Alternatives to Keston boilers - need narrow flue

[simonc1]

I'm looking to have a boiler installed that has a narrow flue - perhaps 50mm, due to its location within a listed building. The keston is attractive as it offers a narrow flue, but there are lots of questions about reliability.
Is the keston range as bad as people make out? If it is, can anyone recommend a manufacturer who offers a narrow flue option?

Thanks.

[45yearsagasman]

Baxi have boilers that use either a concentric flue or can be adapted for twin flue use which is what your Keston uses.Not sure of exact models but we have a few Baxi guys on here who will be able to advise.

[SimonH2]

45yearsagasman wrote:

Baxi have boilers that use either a concentric flue or can be adapted for twin flue use which is what your Keston uses.Not sure of exact models but we have a few Baxi guys on here who will be able to advise.

I was about to ask much the same question - are Keston as bad as people make out ? I've been puzzling how to do the flue when I have to change the boiler as the garage doesn't have an outside wall. I've had a couple of people to look and they want to go through the bin store and come out on the steps (thigh height coming down, face height going up), and then run a plume diversion kit half way across the wall to get the flue away from people. Now I don't like lots of external pipework, and I really don't want loads of flue all over the back wall.

The garage door is set in from the back wall of the property to form a carport sort of space with the bin store off it. The current (old) boiler flue dischrages into this space and it's not really acceptable as it creates wetness that has already made the boarding fall off. It wouldn't meet regs anyway for a new install.

To run a flue out from here would mean going over the steel RSJs that support the back wall - and there's only about 2" gap before I'd have to cut into the blocks of the floor above. When the guy at the plumbers merchant told me about the Keston boilers with the 50mm plastic pipe I thought this could be just the ticket. I am rather concerned about their poor reputation though.

I've just had a read of the manual for the Baxi Solo HE range. I reckon I could probably manage the 70mm plume diversion flue pipe, BUT I'd have to take the flue extension either (depending which way I routed the concentric flue) :
- straight off the end of the concentric flue (ie just extend the central tube in-line) or
- fit the plume diversion kit with the outlet horizontal (the manual specifies it to be vertical).

I don't think the Baxi twin flue setup would work for me - firstly the pipes are a bit big, and all the diagrams show them being recombined to a concentric terminal.

[mickyg]

if you can manage 80mm, you could use a twin flue adaptor off most boilers(glowworm, atag etc...). and yes kestons really are that bad.
Remember all joints of any flue will need to be accessible for inspection

[transam]

The only other boiler that I know off that used a keston type set up be it in ally not plastic was the Quantum ?? but I think ?? that they ceased production not to long ago ????????? cannot remember who they were something ? engineering up north ? stainless steel engineering firm make parts for BA ?? (maybe)

[picasso]

Atmos do a boiler compatable with a 50mm mupvc twin flue

http://www.atmos.uk.com/

[pampers]

Keston are worse than you have heard truly a stack of steaming (well usally not steaming when i see em as they broken) poop.

[SimonH2]

picasso wrote:

Atmos do a boiler compatable with a 50mm mupvc twin flue http://www.atmos.uk.com/

I've also seen suggestions for Wiessman.

Both Atmos and Wiessman are brands I'm not familiar with - what are people's thoughts on them - are they good/bad/indifferent for reliability cheap/expensive/so-so on price ? I'm guessing they aren't all that common, does that mean I'm likely to struggle finding someone local who can service them ? I'll be asking the people who currently service the system for their thoughts - but I'm always wary that people tend to stick with what they know and slag off anything unfamiliar.

Both manufacturers mention MuPVC as a flue option, but give no information whatsoever (eg design rules). Anyway, I've fired off an email to both of them asking for information.

On flues, I understand the whole length must be accessible for inspection. At one point mine will need to pop up through the 'ceiling' above the carport before turning to go horizontally over the top of the RSJ holding the back wall up. Presumably all I need do is provide a small hatch to shine a torch up through and check the joint is still intact ?

pampers wrote:

Keston are worse than you have heard truly a stack of steaming (well usally not steaming when i see em as they broken) poop.

So that's not an endorsement then

[Boilerman2]

There are Kestons, but there are no OLD Kestons!!!

[ChrisR]

Quote:

Beware of the cynics who will likely start posting when they read this!

It's Ok we know you're a stoolie from the Viessmann factory up the road from you
They're okay - nothing special and a bit expensive, not particularly reliable, come with a lot of hype ...

[gassafeengineer]

dont buy a keston ever never ever ever no way. do without heat before you get one of them

[jimstreet]

Baxi/potterton do the powermax boiler which uses twin flue, and this is not plastic flueing, its metal.

oh yeah and nearly forgot to slate keston boilers before i left!! i would rather have intimate relations with my dad, before fitting a keston, or reccomending them, they are awfull boilers!!

[SimonH2]

jimstreet wrote:

Baxi/potterton do the powermax boiler which uses twin flue, and this is not plastic flueing, its metal.

Twin flue isn't uncommon - the manuals for most of the boilers I've looked at have included details of twin flue setups. However, the flues are 80mm and so for me not much better that a standard 60/100 concentric flue. Actually, I think that's about the size of a plume diversion kit on most systems - so that could be one other option.

As far as I can tell, the Powermax is an attempt at an integrated thermal store & boiler - what little I can find on them isn't complimentary about their reliability

[jimstreet]

As far as I can tell, the Powermax is an attempt at an integrated thermal store & boiler - what little I can find on them isn't complimentary about their reliability [/quote]

yes simon, the powermax is a thermal store, but i have worked on a few powermaxes over the last few years, and pretty much all i have ever changed is pumps, and plate to plate h/e. so not too bad reliability

[kevplumb]

tbf

just about anything is better than a keston