1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Vaillant Ecotec Plus 430 Open Vent - Pump Overrun - Required?

Discussion in 'Plumbing and Central Heating' started by craig1234, 1 Apr 2016.

  1. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    63,560
    Thanks Received:
    4,511
    Location:
    London
    Country:
    United Kingdom
    Yes, Bunny, that's what they say. But user's experience seems to be different.



    I would always fit a pump over run as it reduces thermal stress and theoretically slightly increases the efficiency.
     
  2. Sponsored Links
  3. D_Hailsham

    D_Hailsham

    Joined:
    18 Oct 2007
    Messages:
    10,444
    Thanks Received:
    1,315
    Location:
    Kent
    Country:
    United Kingdom
    Not sure how you would do that if the boiler doesn't have connections for a pump.
     
  4. craig1234

    craig1234

    Joined:
    17 Nov 2008
    Messages:
    65
    Thanks Received:
    2
    Location:
    Kent
    Country:
    United Kingdom
    My existing setup consists of three interconnected relays which allow either my original or extension "systems" to provide pump overrun utilising the output from the boiler and the original pump i.e. if either system causes the boiler to fire, the original pump will run on (or start up and run for a few mins if only the extension calls for heat). So, if the new boiler doesn't have a pump overrun output (shown as "From Boiler Pump Feed" on my drawing) then in it's place I could fit a timer relay (off delay of 5 mins or so?) with the relay activating when the RT signal to the boiler (or as shown on my drawing the "To Boiler Call To Heat" line) goes high - I think this would work. I have attached a copy of my existing setup wiring diagram. I have actually made a few mods to it today (not put these into practice yet) as I had a couple of issues with back feed to relay coils. Apologies for my scribbles!
    pump overrun.jpg
     
  5. Steelmasons

    Steelmasons

    Joined:
    10 Oct 2011
    Messages:
    16,405
    Thanks Received:
    3,969
    Country:
    United Kingdom
    Pretty simple really..
     
  6. Sponsored Links
  7. craig1234

    craig1234

    Joined:
    17 Nov 2008
    Messages:
    65
    Thanks Received:
    2
    Location:
    Kent
    Country:
    United Kingdom
    Time for an update.
    I contacted Vailant and they advised that the boiler does have a pump connection and should have pump overrun (documents attached). What I don't understand is why there is no mention whatsoever of the pump connection in the manual (on-line or received with the new boiler). Anyway, the boiler was installed and what a difference it made compared to the Ravenheat - chalk and cheese. The only issue I have is that I am getting a back feed from the controller meaning when the HW is live but the CH is off the extension heating comes on (i.e. I need to modify my overrun circuit in the above post) - not particularly a problem as I have both HW and CH timed to come on at the same time anyway and if the thermostat doesn't call for heat then nothing happens but it is not right so I will sort somehow.
    Thanks all for the advice.
     

    Attached Files:

  8. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    63,560
    Thanks Received:
    4,511
    Location:
    London
    Country:
    United Kingdom
    Well that's very interesting about the Vaillant.

    What's the Bunny response?

    Is it a last minute change based on experience ?

    Tony
     
  9. TCCHeating

    TCCHeating

    Joined:
    4 Mar 2013
    Messages:
    2,883
    Thanks Received:
    709
    Country:
    United Kingdom
    I've just read the documents and nothing has changed. It is still OK to wire the boiler with 3 wires and no pump overrun according to the second pdf

    All it says is that if the boiler has a perm live it must have pump overrun or it will throw up f codes. So no change to vaillants stance at all
     
    Last edited: 21 May 2016
  10. craig1234

    craig1234

    Joined:
    17 Nov 2008
    Messages:
    65
    Thanks Received:
    2
    Location:
    Kent
    Country:
    United Kingdom
    I think the documents are poorly worded and seem to contradict somewhat. What I think they are getting at is that yes you can run without pump overrun but there may be issues
     
  11. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Sponsored Links
Loading...

Share This Page