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Discuss Baxi 105 HE cool radiators in the Central Heating Forum area at

  1. Wingnut

    Wingnut New Member

    Hello all
    1st post so be gentle
    when i moved into the property we had 5 single and 1 double radiators all providing loads of heat
    1 - Kitchen
    1 - Living Room
    1 - Hall
    1 - Bathroom
    1 - Bed 1
    1 - Bed 2
    1 - Study
    1 - Double Dining Room
    Since then ive exchanged some of the singles for doubles
    1 - Living Room
    1 - Bed 1
    1 - Bed 2
    The rest are as original
    when installing the last rad (Bed 2) and recharging system ive noticed that the radiators arent as hot as they were, also the return pipe is cool (all lockshields and TRV are fully open)
    Ive replaced the Grudfos pump for a 3 speed one and set it on speed 3 and put sentinel x800 through the system.
    ive also noticed that when you open the kitchen tap 1/4 turn steam comes off the water flow but if you fully open the tap it is noticeably cooler (the DHW Diaphragm has been changed two days ago)
    ive ordered a CH diaphragm just in case its that and also a new PCB, its also worth noting that the boiler temp very quickly achieves 80 then pilot light extinguishes (no fault LED) and doesn't reignite until 30/40 is reached, any ideas?
    Last edited: Dec 3, 2018
  2. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Yes please stop guessing at fault finding on your boiler and get a proper gas safe engineer in
    • Agree Agree x 2
  3. Wingnut

    Wingnut New Member

    Can you at least give me some pointers?
  4. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Pointers about what mate? Working illegally on your boiler?
    Last edited: Dec 3, 2018
  5. Wingnut

    Wingnut New Member

    Ok point taken
  6. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    I don’t think you’ll find part of the problem is the boiler is your system water dirty?
    • Like Like x 1
  7. Last Plumber

    Last Plumber Trusted Plumber GSR

    If you have changed single rads for doubles that does not mean you will automatically get more heat out. Pipe size counts for a lot. I am not saying that's the answer but it could well be an influence.

    The Water temp coming into your property will have an effect on the temperature of the hot water out of a Combination Boiler. There will or could also be differences due to flow rate.

    My advice to you is to get a Heating Engineer to deal with your issues. It does sound like you have more than one or two but they may not necessarily be as a result of faulty components.

    Throwing parts at something and using guess work will only cost money. It could work out a lot cheaper to pay an experienced Heating Engineer for a couple of hours to sort things out.
    • Like Like x 1
  8. Wingnut

    Wingnut New Member

    It was when I first flushed it but after x800 it was clearer, could it be a balancing issue?
  9. SimonG

    SimonG Trusted Plumber

    Nowt wrong with boiler.

    Spent a lot of money on a simple fix.
    • Like Like x 2
  10. Pickwickpick

    Pickwickpick Plumber

    If all of your lockshields are fully open that won't be helping matters.
  11. Wingnut

    Wingnut New Member

    I’m thinking I’ll need to balance the system, is there a guide anywhere?
  12. Chuck

    Chuck Well-Known Member

    Pinned post at the top of this forum:

    Croppie's Balancing Thread.
    • Like Like x 1
  13. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    You’ll probably need to balance it but that’s not your problem
    • Like Like x 1
  14. Wingnut

    Wingnut New Member

  15. Wingnut

    Wingnut New Member

    what could be the problem then?
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