Results 1 to 2 of 2

Thread: Evohome strange issue

  1. #1
    Automated Home Jr Member
    Join Date
    Mar 2018
    Posts
    13

    Default Evohome strange issue

    Evening,

    So, ive had the evohome system for over 2 years trouble free. Yesterday an issue occurred:

    - 1 Room didnt fire to the schedule, lets refer to that as living room, all other rooms fine (i have 7 TRVs in total)
    - Now with that room i cannot get the TRV to work in conjunction with the call for heat. If i do an override on the evohome controller it changes on the screen and on the TRV screen to the requested temp, calls for heat say at 100% on the boiler and shows the same on the TRV (in the controller menu)

    I had a spare TRV so i swapped it out, unbound and re bound the new one successfully - RF comms are strong with both the TRV and the BDR91. Same issue. All displays show its working but no heat.

    If i hold the radiator pipe, its hot but no heat in the radiator. If i then remove the TRV and twist the black dial manually fully open, the radiator heats up :/ - ive requested upto 35 degrees so should definitely fire over room temp

    The valve isnt stuck, the TRV is fine as i have also tested on another radiator which is actually working.

    An issue just started this evening is that any override on the controller is showing a call for heat, changing the TRV but no heat is generated at all so the boiler isnt firing. Just happened the once - seems to be taking an age to influence the boiler (again RF comms is strong)

    Its a pain this one, anyone any ideas - im thinking next steps may be to factory reset and rebind from the beginning

    Probably makes little sense as its confusing me so no doubt the above will confuse everyone else :?

    Any help is appreciated

    Thanks in advance

  2. #2
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,843

    Default

    Quote Originally Posted by Jamesw6810 View Post
    - 1 Room didnt fire to the schedule, lets refer to that as living room, all other rooms fine (i have 7 TRVs in total)
    - Now with that room i cannot get the TRV to work in conjunction with the call for heat. If i do an override on the evohome controller it changes on the screen and on the TRV screen to the requested temp, calls for heat say at 100% on the boiler and shows the same on the TRV (in the controller menu)

    I had a spare TRV so i swapped it out, unbound and re bound the new one successfully - RF comms are strong with both the TRV and the BDR91. Same issue. All displays show its working but no heat.

    If i hold the radiator pipe, its hot but no heat in the radiator. If i then remove the TRV and twist the black dial manually fully open, the radiator heats up :/ - ive requested upto 35 degrees so should definitely fire over room temp

    The valve isnt stuck, the TRV is fine as i have also tested on another radiator which is actually working.
    You say the valve isn't stuck, but to me this sounds like a problem with the valve body, and a similar problem to what I have experienced, where they wouldn't start flowing until the pin was nearly all the way out. What kind of valve bodies do you have ?

    When you turned the black wheel, how far did you turn the wheel from the point where the HR92 thought it was fully open ? Less than a full turn ?

    As a test, I'd suggest setting the HR92 Stroke setting to 1 - this increases the range over which it moves the pin and is necessary for proper compatibility with some valve bodies. After changing the setting, remove the HR92, turn the black wheel anti-clockwise and refit the HR92 so it can calibrate itself again.

    If that helps it suggests that either the valve body has gone faulty, (sticky) or was never fully compatible with the HR92 in terms of pin travel vs flow.

    It's a long read but you might want to read my thread here for a description and diagnosis of a similar problem:

    https://www.automatedhome.co.uk/vbul...light=valencia

    In the end I found setting Stroke to 1 worked the best with my Valencia valve bodies.

Posting Permissions

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