Combi boiler question

Bogof_Babe

We currently have a back boiler but it's becoming a bit unreliable so we're seriously considering a replacement, and as combi boilers seem to be the way to go these days we're probably going to go for one of those.

However I would really miss my airing cupboard where the hot water tank is, so I'm wondering whether there is such thing as a combi boiler that also feeds a hot water storage tank?

The last person who came from British Gas to fix a breakdown said he didn't think you could get such a thing, and suggested keeping the airing cupboard as a space, and having a small central heating radiator in there, but that would mean having the heating on in summer when I just want to dry some laundry.

The other thing is that if ever the water is cut off for any reason (external pipe work or something) at least we would have what's in the tank to tide us over.

Alternatively, can anyone recommend a replacement back boiler suitable for a 3-bed detached house, or are these obsolete now?

Owain_Moneysaver

You can have a hot water cylinder off a combi boiler; the HWC is just plumbed and controlled as another radiator zone using an S Plan Plus control system.

Or you could have a radiator in the cupboard on a separate radiator zone.

However if you want to dry washing it will probably be better to install a small dehumidifier in the cupboard.

ormus

british gas numpties.

http://www.plumbingpages.com/featurepages/HWunventedhome.cfm

of course you can add a hot water storage tank, to a combi/system boiler.
add another 1k (approx) to the cost of your boiler.
ps
all these systems work on mains pressure. so if the mains fails then so does all your H/C water.

afaik
non of these systems use a CWS tank in the loft.

Bogof_Babe

Thanks both. Interesting and helpful replies. Don't mind the extra cost to get what we want. Will look further into it.

keystone

If you want to retain your Hot Water Storage then forget about a combi boiler. Go instead for a system boiler which would replace your existing boiler.

Using a system boiler you can either keep your existing open vented (cold water storage tank in roof + existing Hot Water Cylinder) system or replace the CWST and the HWC with an unvented cylinder.

Using a combi for what you want to achieve would be barmy.

Cheers

jennifernil

Surely the whole point of a combi boiler is to do away with the need for a cold tank in the loft and a HW cylinder?

Combis were originally developed to save space in flats and smaller houses, if you have the space and want to keep the airing cupboard then you install what I would call a "normal" boiler. (presumably that is the same as a system boiler)

Personally, I prefer the normal system, I like to have the stored water and the ability to heat the HW with the immersion heater should there be a problem with the gas boiler. I like having an airing cupboard too.

I also think there is probably less to go wrong with a normal boiler.

closed

heat only/regular or system boiler, both condensing

http://www.worcester-bosch.co.uk/homeowner/boilers/gas-boilers

Bogof_Babe

That's a great link closed, will help us decide.

I thought "system" (presumably the same as "back"?) boilers were considered old fashioned these days. Ours is behind the gas fire in the living room, and is a bit of a palaver for the engineer to access, which is probably why *he's (*all of them really) tried to steer us towards a combi.

Hmm, more thought needed.

Ebe_Scrooge

A back boiler may well be considered old hat these days, but you could easily replace it with a "normal" boiler sited somewhere more convenient ( often in a kitchen or utility room ). This would still give you the hot water tank, and a modern condensing boiler ( not to be confused with Combi ! ) will be much more efficient than your old one.

As has been stated previously, the big advantages of Combi boilers are that they remove the need for storage tanks, and you only heat the water as and when you need it, so although you CAN add a storage tank to a combi system it somewhat defeats the object.

There are pro's and con's to combi boilers - they're slightly more expensive to buy and they're a bit more complicated, so more parts to go wrong. They also sometimes struggle to provide a decent flow rate, especially if the incoming water is very cold and you're trying to run a bath and operate a shower at the same time. Having said that, modern combi's are a world apart from the old systems we had < cough cough ahem > years ago in my student flat :-)

On the flip side, they can provide quite a saving in fuel usage, since you only heat the water you need, you don't heat a whole tankful only for it to go cold if it's not needed. Plus you don't run out of hot water if several people have a bath one after another. Although if there's a problem with the boiler, you don't have the backup of a tankful of hot water to see you through.

Horses for courses, really, depends on your particular circumstances as to which will be best for you.

eeeeeee

water storage tanks arent so funny when they burst and cause extensive damage ...its nothing too do with your supply pipe water being too cold your water supply will always be at ground temperature,,, if it was too cold it would be frozen ; you need too ring your water company and ask them for a pressure test BEFORE you have a combi on condensing boiler fitted .. too ensure that adequate pressure is at the 1st incomming tap ; if the water pressure is low at the point of installation ( ie the utility room not at the 1st incomming tap) then you will need too have the rest of your plumbing checked ... poor pressure is the biggest cause of cold water from a combi boiler ... followed by a common supply pipe ... then an overwhelming useage ( ie fire brigade useing the hydrant )

macman

If you would like to retain your hot water tank and airing cupboard, and don't have a need for hot water on demand 24/7, then why not just fit a conventional condensing boiler? I can't quite see the point of a combi in conjunction with a tank?