Combi Boiler?

Discussion in 'Home energy' started by JohnJay, Jan 9, 2017.

  1. JohnJay

    JohnJay Frequent Poster

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    I need a new boiler. I also need to move my hotpress and replace my hot water cylinder. A plumber has recommended a combi boiler. What are the thoughts on them?

    Its a medium sized house. 1 occupant usually, 1 bathroom. A combi probably makes sense when I think of it.
     
  2. aprentice

    aprentice Registered User

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    There alot more popular in the uk than they are here
    Personally i think theyre great when my boiler goes ill be getting one and scrapping the hotpress
     
  3. JohnJay

    JohnJay Frequent Poster

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    yeah, I know my brother had one in the UK 10/15 years ago. It was mains-fed at the time so the pressure wasn't the best. Apparently the new ones are fed from an attic tank and are pumped for extra pressure
     
  4. Firefly

    Firefly Frequent Poster

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    Last edited: Jan 10, 2017
    Hi, we are looking at this also. If anyone has experience with one of these I too would be very interested..
     
    Last edited: Jan 10, 2017
  5. NewEdition

    NewEdition Frequent Poster

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    Why exactly is this? Its a no-brainer in my opinion.
    On demand hot water, no heating a full tank of water unnecessarily or even heating a tank of water when you dont even need it because the heating is on... and also, the dreaded immersion!!!!
     
  6. odyssey06

    odyssey06 Frequent Poster

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    Speaking as someone still stuck in immersion land and concerned about leaving it on and triggering a thermonuclear explosion that will take out half the area...

    Is there any drawback? Is it more expensive to buy \ install?
     
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  7. Firefly

    Firefly Frequent Poster

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    They seem to rock. I'm working with a few guys from the UK at the moment and they're all saying they can't believe we don't have them here. 2 sources from the boiler - one for the heating and the other for the taps. When you turn on the hot tap, the boiler kicks in and heats the water as it passes through the boiler. Thinking of feeding the main shower from this with a pump if necessary for a nice power shower. We will have a shower in our downstairs bathroom also but will install an electric shower there in case the boiler is ever out of action..
     
  8. demoivre

    demoivre Frequent Poster

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    Some folks like a hot press to air clothes. Not sure either that a combi is suitable for houses where you might have a few showers going at the same time and that need a hot water feed. The immersion should only kick in when it needs to bring the water temperature back up to what ever it's set at. If you aren't using the hot water the immersion left on shouldn't be using much electricity. IMHO of course. ;)
     
  9. Leo

    Leo Moderator

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    The main reasons they're not as popular here is that incoming water pressure generally isn't up to the job and there are also issues with limescale.

    Before Irish Water was created, Dublin bylaws prohibited the fitting of combi-boilers to the mains, and the fitting of header tanks with a pumped feed from that tank was a means of getting around the regs and achieving the required input pressure to the boiler. I'm not sure if that has changed.

    The higher lime concentration in many water supplies will mean the heat exchanger will clog, affecting efficiency and limiting the lifespan of the exchanger potentially to a matter of months. Using softened water will invalidate the warranty of any boiler with an aluminium heat exchanger due to corrosion issues.
     
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  10. Thirsty

    Thirsty Frequent Poster

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    I have a combi boiler in a high limescale area. Yes have to descale, part of normal maintenance/service so no big deal.

    Still have 'hot press' but half previous size and fully shelved out. Tiny radiator at the back of the cupboard provides heat for 'airing' household linen /clothes.
     
  11. lukegriffen

    lukegriffen Frequent Poster

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    I got a combi boiler in recently & the water flow upstairs wasnt good enough to kickstart the boiler, so i ended up having to pay more for a pump. Im still glad i got it, great to get rid of a cylinder in hot press, house heats up quicker & bills cheaper. I kept the electric shower. Im in kimmage dub 12
     
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  12. roker

    roker Frequent Poster

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    Can this be done with oil?
     
  13. hfp

    hfp Frequent Poster

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    Combi boilers might have changed since I got mine 12 years ago, but when mine was installed they couldn't be combined with an additional pump as it's already a pressurised system. The installer did a pressure test on the taps to ensure that it was sufficient for a combi boiler to be installed.

    I wouldn't be without the combi boiler, no waiting for water to heat up, no running out of hot water mid shower/bath, no oil tank and no immersion heater. Pressure wise it's definitely not as good as a pumped power shower, but miles better than a standard electric shower and I just have an adjustable shower head for a stronger jet when required. The pressure does drop the higher you turn the temperature, so if you like your shower scalding it might not be ideal!!
     
  14. Firefly

    Firefly Frequent Poster

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    Hi,

    Yes - I checked with my plumber and the pressure is decent. Will report back with hopefully good news!
     
  15. Firefly

    Firefly Frequent Poster

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    Just an update on this. We have had our Combi installed and running now for about 6 weeks. It's fantastic. Once the taps are turned on in the bathrooms and kitchen the boiler kicks in and shortly later we have hot water. Ditto for the shower - although we don't have enough pressure for a power shower without spending a grand or so on a AquaBox and pump, we are getting perfectly adequate hot water. It's nice too to have a shower without the sound of an electric shower. Finally, the rads are piping hot and since we replaced a lot of our rads with vertical ones with higher water volumes they are still warm an hour after the heating is knocked off. We now have no water cylinder and hot water on demand. Haven't received our bill yet though!