independently heated (or not) throughout the day. Seems a big forward step.

But as I said it costs - I have a few questions for those who have a set up and those in the know.

Some of my rooms have 2 rads. Does each rad need one of the special TRVs?

Does every room need to have the special TRVs installed or can you just zone all the bedrooms from one room with one special TRV? How does it shut the rads down in the other rooms in this case?

I recon it would cost me damn near £1.2K to get a full system. Is this all needed at once or is there the basics that would make a difference to start with that can be added to?

On a similar note, is this an all or nothing system to get decent economy benefits?

How much do you recon it is possible to save per year if you set it up efficiently over a single zone programmable thermostat?

Thanks for the thoughts

 

[flameport]

Going for a combi

In a 4 bedroom house? Suggest you reconsider.

As for the rest - yes you can buy various parts of the system and add others later as desired.
If you want individual room control, then you need a radiator controller for each room.
However the system can control other items including normal zone valves if you want a zone consisting of several rooms.
All details here: http://connectedproducts.honeywelluk.com/evohome/plan.php

 

[pilsbury]

Thankyou - why reconsider? Overkill for a 4 bed house?

 

[flameport]

Combination boilers can supply one hot water outlet at a time. Suitable for small properties with low hot water requirements.

 

[pilsbury]

Right - you're talking about the boiler as opposed to the evohome.....

 

[bernardgreen]

Combination boilers can supply one hot water outlet at a time. Suitable for small properties with low hot water requirements.

And being sized large enough to heat water fast enough for a shower they are then very much oversized to supply the small load to heat the house. This can result in a condensing combination boiler being less efficient at heating the house than the boiler it replaced, especially if the radiators are not changed ( enlarged ) to allow them to heat the rooms with lower temperature water in the radiator circuit .

Due to the high temperature in the water returning from the radiators the condensing boiler is not always able to operate in condensing mode when in heating mode and thus can be ( far ) less efficient than it's rating suggests. When heating cold mains water the boiler can operate in condensing mode and can then be as efficient as is claimed.

 

[pilsbury]

Combination boilers can supply one hot water outlet at a time. Suitable for small properties with low hot water requirements.

And being sized large enough to heat water fast enough for a shower they are then very much oversized to supply the small load to heat the house. This can result in a condensing combination boiler being less efficient at heating the house than the boiler it replaced, especially if the radiators are not changed ( enlarged ) to allow them to heat the rooms with lower temperature water in the radiator circuit .

Due to the high temperature in the water returning from the radiators the condensing boiler is not always able to operate in condensing mode when in heating mode and thus can be ( far ) less efficient than it's rating suggests. When heating cold mains water the boiler can operate in condensing mode and can then be as efficient as is claimed.

So what is the suggestion then? What would be the ideal boiler install for a fairy big 4 bed property?

 

[flameport]

Any heat only or system boiler with an unvented hot water cylinder of whatever size is appropriate for the expected hot water requirements.
Or vented cylinder & pump if the mains pressure & flow are unsuitable for an unvented type and the water supply can't be upgraded.

 

[bernardgreen]

As Flameport has said, a heat only boiler and a hot water cylinder to supply bath, basins and sinks with hot water. For the shower mains pressure water (*) is heated by passing through a second coil in the hot water cylinder.

This avoids the need for any pumps. A vented cylinder avoids the need for the safety devices and routine testing of them that are necessary for the safety of an un-vented cylinder
(*) a word of caution. Showers fed with un-regulated mains pressure water can provide a stimulating massaging flow but can also be damaging to the skin and eyes when the mains supply pressure is very high.

 

[muggles]

As above, a combi would be totally unsuitable for your property - a system boiler and unvented cylinder would be best (assuming your mains water supply is sufficient). Ignore Bernard, he has an unfathomable aversion to unvented cylinders. As for boilers, look at Intergas - up to ten years warranty, has just won Product Of The Year at the recent industry H&V Awards, and isn't built from rubber and plastic. Also OpenTherm compatible, which will make it more efficient on an EvoHome system, or with other OpenTherm controllers (Wooshitter Bodge and Faillant aren't OT Compatible),

As for Evohome itself, you can start with a basic system then add to it later if you want, although setup is simpler if it's all done together. If you're going for the TRV controllers, all rads in a room should have the controllers or you lose the functionality. I'd advise getting a signal test done before you buy Evohome - reception can be a bit rubbish

 

[Lexden]

Let me try and help the OP. I installed Evohome nearly 2 years ago with TRVs on all radiators along with the HW kit.

Firstly, it is possible to build the system; however, the disadvantage of having a combination of HR92s and manual TRVs is that the rooms with manual TRVs will always come on when an HR92'd zone calls for heat. This is only a decision that you can make.

Secondly, Evohome communicates with its components using 868MHz wifi. I live in a large 5 bed house and I have had no issues with wifi connectivity between the EvoTouch controller and the wifi TRVs. I had had comms faults between the controller and the CH and HW boiler demand relays (BDR91s) located in my airing cupboard. The installation requirements are very precise (i.e., minimum distances between relays and other metal/electrical components). Once my installer relocated the BDRs, the issues that I was experiencing stopped.

Evohome is easy to set up and easy to use. You can have heat wherever and whenever you need it. For convenience (and safety), I have wall-mounted my Evotouch in my hall. The controller itself can be used as a zone temperature controller. In rooms where there are more than one HR92, the zone can be configured as a single zone with the first bound HR92 acting as the temperature sensor (you need to think about this as it is best to avoid using the HR92 as a sensor when it is located behind furniture, curtains etc) or the the zone can be configured multi-room with each HR92 doing its own thing. HR92 batteries last about 2 years in normal use.

The new wifi controller connects directly to your router. The app is adequate and it has just been updated. Honeywell can 'push' firmware upgrades to the Evotouch.

Now we come to savings. Honeywell et al will claim 'Up to 40%'. Of what is the question? The truth is that these claims were based on an university study where a 3 bedroomed property was built in a climate-controlled chamber. The 40% saving ( on energy used not billing) was based on smart controls being installed in a property with NO heating controls. Most properties have some heating controls (timer, thermostat etc).

Looking back over the past 2 years, I have saved about 17.5% of my total gas (kWh) consumption. Evohome replaced a conventional timer, hall stat and TRV set up. The real benefit, however, is that we now keep the rooms that we use at living temperature. For example, our bedroom and ensuite are warmed in the morning but off during the day followed by 90 minutes heat just before we settle down for the night.

If you want to know more about Evohome, I recommend that you look at this forum which is supported by Honeywell UK:

http://www.automatedhome.co.uk/vbulletin/forumdisplay.php?13-Heating-Control

Would I buy Evohome knowing what I know now? Yes, for the convenience/benefits but not for the savings.

PS. Battery-powered HR92s do whirr in operation. The noise is not intrusive, but it would be daft to say otherwise. There can be an occasional clunk if the TRV valve itself is a little sticky. If you set optimum settings, then the whirrs and clunks can come at different times depending on how cold the room is.

 

[andymet87]

Would I buy Evohome knowing what I know now? Yes, for the convenience/benefits but not for the savings..

Sorry for hijacking this old thread but I have a question for Lexden...

I'm in the process of renovating a 4 bed property that is very old (first written record of the house is in 1770) and have specified the full Evohome system to all plumbers for quotes (underfloor heating downstairs and wifi TRV's upstairs). Just had one plumber phone me up and say it's a useless system that rarely works as it's meant to... I like the idea of a central control panel (we'd put in in the hall) where I can control everything from and it is mainly for ease of use and using less fuel rather than £ savings.

Obviously your system seems to work well which is great, do you know of anyone else with the system working well? How hard was it to iron out your initial issues ?

 

[Lexden]

Would I buy Evohome knowing what I know now? Yes, for the convenience/benefits but not for the savings..

Sorry for hijacking this old thread but I have a question for Lexden...

I'm in the process of renovating a 4 bed property that is very old (first written record of the house is in 1770) and have specified the full Evohome system to all plumbers for quotes (underfloor heating downstairs and wifi TRV's upstairs). Just had one plumber phone me up and say it's a useless system that rarely works as it's meant to... I like the idea of a central control panel (we'd put in in the hall) where I can control everything from and it is mainly for ease of use and using less fuel rather than £ savings.

Obviously your system seems to work well which is great, do you know of anyone else with the system working well? How hard was it to iron out your initial issues ?

Have a look at the Automated Home website: there are many, very happy users of the Evohome system. My advice would be to look for a plumber that is an accredited Honeywell Connected specialist. Without training, the average plumber is unlikely to understand some of the potential installation issues. For example, it is very easy to double bind a Boiler Demand Relay without realising it, and minimum distances are crucial. Evohome UK has a support team based in Bracknell who are very good. Furthermore, The Evohome Shop offers full support if you purchase from them. They will for a small price pre-bind the BDRs and HR92s to make installation easier. To answer, your specific question, it took about a year to solve my issues once Honeywell accepted that having tried everything else, it was trobalt an Evotouch issue.

I have recently traded in my Mark 1 Evotouch for the new wifi controller and have had no issues. I managed to do the re-install myself without any problems. There are some very good online videos.

In sum, get someone who has had Honeywell Evohome training and has actually installed the system. A trained installer has full access to Honeywell if there are any issues.

Finally, just a thought. If your 'project' has thick stone walls, you would be all advised asking a potential installer to carry out a survey before you commit. Sadly, Honeywell has yet to produce a wifi extender and even using the 868 band there have been reports of issues in older properties.

 

[andymet87]

Thanks for your thoughts and speedy reply! - will see if I can find a local accredited plumber...

re walls, our situation is quite the contrary! Walls aren't that thick, out of interest how does it work, do all the TRV's etc connect to the main controller that is in turn connected to the boiler or is there a seperate controller near the boiler. The plan is for the controller to be in the middle of the house on the assumption everything would talk to that, and the controller then controlled the boiler etc...

did that make sense?

 

[Lexden]

Thanks for your thoughts and speedy reply! - will see if I can find a local accredited plumber...

re walls, our situation is quite the contrary! Walls aren't that thick, out of interest how does it work, do all the TRV's etc connect to the main controller that is in turn connected to the boiler or is there a seperate controller near the boiler. The plan is for the controller to be in the middle of the house on the assumption everything would talk to that, and the controller then controlled the boiler etc...

did that make sense?

This might help. You can sign up as an individual:

http://youlearn.honeywelluk.com/courses

I have a conventional boiler in an 'S' plan configuration with an unvented cylinder. To keep things simple, I have retained both motorised valves which are connected to 2 BDRs in the airing cupboard. All HR92s communicate directly to the EvoTouch controller. Each HR92 can act as both a sensor and actuator; however, it is usual in a multi HR92 room to have one HR92 act as the sensor. The Evotouch controller can also act as a zone sensor.

When a zone demands heat, then a signal is sent to the BDR which operates the CH isolation valve. The CH isolation valve can be removed (or wired open) and the HR92/EvohTouch can be used to provide a direct link to the boiler. My HW is controlled via a sensor linked in series with the two unvented tank stats to activate the HW BDR and open the valve etc. HW can be controlled in the range set temp - 10. Various configurations are shown in the link.