Page 1 of 13 12345611 ... LastLast
Results 1 to 10 of 125

Thread: Evohome Opentherm Boiler decision and set up

  1. #1
    Automated Home Jr Member
    Join Date
    Jan 2018
    Posts
    39

    Default Evohome Opentherm Boiler decision and set up

    Hi, Before I begin, can i just say what an excellent forum this is. I have had several issues over the past 6 months regards firstly buying the Evohome, then setting it up with my current boiler set up (Currently Y plan). Now hoping that you guys can help with the next stage of my decision.

    I share a 4 bedroom detached house (medium sized) with my wife (just us for now), having repiped and renewed the radiators I am at the stage where I can finally get rid of the 1986 boiler and open vent cylinder set up. The new set up will consist of a system boiler and unvented cylinder to be relocated to our attached garage using the S plan arrangement in the honeywell instructions with one zone valve to the HW and open CH circuit for the OT - all rads to have HR92's. I have found the heating engineer i wish to use - knowing a few plumbers that have done work for me over the years, this chap is the only one i really trust to do this build for me as he's actually interested in the actual end product rather than just fitting for fittings sake - he also does a great job having seen his work elsewhere.

    The system will consist of a Gledhill 250 litre cylinder which should work nicely with the planned smart showers I will be installing. The problem is which boiler - my heating chap recommends WB (obviously no OT), Viessmann and Vailliant in that order (aiming around the 30kw mark). I have everything to set up my Evohome for OT and plan to go down this route - with my research and based on these boilers all being around the same price, I have discounted the Vailliant given the requirement for the VR33 which tips it over the price point, and based on the fact it is my engineers 3rd choice. Long and short of it is I have narrowed it down to Viessmann or Intergas which my installer has never fitted before. I completely understand the issues with Viessmann with the over shoots/lack of limiter and know this is something i would have to put up with - having emailed Viessmann they have confirmed they are working with Tado to enable Tado to integrate an upper boiler temp limit but this will unlikely affect Evohome as it sounds like they are helping Tado control their boiler as opposed to reinstating their own limiter. The Intergas for me is the easiest option especially given the reviews...

    My installer is understandably not keen on fitting the IG, preferring the Viessmann not least for the 10 year warranty compared to the IG which would only be 3 given he isn't a platinum installer. I have also read that the IG boilers don't do very well in hard water areas and have read many reviews online around failure in this department - where installers have fitted water softeners and they have still failed with no support from IG despite the warranty. The Viessmann rep is suggesting the benefit i will get on OT will be minimal, therefore I should just use the standard BDR91 switching - something I don't really want to do, i want to use my shiny Evohome to its max potential!

    So this is where I am - I want the Viessmann for the warranty, I completely get the Intergas system but with 3 years warranty, it's more of a gamble.

    Can I have some opinions please

    Thanks

    T

  2. #2
    Automated Home Legend paulockenden's Avatar
    Join Date
    Apr 2015
    Location
    South Coast
    Posts
    1,562

    Default

    Quote Originally Posted by 1animal1 View Post
    ...and unvented cylinder to be relocated to our attached garage using the S plan arrangement
    One thing to be aware of is the pipe length / water volume between the stored hot water tank and the kitchen/bathroom taps. If it's too long you'll end up wasting a lot of water, and also a lot of energy. It's a problem we have here.

    P.

  3. #3
    Automated Home Jr Member
    Join Date
    Jan 2018
    Posts
    39

    Default

    Hi Paul, thank you for your reply.

    I had considered a pumped HW ring but given the location of the new system, having a branched system should work and this is the line I will be going down. If for any reason it doesn't I have repiped everything in such a way that a pumped ring could be easily included. The new kitchen requirement is 2 metres away, worst run is the en suite which is about 12-15 metres to what will be the electronic mixer valve.

  4. #4
    Automated Home Sr Member
    Join Date
    Apr 2017
    Posts
    84

    Default

    No contest in my opinion.

    Intergas are built like no other -
    Does Veissmann still have rubber hoses to and from the heat exchanger?
    The intergas would be simple to descale if ever necessary (are you in a hard water zone?) and don't forget that you'll be paying for the ten year warranty of the Veissmann in the purchase price.



    Martin.
    Last edited by blowlamp; 28th January 2018 at 12:02 PM.

  5. #5
    Automated Home Sr Member
    Join Date
    Apr 2017
    Posts
    84

    Default

    Veissmann hoses

  6. #6
    Automated Home Legend
    Join Date
    May 2014
    Posts
    988

    Default

    The Viessmann 100 has OT issues and the 200, AFAIK, isn't OT compatible. If you have a chosen installer, then I suggest that your boiler options are limited. I have an Atag is 24 boiler that is working very well with Evohome/OT on an unvented system. That said, I selected my boiler and then spent a number of months tracking down a reputable installer. The 'is' boiler range comes with a 10 year parts and labour warranty, and lifetime heat exchanger guarantee. There is no additional cost for these warranties. I believe that Atag also do 'on site' installer training. A man with a van pitches up and it has a full sized boiler, shower etc built into it.

  7. #7
    Automated Home Jr Member
    Join Date
    Jan 2018
    Posts
    39

    Default

    Thanks Martin, I had seen that IG video which is what swung it back for me. However it's the warranty that's killing it for me and I really do not want to be changing heating engineers to bring in an IG fitter.

    I did ask the question about the hoses and it appears they do still use them. I can't see the big issue however? If they were solid hoses you'd still have the same problem, or are you getting at the sheer volume of hose in there compared to IG?

    I have bought the Spiro twins for the filtration. Filter and air remover. I've also replaced a lot of the branches from the CH feeds, with speedfit so muck in theory should be minimal.

    Hard water area yes

    I had read about IG never having had a heat exchanger fail, but looking on review pilot, that's clearly not the case. In IG's defence I completely get the design and why the 'old tech' argument is invalid. The fairly high modulation ratio doesn't bother me either. Plug and play too... It's purely support and warranty that's killing it for me. Question, I had read they'd got rubbish pumps in them and they are very easy to replace with off the shelf premium brands, is this the case or would I need a particular pump designed for the IG?

    Correct regards the V... £100 to extend to 10 years warranty.

  8. #8
    Automated Home Jr Member
    Join Date
    Jan 2018
    Posts
    39

    Default

    Quote Originally Posted by HenGus View Post
    The Viessmann 100 has OT issues and the 200, AFAIK, isn't OT compatible. If you have a chosen installer, then I suggest that your boiler options are limited. I have an Atag is 24 boiler that is working very well with Evohome/OT on an unvented system. That said, I selected my boiler and then spent a number of months tracking down a reputable installer. The 'is' boiler range comes with a 10 year parts and labour warranty, and lifetime heat exchanger guarantee. There is no additional cost for these warranties. I believe that Atag also do 'on site' installer training. A man with a van pitches up and it has a full sized boiler, shower etc built into it.
    It was the 100w I am considering even with the issues. My current boiler spits out similar temps of 80 odd degrees without any issues of scalding via the closest rads. Other issue is the 2 or 3 degree over spikes which I could live with as the rooms are heated in prep for using them. So not the most efficient but once passed start up phase and using OT. I'd be good to go no?

    Very interesting with the ATAG. My chap thought you had to be an approved installer before you could fit or indeed source... I'll have a look at this option. Are these very much plug and play like the IG?

    How did the cost of the is24 compare to other brands?
    Last edited by 1animal1; 28th January 2018 at 01:20 PM.

  9. #9
    Automated Home Legend
    Join Date
    May 2014
    Posts
    988

    Default

    Atag will only supply to GSR engineers. The GSR engineer does not have to be Atag approved; however, the warranties are based on an approved installer. I would say that there is a premium cost to this boiler but as I had additional work done on the system including a 2 day/19 radiator flush and the installer had some distance to travel, I was content. In truth, he was the only one that I found that understood Opentherm. That said, he wasn’t familiar with Evohome so I had to make the 5 minute set up change to my existing controller.

    As I have posted before, the boiler temperature limit (TSet Max) is set in the boiler profile. Whether it be hot water or CH, the TSet Calculated never rises above TSet Max. Manual CH max temperature control is inoperative under Opentherm control.

    There is an installation guide on the Atag website.

  10. #10
    Automated Home Jr Member
    Join Date
    Jan 2018
    Posts
    39

    Default

    It is very unfortunate but I see the thinking behind it. I suppose from a fitter perspective you'd have to want to move and take the course. Bit of semi blind faith.

    Are you saying you can't control your upper limit on the CH or are you referring to Viessmann

Posting Permissions

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