Results 1 to 10 of 10

Thread: can I have a bit of advice please? Evohome

  1. #1
    Automated Home Lurker
    Join Date
    Jan 2019
    Posts
    8

    Default can I have a bit of advice please? Evohome

    Hi all,

    I've read the forums as well as I can but I'm a bit of a newbie at this and I would really appreciate some pointers.

    I'm doing a house refurbishment with a new extension. 1920s construction, internal insulation of external walls on the old bit with normal radiators everywhere apart from one cast iron reclaimed rad and two sections which have tiles where I'm having electric underfloor heating, new extension brick and blockwork with underfloor everywhere. It'll be quite sizeable (6 bedrooms and 4 reception rooms plus an entrance hall). I have some questions which I'd be super grateful for help with.

    Electric underfloor:

    In the family bathroom I'm also having a water towel rad which I was planning on having an HR92 to control the towel warmth and general room warmth. the idea of the electric underfloor is to have warm tiles but not really for the whole room. Can I connect the electric underfloor to my system easily? Can I group it in some easy way with the TRV? any other considerations?

    In the garden room, which is to be tiled, I'm having electric underfloor and it has an open archway to the garden room which has a radiator and hr92. again, can I control all with evohome and can they link somehow?

    Finally, I was considering putting it in the entrance hall which is of course continuous with the landing and the stairs. there are rads up and downstairs. can I use it in some way just to have a nice warm floor for coming home?


    Cast iron rad:

    I'm assured that the TRV will work with it. if it didn't, can you have a rad with a manual try in an evohome system. doesn't that mean heat would have to be running the whole time whereas if all the TRVs were off and all electric the boiler would know to switch off. sorry I'm totally clueless about this!!!

    Wet underfloor system:

    If I'm having a system boiler with two 200litre tanks, which bits do I need? do I need 2 hot water controllers? Also, should I ask for opentherm or is that irrelevant with hot water tanks?

    finally, the boiler and tanks are going to be in the garage and because the place will be quite big when finished, I'm wondering if signal will be good enough all over the house. does it piggy back on normal wifi? I'll have two controllers because more than 12 zones, do they repeat and mesh in some way?

    finally, finally, the system seems quite old now, are we due an upgrade and should I wait a few months before taking the plunge?

    thanks so so much!!!

  2. #2
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,844

    Default

    Quote Originally Posted by bigrw View Post
    Electric underfloor:

    In the family bathroom I'm also having a water towel rad which I was planning on having an HR92 to control the towel warmth and general room warmth. the idea of the electric underfloor is to have warm tiles but not really for the whole room. Can I connect the electric underfloor to my system easily? Can I group it in some easy way with the TRV? any other considerations?
    I don't think you can have HR92's and Electric heating elements in the same zone in an Evohome config. When you create a zone you have to choose between "Radiator Controller" or "Electric heating zone" (or a few other choices) with no way to choose both. So I suspect the underfloor would have to be configured as a separate zone. You can of course schedule the two zones to have the same schedule, although it will eat into your 12 zone limit.
    In the garden room, which is to be tiled, I'm having electric underfloor and it has an open archway to the garden room which has a radiator and hr92. again, can I control all with evohome and can they link somehow?
    Same problem here, two separate zones eating into your maximum zone limit of 12.
    Finally, I was considering putting it in the entrance hall which is of course continuous with the landing and the stairs. there are rads up and downstairs. can I use it in some way just to have a nice warm floor for coming home?
    If you have a hallway with both ground floor and first floor radiators in what is basically the same air space then yes, this shouldn't be difficult as you can have multiple radiators in the same zone and it still only counts as one zone and has one schedule.

    Normally with a multiple radiator zone there is only one sensor - either a wall sensor, or one of the HR92's is nominated to be the temperature sensor for both radiators. However due to the height difference you'd probably find it was a lot hotter upstairs than on the landing, as the heat from both radiators would heat the landing (heat rises) but the top floor radiator would only heat the top floor. Regardless of which you chose as sensor you'd probably get a big temperature difference.

    What I would probably do is configure the zone as a "multi-room zone" when creating it. This tells both HR92's to use their own internal temperature sensors. They share a schedule but measure and adjust themselves separately. So when your hallway schedule says 20C, both radiators will try to adjust themselves to achieve 20C on their floor. This will probably result in the ground floor radiator doing more work than the top floor one, but the end result should be an even temperature at both levels.
    Cast iron rad:

    I'm assured that the TRV will work with it. if it didn't, can you have a rad with a manual try in an evohome system. doesn't that mean heat would have to be running the whole time whereas if all the TRVs were off and all electric the boiler would know to switch off. sorry I'm totally clueless about this!!!
    Can't see any reason why an HR92 can't control an old cast iron Radiator. If you can get a valve body with a fitting compatible with the HR92 it will control it. By default the HR92 supports M30x1.5 valve bodies so a M30x1.5mm valve body that is compatible with the cast iron radiator (1/2" pipe ?) would be the best option but adaptors are available for the HR92 to fit other fitting types.
    finally, the boiler and tanks are going to be in the garage and because the place will be quite big when finished, I'm wondering if signal will be good enough all over the house. does it piggy back on normal wifi? I'll have two controllers because more than 12 zones, do they repeat and mesh in some way?
    No piggybacking on wifi, no mesh repeating I'm afraid.

    The controller is central to the system - every other device talks only to the controller so the controller should be centrally located for best signal preferably on a wall mount if the property is large. If you have two controllers you effectively have two independent systems in the house that just share a common boiler. The devices belonging to one controller will talk only to it, the devices belonging to the other controller will talk only to it. Generally only one controller will be responsible for hot water in a two controller system however if you have two separate cylinders that are under separate control you may want hot water control with both as each one can only control a single hot water cylinder.

    If the property is large and some devices are in a garage signal strength could be an issue.

    A large property with potential signal range/coverage issues and a dual controller installation would both really need someone who knows what they're doing with the installation as there could be some complications. Are you trying to install it yourself or do you have an Evohome aware installer doing the job ?
    finally, finally, the system seems quite old now, are we due an upgrade and should I wait a few months before taking the plunge?
    Yes it is getting a bit old now. I bought the Evohome wifi controller 3 1/2 years ago and it's still the current model. There have only been 2 or 3 minor firmware updates in that whole time.

    Nobody knows if/when the controller will be updated - we'd all like to know as well!
    Last edited by DBMandrake; 16th January 2019 at 04:50 PM.

  3. #3
    Automated Home Jr Member
    Join Date
    Jan 2019
    Posts
    15

    Default

    Quote Originally Posted by bigrw View Post
    Hi all,
    finally, the boiler and tanks are going to be in the garage and because the place will be quite big when finished, I'm wondering if signal will be good enough all over the house. does it piggy back on normal wifi? I'll have two controllers because more than 12 zones, do they repeat and mesh in some way?

    thanks so so much!!!
    I can't help with anything else, but can help on this.

    Get yourself the RF Tester, this will help answer your question. It is stated that the RF signal will travel 30m. However, it will depend on the construction of your house. The signal fails to travel 10-15metres from my boiler to the controller (in the middle of the house), as there are multiple solid walls in between. I had to drill through one of the walls and put the relay boxes in a room closer to the controller to get the things to talk to each other. The relay boxes are only 300mm closer to the controller, but the signal improves dramatically as that barrier is removed.

    There is no piggy backing. The hot water signal device doesn't communicate with the hot water relay (which I thought was happening), it all goes to the controller, then back out.
    There are no repeaters/extenders available on the market currently either.

    If you get the RF Test kit, then this will tell you if it will work in your configuration or not.

  4. #4
    Automated Home Lurker
    Join Date
    Jan 2019
    Posts
    8

    Default

    Thanks so much everyone.

    is the general advice then given that I'm trying to do two electric underfloors to just go with a different wireless electric system and control that separately. I basically want warm tiles from that heating system not a warm room!

    with an RF tester if it fails to get to the furthest radiator does that mean I need to run some cables from further away back to the boiler?


    does anyone else have opinions about the two cylinder thing?

  5. #5
    Automated Home Lurker
    Join Date
    Jan 2019
    Posts
    8

    Default

    I have had a quote for the whole build including all the plumbing and electrics. My electrician hasn't personally installed evohome before. How much would it cost to get a specialist to come and advise on this. or should I even just insist on a specialist doing it.

    is it right that I can hire a test kit? does that allow me to test from boiler to controller and then controller to the radiators?

    thanks so much

  6. #6
    Site Sponsor The EVOHOME Shop's Avatar
    Join Date
    Dec 2014
    Location
    Powys, Mid Wales
    Posts
    479

  7. #7
    Automated Home Jr Member
    Join Date
    Jan 2019
    Posts
    15

    Default

    Quote Originally Posted by bigrw View Post
    Thanks so much everyone.

    is the general advice then given that I'm trying to do two electric underfloors to just go with a different wireless electric system and control that separately. I basically want warm tiles from that heating system not a warm room!

    with an RF tester if it fails to get to the furthest radiator does that mean I need to run some cables from further away back to the boiler?


    does anyone else have opinions about the two cylinder thing?
    You will have multiple pieces of kit, all of which need to speak to the controller. The TRVs are not wired, and so the controller needs to be able to speak to the furthest away TRV - that is most important.
    The relay devices (which are attached to the boiler), are wired, and so as long as you can run cable, then you can move them closer to the controller. In my case, I had to drill through a wall.
    For the hot water sensor, this is a battery operated device, connected via cable, to the sensor which is attached to your hot water tank. The length of this cable is a 1.5 meters, and so if you need to move this device, you would need to buy a junction box, and more cable to move it.
    Depending on how easy it is to drill through walls or run cable, will determine how easy a job it is to install.

    If your signal drops at any point, it can be a MASSIVE inconvenience. My hot water sensor would drop overnight, so I would get up to cold water. The signal strength has to be good otherwise this doesn't work.

  8. #8
    Automated Home Legend paulockenden's Avatar
    Join Date
    Apr 2015
    Location
    South Coast
    Posts
    1,602

    Default

    Quote Originally Posted by uhhu View Post
    For the hot water sensor, this is a battery operated device, connected via cable, to the sensor which is attached to your hot water tank. The length of this cable is a 1.5 meters, and so if you need to move this device, you would need to buy a junction box, and more cable to move it.
    It's a low voltage, and as the sensor is 10kOhms (NTC) you can extend the cable quite a bit without it having any effect in the readings. Wago or even an old fashioned choc-block connector is fine (I used a staggered soldered joint with some heat-shrink sleeve, to keep things neat).

  9. #9
    Automated Home Jr Member
    Join Date
    Nov 2015
    Posts
    22

    Default

    I have set up electric underfloor heating in rooms that have water filled towel rails as their main heating. The electric underfloor is to provide warm feet on cold mornings and evenings at shower/bath time. See my full explanation here: https://www.automatedhome.co.uk/vbul...ll=1#post39450

  10. #10
    Automated Home Lurker
    Join Date
    Jan 2019
    Posts
    8

    Default

    Thanks so much guys this is super helpful!!

    Just out of interest does any have any views on the 2 water tank issue. do I need a separate sensor etc for each? Any advice on how I connect them?

    Rich

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •