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

How often should an electric immersion heater turn on/off?

Discussion in 'Plumbing and Central Heating' started by stoduk, 9 Jun 2018.

  1. stoduk

    stoduk

    Joined:
    9 Jun 2018
    Messages:
    2
    Thanks Received:
    0
    Country:
    United Kingdom
    I've got a vented hot water cylinder with two immersion heaters (economy 7 and boost). I've noticed recently that when heating overnight I can hear the element turning on for only 10 seconds or so before turning off again, repeating this cycle soon after. Last night I noticed it around 5am, so it will have been heating for quite some time - TBH I'm surprised in summer that it still needs to turn on by then.

    Can anyone comment on whether this behaviour is expected or not? Perhaps I'm just noticing what it has been doing for years!

    It is a standard element with a built-in thermostat so I would expect it to get to temperature and turn off for quite a while (I'm assuming these are bi-metallic strips so they don't react that quickly AFAIK). I've just checked and the temperature setting was near the top of the (10-70 ÂșC) range, so I've turned that down.

    TIA!
     
  2. Sponsored Links
  3. flameport

    flameport

    Joined:
    10 Mar 2007
    Messages:
    8,949
    Thanks Received:
    1,708
    Location:
    Poole, Dorset
    Country:
    United Kingdom
    That's what should happen.
    Turning on/off every few seconds probably means it's completely clogged with scale, and isn't actually heating the water.
     
  4. stoduk

    stoduk

    Joined:
    9 Jun 2018
    Messages:
    2
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks for your response. Scale could well be a problem, the water is incredibly hard around here. I doubt having the thermostat set so high was useful as that will have accelerated scale deposits. The water is still heating up overnight, but maybe it is less efficient at transferring heat if there is an insulating layer of scale - which could explain the faster cycling.

    I'll see how turning the temperature down affects things, but perhaps it is time to invest in a water softener!
     
  5. 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

     
Loading...

Share This Page