Thursday 13 November 2014

Combi Or Not?

What a great response from everyone yesterday! I couldn't believe what good replies I got to my questions. Thank you!

I had my thoughts about biomass confirmed and I think we'll be changing the boiler for another oil one, but situating it outside. Hopefully I'll be able to fit this with the help of a friend I've just done some work for, so plumbing costs should be minimal for the straight boiler swap, just the extra pipe work to take it outside (which I can do as well). 
I also need to concrete a little pad outside and install drainage under it for a downstairs loo before I do, so it will have to wait until it's dried up a bit first. In the mean time I'l do a little maintenance on the oil boiler to keep it running until then and use the wood burner as much as possible.
Ripping up floor boards in our last house to change the system to a combi.

 But that poses another question - to change to a Combi boiler or keep with the hot water tank system we've got? A combi heats the water as you need it for hot water, whereas the system we've currently got keeps stored hot water in a tank in the airing cupboard, indirectly heated by the water from the boiler.. I'm not sure I want to change the pipe work around to have the combi system as it means ripping up carpets and floor boards, although I'm sure a combi would be more efficient. We only use the hot water for washing our hands, baths for the children and washing up so having a tank might not be the best but if I start altering upstairs before Christmas it might cause a divorce! And it''s more work than I've currently got time for.
Thanks again for everyone's advice and experiences on the last post, I really enjoyed reading them and they all had some good advice in.

40 comments:

  1. I'd never have another combi - ours was oil and we were glad to see the back of it!. The only reason they're so popular is because plumbers like them - easier to install. IMO, the 'efficiency' claims are spurious.

    ReplyDelete
    Replies
    1. I cant see me ripping up the floor boards to change the whole system so I doubt we'll be going for a combi.

      Delete
  2. My husband is with Wanda on this. He keeps our boiler going and dreads the day he may not be able to do so.

    ReplyDelete
    Replies
    1. Thats why I like the idea of an outside one. I can work on it then and not worry about it killing us!

      Delete
  3. I really respect the knowledge of this man
    http://www.askjeff.co.uk/category/heating/
    Since moving to a bungalow in 2005 we are on our second combi boiler.
    They are brilliant when they work but have to be serviced every year for any guarantees to be valid and I believe are less efficient when they have to send water and heat over 2 floors.
    I hope you don't mind me saying but I do hope regardless of what you decide you have some carbon monoxide detectors fitted.
    We have a woodburner and it's wonderful but sometimes it is just nice to flip a switch and get warm without any effort especially if you are under the weather and can't wrangle wood.

    ReplyDelete
    Replies
    1. We have a carbon monoxide detector but more for the woodburner. I house is well vented by the boiler so I doubt there is much chance of that being a problem.
      Thanks for the link, I'll check that out later. I''ve got a plumbing book that I use a lot to figure things out.

      Delete
  4. Agree wholeheartedly with Wanda. We have had two combi boilers over the years, one mains gas and one oil, we did not find them efficient but we did find them to be problematic. Would never have another. There is a lot to be said for an old fashioned but well insulated tank, plus you get an airing cupboard in which to store all the bed linen.
    So pleased that you have decided against biomass.

    ReplyDelete
    Replies
    1. The airing cupboard also provides some heat to the house as well. the extension will have a small cupboard for towels and bedsheets as well as one cupboard doesn't ever seem enough!

      Delete
  5. We are looking into a thermal store heated by a back boiler and putting in underfloor heating. We can't find anyone who has done it but we think it will work. A thermal store seems to be one of the cheaper options to run but that's probably down to the fact we have a supply of firewood as we have a firewood business

    Still might be worth you looking into. Thermal stores need a lot of space though

    Miss Tulip x
    The Thrifty Magpies Nest

    ReplyDelete
    Replies
    1. oh I am very interested in this. I am now off to google all of this. we have underfloor heating in 2 rooms here. it is marvelous. We got it after visiting friends in Norway. Thermal stores... hmmm

      Delete
    2. I'm a bit mad in the fact I don;t like under floor heating (Brain commenting below thinks I crazy on this one) I don;t like a house to be too warm or if it is I like a way to get away from it. Building in thermal mass to a building is a good thing though. Our house now is masonry and once it heats up it really keeps it's heat well.

      Delete
    3. we have electric under floor heating as the rooms are all so small it frees up walls of the radiators which for the most part are ugly as sin anyways.

      Delete
  6. we have a combi. it saves us on bills and as our house is tiny we needed the space where the tank was so we could have a bath in our bathroom.

    ReplyDelete
    Replies
    1. The kitchen in our extension will be the furthest point away from the boiler so that's another point to put me off. If we were keeping the house this size then I think I would change.

      Delete
  7. You have some really useful skills, to be able to do all that. I can do minor repairs on plumbing, but usually I have to bring out a plumber. They charge me $100.00 for making the trip, then around $60.00 an hour. They can get away with this because there aren't many plumbers in this area.

    ReplyDelete
    Replies
    1. Well its not just me I have a couple of friends who I can trade skills with! There's not many plumbers around here and finding a good one is tricky.

      Delete
  8. Do you need to build a chimney? I think they require one here for oil burners.

    ReplyDelete
    Replies
    1. No a flue will do it. If the boiler is outside then it just need to be a set distance away from windows and doors.

      Delete
  9. I enjoyed reading your blog and the replies, yesterday Kev. If you look on my blog for Monday April 16 2012. You will see our solid fuel range. It's titled The Poor Smallholders Aga.

    ReplyDelete
    Replies
    1. I've got an Aga/rayburn (not sure on the make) that my parents took out that I could do up. The only trouble is it would never be very efficient and never was. It would save a lot of money though. Small firebox on yours.

      Delete
    2. Our Stanley Mourne number 7 runs seven radiators and we cook off it and have hot water. It cost us 2000 Euro about ten years ago. The firebox is fairly small. You could always do up your Aga and sell it to pay for your improvements. They make decent money Kev!

      Delete
    3. Ah, if I don't use it then my brother or sister would get first refusal before we could sell it! Only fair! I bet the price has gone up a bit since.

      Delete
  10. I am not sure a combi is what I was thinking. My previous point is that separating the domestic hot water and the house heat is best. They are two separate functions that have different requirements and can not be done as efficiently when combined. And combining them adds complexity and cost. A dedicated on-demand for domestic hot water only unit, and a separate boiler for house heat.

    ReplyDelete
    Replies
    1. Over here the boiler nearly always does both otherwise you have two boilers to maintain, I'm not sure I've been in many houses with two. Space is such an issue over here and not huge number of houses could loose the space for two.

      Delete
  11. we moved into a house with a combi. we hate it,its serviced every year and still never gets the water warm. Also not having a water tank makes me unhappy as there have been a couple of water problems with the pipes, with us not getting any water.we are looking to change as soon as poss.

    ReplyDelete
    Replies
    1. Having stored water in the tanks is another advantage, it might not last long but it;s better than nothing.

      Delete
  12. We had a installed and whilst I love the space the airing cupboard gives us I do find the water for the bath isn't as hot as I like it. Though the plus side we only use tax when we need hot water and not paying for gas to heat the hot water a good couple of hours before needed and there is unlimited supply. Also we have gone high tech and can mange our heating away from home and since our combi has been put in we have saved nearly 100 a month though our last boiler was 23 years old.

    ReplyDelete
    Replies
    1. 100 a month - Last year I don't think we spent £100 on oil all winter. We don;t spend much time away so not much need for high tec controls - if we are away then it's set just to keep everything from going damp.

      Delete
    2. All our radiators where very inefficient and I think the boiler was working overtime to try and heat both hot water and heating. That's all been rectified now and we hardley have the heating on at all. We only have gas as no where for a wood burner as council refused permission for a chimney.

      Delete
    3. We need to change our radiators as well as some are so old I can no longer bleed the air out of them! I remember you saying about your chimney, can you put a burner outside and just have it to cook on? Nice for cool summer evenings?

      Delete
  13. We've had many combi's installed over the years and learnt a few valuable lessons,
    1) get them serviced every year. This is a no brainer as you should get any internal boiler serviced every year CO poisoning isn't fun

    2)when serviced, make sure the central heating inhibitor is up to strength and the central heating water isn't full of crud. This crud will clog up the heat exchangers and cause problems

    3)the reliability of combi's has been improving. In the early noughties we were getting 5 years out of a boiler. It didn't help we were using a rubbish (in hindsight) brand -Ferroli. Now we are getting 10 plus years out of the gen 3 boilers, the current gen 4 boilers should be better. You can get an 8 year parts and labour warranty on the new ones.

    4)hard water is not good for combis.

    5) long runs from the boiler to tap are not great

    6) combi's are great for space saving, all your heating and hot water in a space the size of a kitchen cupboard

    7) the early combi's were very underpowered only 15, 20kw, hence the problems with not getting hot water. Newer ones are rated 25 to 40kw,menough to run 2 shower simultaneously. Frankly, if a new combi can't provide enough hot water for you, the problem is you're using too much hot water!

    8) linked to 7, try using 'eco' shower heads, they reduce the water consumption allowing the combi to achieve higher temps and saving energy!

    9)combi's are not great for linking to wood stoves, solar etc because they work best with a tank or thermal store, and if you have one of those, you don't need a combi.

    10)the move to condensing boilers (which all boilers have to be now) has made the reliability drop, more than the addition of the extra stuff to make a boiler a combi (essentially a heat exchanger and a flow switch). We still have some cast iron boilers kicking about from the late 80's! But the efficiency compared to the new ones is terrible!

    11) i'll mention getting your boiler serviced every year again. Being responsible for some 20+ boiler that have to be serviced annually (by law) it scares me how many people never get their boiler serviced.

    12) if you use a thermal store and a good sized system boiler, careful setting of the thermostat allows the boiler to replenish the store quick enough that the system essentially acts like a combi, providing infinite hot water for the odd occasion you need it

    13) If you have a good supply of wood it's daft not to have some way of heating water ideal both hot water and heating

    14)did i mention servicing?

    ReplyDelete
    Replies
    1. Good tips Brian - you should have a blog! Having so many boilers over such a long period of time gives you a good insight into what works. I don;t like paying a plumber £100 to hoover out a filter though and that's why I'm not a big fan of the whole servicing thing.

      Delete
  14. Cant say I'm with you on this one I'm afraid. Nothing worse than a stereotype and I follow blogs of many American woman who are none of what you describe above. You've obviously been hurt in the past and it sounds like you're describing the one woman that did it!
    Anyhow get back to the conversation in hand - what about American boilers - would you marry one of those?

    ReplyDelete
  15. Kev: I think you've been spammed. That is some robot spiting out crap emails so some poor sucker will visit the lame link he provides. Don't go there it is likely some virus.

    ReplyDelete
  16. I did click it and it's a blog against American woman, some of it is so bad it's funny!

    ReplyDelete
  17. Gosh, who'd have thought so many people would be interested in your new boiler! (I don't mean that in a funny way, it's nice that they are). We don't have a combi boiler either, it's nice to have hot water in the tank ready to go when you need it- even if the boiler breaks down it's still there for a while until you get it fixed. Our tank is in the airing cupboard in the bathroom, it has an insulation jacket on it and we also throw all the spare duvets and blankets over it and around it so it rarely loses much heat - probably not supposed to do that are we?

    ReplyDelete
    Replies
    1. Our's is covered in sheets and towels as well, should help it hold heat a bit better - although I doubt it's recommended! Also if the boiler breaks we can still have hot water buy using the immersion heater - that's a point I hadn't really thought about!

      Delete
    2. I have only just read your two posts about your boiler dilema. We have oil at our cottage in Scotland and the boiler is housed in a purpose built well insulated wood clad building attached to the outside of our house. It is more insulated than an ordinary garden shed so the boiler is well protected from frost - it also keeps quite warm all the time and makes a good drying room for coats and boots. We also keep some of our gardening tools and electricals in there to prevent them rusting. We have had no problems with it being outside.
      One thing I might mention in respect of the combi / or tank route is that many of the new taps on the market for both kitchens and bathrooms are made in Europe where they have mains pressure hot and cold water. Only combi boilers provide the right pressure needed to obtain a decent flow of hot water from most of the modern mixer taps on the market. We know this because our house here in Yorkshire has a gas boiler and an old tank fed system. We recently had a new bathroom and taps and the hot water is just dribbling out of the hot tap whilst fine on the cold which is straight off the mains. We are now having to install a pump to boost the pressure. Although you can still get taps that are suitable for lower pressure most manufacturers seem to think that everyone has a combi boiler these days. Just thought I would mention this so you can have a look on the internet if this might be an issue for you in the future.

      Delete
    3. That's interesting and I was talking to a friend the other day about something similar (Brian commenting above) that's why a thermal store can work quite well as the hot water comes in at mains pressure. Also when I did mum and dads bathroom we had to install a water pump to get the shower to have enough pressure.
      I like the idea of a shed around the boiler! Not sure where I'd put it though - but somewhere to put things that we could keep the frost off would be really handy.

      Delete
  18. This spammer is dropping this crap in a lot of our gardening blogs over here. What a jerk. We have to keep deleting him.

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...