Megaflo only heating with Immersion?

Discussion in 'Plumbers' Talk' started by MarkLucas, Aug 13, 2019.

  1. MarkLucas

    MarkLucas New Member

    Hey everyone,
    We bought this house and don't know much about plumbing, and we haven't received any information from the previous owners as to how the central heating was set up.
    It's a 4000 sqft house, which is heated with a combination of underfloor heating in the ground floor, and radiators on the top floor.
    We have a Vaillant Ecotec Plus 637 boiler and a Megaflo Indirect of 300L capacity.
    We had smart meters fitted this week and I noticed that the electricity usage has some spikes of 3000W for about 5 minutes, and it keeps doing it all day long. Upon investigation, I found out that's the Megaflo.
    Since I have an Indirect Megaflo, I presume it must be connected to the boiler as well. However, since the boiler is not being used since the heating is off for the house, I imagine the Megaflo must be heating only with electricity.
    My question is: If the heating is on, can I presume that the Megaflo will be getting some of the heat from the boiler?
    There are 3 switches next to the Megaflo which I couldn't exactly find out what they did. One of them seems to turn off the Megaflo as a whole, another one is connected to a timer, which is then connected to a DAB Pump connected to the Megaflo, and the last one I have no idea because it goes inside the wall.
    I tested turning on the hot water using my thermostat and nothing seems to happen. The boiler doesn't have the icon for hot water, only for heating.
    I attached some pictures, that I hope will help to understand.
    Any information I can have would be greatly appreciated.
    Thank you from a very concerned new homeowner :)
    20190813_135537.jpg 20190813_135551.jpg 20190813_135614.jpg 20190813_135637.jpg
     
  2. Martyn21uk

    Martyn21uk New Member

    I have a very similar set up in my house and this is how it works for me...

    Ecotec boiler supplies central heating heat, hot water to the kitchen tap and hot water to the Megaflow tank. We have an electronic timer next to the Megaflow tank that controls the times it will call for hot water from the Ecotec boiler. The immersion is never switched on and is only there for back up in case of failure of the boiler. The Megaflow tank then supplies hot water to both bathrooms (2 showers, 1 bath, 2 sinks).

    Hope that helps...
     
  3. Mike83

    Mike83 Well-Known Member

    The megaflow is piped up to be heated by the boiler.

    To be honest there’s a fair bit happening with that set up.
    Maybe best to get it all serviced (boiler and cylinder) and then ask the engineer how it works.
    The pump for your heating/hw is built into the boiler.
    The other pump could be a secondary return for the hot water.
    There also seems to be 3 zone valves on the system.
     
  4. MarkLucas

    MarkLucas New Member

    Indeed, I've had some plumbers look at it and just say "yea mate, this is too complicated for me".
    How can I find someone who I'm sure will understand how it works?
     
  5. Mike83

    Mike83 Well-Known Member

    It’s not that complicated but easier to explain in person than on a forum.

    We’ll try though.
     
    Heat and The Teach like this.
  6. The Teach

    The Teach Well-Known Member

    what you need is a heating technician to visit you it will take a few minutes to understand your bespoke system (few minutes=scratching ball ocks or similar)

    once the tech understands how it all works,they can instruct/walk through the end user.please take notes during the instruct walk through.

    So easy :D
     
  7. Mike83

    Mike83 Well-Known Member

    The red circled switch is the immersion.
    The blue is the pump for the secondary return which goes via the timer 1643F011-4D9D-47A7-A705-40F6CD91F547.jpeg
     
  8. The Teach

    The Teach Well-Known Member

    Ok good question. how much cash you willing to spill ;)
     
  9. Mike83

    Mike83 Well-Known Member

  10. Mike83

    Mike83 Well-Known Member

    Buttons in red control the hot water.
    Buttons in blue will control 1 of the heating zones.
     
  11. MarkLucas

    MarkLucas New Member

    Thank you so much, that really helped.
    Why does that pump you circled blue need a timer, shouldn't it be on all the time?
    Regarding the buttons in red for the hot water, when I turn that to continuous I hear some clicking sounds, but the boiler doesn't turn on and nothing seems to happen. Maybe the fault is here?
     
  12. MarkLucas

    MarkLucas New Member

    The obvious answer is the least possible, since right now the hot water is working, although with a higher cost than should be necessary..
    Maybe I should have someone do an annual service and get this fixed as well?

    Thanks
     
  13. Mike83

    Mike83 Well-Known Member

    DFE10D69-4CB4-4F84-9798-D15520642AA5.jpeg The clicking noise could be the HW zone valve opening. If so this should then fire the boiler.

    The additional pump that you have with the timer is there to try and give you fairly instant hot water when an outlet is opened. The plumbing will have been done different to normal to accommodate this.
    It’s seen but not that common in a domestic scenario.
     
  14. MarkLucas

    MarkLucas New Member

    That makes sense, thank you so much for your help.

    Last question - when it's all working, I presume the megaflo will always use both the immersion and the boiler, or will I be able to completely turn off the immersion heating?
     
  15. Mike83

    Mike83 Well-Known Member

    The immersion is backup only.
    Should only be used when it’s not working via the boiler.
     
  16. MarkLucas

    MarkLucas New Member

    A heating engineer was here and diagnosed that indeed that valve is faulty.
    He quoted me £200 to supply and fit it.
    Does that sound about right?
    Thank you very much
     
  17. Mike83

    Mike83 Well-Known Member

    If it’s for his time today and fitting the valve then yes.
    You can also get him to show you how it works.
     

Share This Page