Sorry guys, I know this is boring. We are going to replace our back-boiler with either a Combi or Condensing boiler. Any suggestions about which would be best would be appreciated:thumb:
I have only had a quick look as we are about to go offline. My impression is that you either have a conventional boiler (with a hot water tank) or you have a combi boiler (with no hot water tank - it just heats it when you want it like the old Ascot heater). Combi boilers seem to be popular now as maintaining a tank of hot water at all times is wasteful. But there are some disadvantages, such as the flow of hot water is reduced (baths take longer to fill) and your system is run at a higher pressure, ie the cold main water pressure. Will your pipework and joints take this. I think both of these boilers can be supplied as ordinary or with an added condenser. The added condenser will add cost but will also increase efficiency. But have a look at this site http://www.condensingboiler.org.uk/ It suggests that if your system doesn't run under exactly the right circumstances you may not get the added efficiency that is advertised. One final point. I have a friend who was a power station engineer. He commented one day that he would never touch a condensing boiler. because by its very nature it condenses water at one point which is very acid. He said this corrodes the boiler and they don't last long. He is elderly and may be out of touch with modern boilers - but it is worth asking about.
I have a combi and find it great, highly recommend one. Try to avoid Baxi though as their reliability is a bit suspect apparently
You don't have any choice about whether to go for a condensing boiler or not, you have to fit condensing boilers now (they are supposed to be more energy effecient) and thats the only sort you can buy. My In-laws had one as a replacement last year, and it was a pain getting rid of the condensate (the acid stuff PeterS mentions), there needs to be a nearby drain for it to be plumbed into. Whether you go for Combi or conventional depends whether you want to get rid of the hot & cold water tanks. Also Combis heat hot water on demand so that might be a problem if all your family shower/bath at the same time.
"they are supposed to be more energy effecient" Nerdy mode = ON You do need to run condensing boilers with the return water below a certain temperature to get them to condense, and thus get the extra efficiency; so I think it may be worth considering how best to achieve that. Having a system that just cycles on and off once the whole central heating circuit has heated up is probably not going to give you the saving you'll see advertised!! whereas if you have some sort of tank [usually referred to as a Thermal Store] that can also be heated (i.e. keeping the boiler in condensing mode for longer periods) and that then provides the hot water (i.e. to the central heating circuit) for an extended period, will make the boiler perform better / more cost effectively. The second route is also likely to be more compatible with solar water heating, if you are up for that. But adds to the initial cost, of course ...
kristen I agree with you about the so called efficiency. And also with PeterS about the life of these condensor boilers. The old fashioned ones have long lasting cast iron gubbins whereas the new condensor jobbies are made of thin copper sheets and small bore pipes - which will wear out/block up much quicker. I'm hanging on to my old 'non-efficient' boiler for as long as I can, its already over 20 years old and I'm sure will last a few more. It may cost a few pounds a year extra to run compared to a condensor but the life of these modern ones is likely to be 10 years or less (and cost £1,500 to £2k to replace!) All in my own opinion of course!
We're replacing the heating system next year and have been looking at which boiler to get. Decided as there was only 2 of us to get a condensing boiler as we don't use that much hot water. I think the combi option was more expensive too.
I'm switching from Oil to Wood central heating boiler in a few weeks. That will save me half my fuel costs (at current prices, and assuming I buy all my wood). And that's without the addition of Solar Panels (next year's project) which should save a fair bit more. Slightly scary capital cost though, but it aint all about "money savings", I'm keen to do some plant-saving too ...
Thanks for all the replies. The Combi boiler seems to be the simpler of the two. I think we'll go for that
Cajary - you need to do some Googling and some talking to people who aren't going to profit by selling to you. I had a further Google, after the system went down for a couple of days, and found one page that suggested that a new law has been bought in making it compulsory to install condensing boilers irrespective of whether you wanted one or not. I also found another site with some terrible stories of their unreliability. The best person to speak to is a boiler maintenance engineer - ask him which ones he never has to repair. As for me, my boiler is now 45 years old, and hasn't been serviced from the day I moved into the house 26 years ago. As my heatring bill is well below the national average, I am not in a rush to replace it. But then - what do I know about economy - I am only a consumer not someone clever like a politician.
Thanks PeterS. I spoke to my son-in-law and it seems that all boilers have to be combi/condensing types. I might just smile sweetly at the MBH and suggest we keep our back-boiler until it breaks/down
Caj, your son-in-law is not quite right: all new boilers must now be of the condensing type by law, but its up to you whether you want a combi or not. If you don't have to replace I would keep what you've got.
