I've had several plumbers round and they are all scratching their heads as to where I can locate a standard flued combi boiler. On of them found the Keston C36 on the internet that uses 2 x 50mm plastic pipe for the flueing. This looks just the job. Can't find much in the way of reviews on these apart from a very disgruntled one on the screwfix site. I'd be very grateful if anyone can give me feedback on these boilers before I take the plunge, cos they aint cheap?
Good, they've found a suitable location for the terminal. But 2 x 50 mm is still about the diameter of a 100mm concentric flue. Not going to comment about the Keston but I'd think harder about routing options for a standard flue.
Thanks Jim. The only place I can realistically flue it out via a wall in is in the corner of the kitchen through a 69cm stone wall. On the outside though, there's a very small space between wall and next door neigbours. Plus there are original (house built around 1870) iron waste pipes to negotiate. Hopefully, the 50mm pipes should squeeze through, plus the outlet pipe from the Keston could be routed up to the roof somewhere. Which, as I understand it, you can't do thei with a 100mm flue. The existing boiler vents up a chimney, but none of the plumbers could suggest a condensing combi boiler that could do that. We do have a utility room that could house any boiler on the other side, but that would mean long runs of pipework between the boiler and kitchen/bathroom.
If there's any length involved, then the Keston will probably be a lot cheaper to install. More than one boiler manufacturer charges serious money for flue extensions. Note to the OP: you need the muPVC high temp waste pipe not the regular stuff. It's a bit more expensive but not hugely so.
Of course I respect householders looking for help, it's just plumbers opinion I dismiss.
If you *want* a combi fair enough and long pipe runs are not good for combi DHW but what about a storage solution with a system boiler in the utility room?
It not only the size but also the ability to have a very large number of bends (each equivalent to 0.5m of plain pipe) and still comply with the manufacturers. The ability to have so many bends allows the pipe to go around obstacles which would be prohibitive to do with 100/60 concentric pipe systems.
There have been a number of posts about Keston over the last 6 or so years. Most will relate to the Keston C25, but probably apply to the C36 too, so search back with Google.
Having installed one, I would consider installing another, but I have a reservation too.
I like the technology, and it's well built. There have been some problems with the boilers, but Keston do seem to have a programme of continuous improvement to address those. Examples are the internal flue pipe on the C25 which is now on it's 3rd version (earlier ones tended to split causing boiler to lockout) and the ignition electrode which has a tendancy to droop (more so in the C36 are larger boilers acoording to reports on the internet, but I've had it happen in my C25 too). Contrast this with Potterton who have knowingly continued supplying Suprimas for years with a badly manufactured circuit board which often requires an expensive replacement just out of warantee.
However, the lack of availability of spares is something that I would take very seriously. When I needed a new ignition electrode, I had to wait over 2 months for one in the middle of winter. HRPC couldn't get any from Keston, and said they had to wait for a batch to be made. HRPC don't stock them. That is completely unacceptable for a central heating boiler. If that had been my elderly parents' boiler, we would have had to chuck the Keston and fit another boiler. As someone else commented at the time, every HRPC (Keston's chosen parts supplier) should have a stock of such parts on the shelf. Fortunately, I managed to bodge the broken electrode to continue working in this case.
So I now keep a few spares at home. Whilst I would probably still install another Keston C25 for myself as I have got to know it very well and I like the technology, I would regard the boiler as unsuitable for my parents for example, due to the lack of immediately available parts. This unacceptable parts situation seems to have been going on for some time according to others reports here. It's worrying that Keston don't seem to have addressed it (or possibly even recognised it).
Keston was bought by Ideal Stelrad in August last year.
Thanks for the masterclass but my post was never about tying knots in concentric flue. I suspected that the OPs first post didn't tell the whole story about boiler siteing options, something which was later confirmed. If the OP wants to restrict his boiler choice to one for the privelage of having a combi, well that's choice.
Thanks for all the replies. As Jim says, the other option is to fit any system boiler in the utility and a mains pressure hot tank in the loft (assuming the joists would take the load and there is enough space!). But this would involve new and awkard very long runs of pipework between boiler and hot tank. Probably work out a lot more expensive and do a fair amount of damage! Any comments on the long runs of pipework to the water tank?
Also been looking on diynot forum, quite a few posts on Kestons. Not a great amount of positive comments, but this all seems to be directed to the Celsius 25. In one post,
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corgi installer says that the C36 is not just a combi version of the C25. The internal components are different and he has fitted a few with no higher incidence of problems than any other boiler.
The long run in itself needn't be problem. Probably a couple of 22mm. Necessary insulation makes it bigger of course. Can't comment on the practicalities in your case but given the choice of a difficult uPVC route carrying flue gas and a difficult copper/polybutelene/pex route carrying water, for me its a no-brainer. The hot cylinder doesn't need to go in the loft unless that is your only space. Don't mean this to be an vented/unvented/heat store/heat bank argument but there are choices you can make. While a storage solution is likely to be more expensive than a Keston combi solution, a properly designed storage solution will offer much improved DHW delivery with a bonus of immersion backup.
Thanks for all the replies. As Jim says, the other option is to fit any system boiler in the utility and a mains pressure hot tank in the loft (assuming the joists would take the load and there is enough space!). But this would involve new and awkard very long runs of pipework between boiler and hot tank. Probably work out a lot more expensive and do a fair amount of damage! Any comments on the long runs of pipework to the water tank?
Also been looking on diynot forum, quite a few posts on Kestons. Not a great amount of positive comments, but this all seems to be directed to the Celsius 25. In one post,
formatting link
corgi installer says that the C36 is not just a combi version of the C25. The internal components are different and he has fitted a few with no higher incidence of problems than any other boiler.
snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote in news:46097d3b$0$757$ snipped-for-privacy@news.aaisp.net.uk:
Thanks for the heads up on the spares front.
As part of the renovation project which is our current house, I selected the Keston C36. The flueing was one criterion, the other was the high DHW flow rate.
I ordered the boiler on-line from discountedheating.co.uk [but it was actually supplied from a Wolseley's PlumbCenter branch]. I asked my local independent plumber's merchant for a price - they were reasoanably competitive but a little more expensive. I would have preferred to buy from them, but then they added a £20 'palleting charge' so they lost the business. I don't have the price to hand, but I'm sure I paid a lot less than the high price I see now.
It's still early days (commissioned 7 months ago) and I'm satisfied with it thus far. I can recommend the external weather compensation option and the (somewhat expensive) programmer [Aside: this is actually a badged Theben Ramses].
The Keston C36 is the first combi I've had, and its performance - as gauged by DHW - is good. It can fill a bath at a 'proper' rate and run a ferocious drencher shower.
It's too early to comment on reliability. I have made one service call to Keston (I thought it best since it's under warranty) when the DHW temp became unstable causing the boiler to overheat and cut out. This turned out to be caused by debris on an internal filter and so a simple fix. This call was fielded by an independent small plumbing firm (two men in a van) who cover a wide area and specialise in Keston products. The response time was good, but perhaps indicates that resources from the manufacturer are limited.
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