I am thinking about having my old, inefficient but reliable gas
boiler replaced next summer. I have been reading manuals and other
web resources, mainly looking at German and Dutch manufacturers.

The review of the Giannoni stainless steel heat exchanger at
www.gas-news.co.uk/archive/storage/pre-10/2007/comment/1006.htm
does not fill me with confidence -- too much plastic, and no way to
strip it down to clean it.

On the other hand, cleaning the Worcester WB3 aluminium heat exchanger
at www.gas-news.co.uk/archive/storage/2008/comment/1001.htm seems
labour intensive, particularly if it is needed every year.

I have been looking at the Dutch company Remeha (Broag, their UK
importers, are just down the road). I believe the Avanta has a
Giannoni heat exchanger, while the Quinta has a cast aluminium heat
exchanger.

I prefer the look of the Quinta -- it seems more solidly built and
accepts an external 0-10v modulating input if I wanted to update the
system controls later. However, I am wary of the aluminium heat
exchanger.

Now that condensing boilers have been around for a few years, what are
people's experience with the relative life and cost of maintenance of
aluminium vs. stainless steel?

Regards,

MJA

"MJA" wrote in message
...
I am thinking about having my old, inefficient but reliable gas
boiler replaced next summer. I have been reading manuals and other
web resources, mainly looking at German and Dutch manufacturers.

The review of the Giannoni stainless steel heat exchanger at
www.gas-news.co.uk/archive/storage/pre-10/2007/comment/1006.htm
does not fill me with confidence -- too much plastic, and no way to
strip it down to clean it.

On the other hand, cleaning the Worcester WB3 aluminium heat exchanger
at www.gas-news.co.uk/archive/storage/2008/comment/1001.htm seems
labour intensive, particularly if it is needed every year.

I have been looking at the Dutch company Remeha (Broag, their UK
importers, are just down the road). I believe the Avanta has a
Giannoni heat exchanger, while the Quinta has a cast aluminium heat
exchanger.

I prefer the look of the Quinta -- it seems more solidly built and
accepts an external 0-10v modulating input if I wanted to update the
system controls later. However, I am wary of the aluminium heat
exchanger.

Now that condensing boilers have been around for a few years, what are
people's experience with the relative life and cost of maintenance of
aluminium vs. stainless steel?

The Quinta is a commercail boiler, so more expensive. At this point
consider a system update. How about a quality high flow combi, giving high
pressure showers? The Broag 39C combi will do in most cases.

Have a Magnaclean on the return to the boiler. That will prevent any
blocking up of the tubes in the heat exchanger.

The Broag, has a 5 year guarantee. They use primarily industry standard
components and little plastic with Honeywell brass hydrobocks. The Broags
are better quality than Vaillant and much cheaper. They are a well priced
quality boilers having a superb control system with integrated outside
weather compensation and OpenTherm control protocal control.
http://www.avantaplus.co.uk

http://www.tradingdepot.co.uk/DEF/ca...meha%20Boilers

The control options. Wiring the combis is simple:
http://www.avantaplus.com/docs/Issue...%20Booklet.pdf

Go for the Avantaplus range.

Now what is your system like? Cylinder? vented? how many showers? Baths,
etc. Then it can be whittled down to what you really need. It is no good
putting a modern boiler on an outdated DHW/CH system. Go for gold.

On 2008-12-12, Doctor Drivel wrote:

"MJA" wrote in message
...

I am thinking about having my old, inefficient but reliable gas
boiler replaced next summer. I have been reading manuals and other
web resources, mainly looking at German and Dutch manufacturers.

some text trimmed

I prefer the look of the Quinta -- it seems more solidly built and
accepts an external 0-10v modulating input if I wanted to update the
system controls later. However, I am wary of the aluminium heat
exchanger.

Now that condensing boilers have been around for a few years, what are
people's experience with the relative life and cost of maintenance of
aluminium vs. stainless steel?

The Quinta is a commercail boiler, so more expensive. At this point
consider a system update. How about a quality high flow combi, giving high
pressure showers? The Broag 39C combi will do in most cases.

We've had a few water outages in my part of the Thames Valley, and I
also like having the backup immersion heater. Space for tanks is no
problem.

Have a Magnaclean on the return to the boiler. That will prevent any
blocking up of the tubes in the heat exchanger.

The Magnaclean is worth considering -- although the system seems
fairly clean and has had inhibitor in.

The Broag, has a 5 year guarantee. They use primarily industry standard
components and little plastic with Honeywell brass hydrobocks. The Broags
are better quality than Vaillant and much cheaper. They are a well priced
quality boilers having a superb control system with integrated outside
weather compensation and OpenTherm control protocal control.
http://www.avantaplus.co.uk

Yes, I have looked at the Avanta and Quinta instructions. I am wary
of OpenTherm because the interface specs are not published -- same
problem for Vaillant and eBus. A standard 0-10v input seems future
proof -- that limits me to the Quinta 30, Keston Qudos or MHG with
option module.

Now what is your system like? Cylinder? vented? how many showers? Baths,
etc. Then it can be whittled down to what you really need. It is no good
putting a modern boiler on an outdated DHW/CH system. Go for gold.

Current system original when 3 bed bungalow built in mid 1970's. Gas
boiler Potterton C55 cast iron, floor standing, conventional flue,
55,000 Btu output, which is adequate given the insulation improvements
since the bungalow was built. Conventional hot water system --
indirect tank in airing cupboard, primary gravity circulation, open
vent with Honeywell "C" system added by previous owner. One bathroom,
bath with gravity fed shower over. One-pipe pumped central heating
circuit, hall thermostat added by previous owner.

The economics of an upgrade are finely balanced. Current running
costs are about 700 pounds fuel, plus 60 pound annual boiler service.
A new boiler could be cost neutral over 10 years assuming a fuel
saving of 250 pounds per year and 2500 for new boiler, installation
and essential system changes. Higher maintenance costs would put me
off the change, higher gas prices could make it worthwhile.

The old boiler is supremely reliable, and I would hate to find I had
swapped it for something as unreliable as the Worcester Firefly HD II
my father had years ago -- the flame sensor probe positioning was
critical so it regularly locked out leaving us to return to a cold
house, and it burnt through glow-plugs every few months.

I asked about stainless steel versus aluminium as the boiler choice
FAQ at www.makewrite.demon.co.uk/BoilerChoice.html views aluminium as
questionable, even though many manufacturers use it (Remeha Quinta,
Buderus, Worcester, etc.). The boiler choice FAQ mentions one
incident of aluminium corroding on the water side -- is this a problem
nowadays with correct inhibitors?

Regards,

MJA

"MJA" wrote in message
...
On 2008-12-12, Doctor Drivel wrote:

"MJA" wrote in message
...

I am thinking about having my old, inefficient but reliable gas
boiler replaced next summer. I have been reading manuals and other
web resources, mainly looking at German and Dutch manufacturers.

some text trimmed

I prefer the look of the Quinta -- it seems more solidly built and
accepts an external 0-10v modulating input if I wanted to update the
system controls later. However, I am wary of the aluminium heat
exchanger.

Now that condensing boilers have been around for a few years, what are
people's experience with the relative life and cost of maintenance of
aluminium vs. stainless steel?

The Quinta is a commercail boiler, so more expensive. At this point
consider a system update. How about a quality high flow combi, giving
high
pressure showers? The Broag 39C combi will do in most cases.

We've had a few water outages in my part of the Thames Valley, and I
also like having the backup immersion heater. Space for tanks is no
problem.

Have a Magnaclean on the return to the boiler. That will prevent any
blocking up of the tubes in the heat exchanger.

The Magnaclean is worth considering -- although the system seems
fairly clean and has had inhibitor in.

The Magnaclean is essential on a Gianonni heat exchanger and on any system.

The Broag, has a 5 year guarantee. They use primarily industry standard
components and little plastic with Honeywell brass hydrobocks. The Broags
are better quality than Vaillant and much cheaper. They are a well priced
quality boilers having a superb control system with integrated outside
weather compensation and OpenTherm control protocal control.
http://www.avantaplus.co.uk

Yes, I have looked at the Avanta and Quinta instructions. I am wary
of OpenTherm because the interface specs are not published -- same
problem for Vaillant and eBus. A standard 0-10v input seems future
proof -- that limits me to the Quinta 30, Keston Qudos or MHG with
option module.

The Avantaplus system boiler is a "Dual Temperature" boiler. High temp to
re-heat DHW and resorts to weather compensation after. An external 3-way
valve is controlled by the boiler for this.

How long were water outages? These are usually not very long, so are you
over exaggerating? You can keep the tank and supply the toilets only with
this so it gives toilet backup in case of a failure. An in-line instant
electric water heater in the combi outlet gives backup and can do the shower
and one tap until the combi is backup. Get you wet enough. About £100-110.
This is a small box that can go in the loft

The one-pipe system may be a problem on most boilers. A restricting gate
valve usually solves it, as the pumps are too fast and pump past the rads.
Many installer will not touch them and insist on ripping it out and putting
in a two-pipe system.

I would go for a Broag 35C or 39C combi that gives powerful showers and no
pumps and get rid of the cylinder (on its last legs after 30 odd years) and
tanks.

The boiler FAQ is 20 years out of date and don't take it too seriously.
Aluminium fitted in a clean system and treated properly every 4 years is
fine. It is silicon coated.

But I strongly suggest you go for the Broag 35C or 39C combi using the
weather compensation - integral with boiler. Cheaper installation, cheap to
run, quality and reliable. And backup if want.

"Doctor Drivel" wrote in message
...
It is no good putting a modern boiler on an outdated DHW/CH system. Go
for gold.

I'm interested in what you define as an outdated DHW/CH system. For instance
I have a Y plan system with a Honeywell optimising thermostat. If I
installed a new boiler what changes, other than a more efficient bolier, is
going to make a difference?

On Sat, 13 Dec 2008 12:02:55 +0000, MJA wrote:

On 2008-12-12, Doctor Drivel wrote:

"MJA" wrote in message
...

I am thinking about having my old, inefficient but reliable gas boiler
replaced next summer. I have been reading manuals and other web
resources, mainly looking at German and Dutch manufacturers.

some text trimmed

I prefer the look of the Quinta -- it seems more solidly built and
accepts an external 0-10v modulating input if I wanted to update the
system controls later. However, I am wary of the aluminium heat
exchanger.

Now that condensing boilers have been around for a few years, what are
people's experience with the relative life and cost of maintenance of
aluminium vs. stainless steel?

The Quinta is a commercail boiler, so more expensive. At this point
consider a system update. How about a quality high flow combi, giving
high pressure showers? The Broag 39C combi will do in most cases.

We've had a few water outages in my part of the Thames Valley, and I
also like having the backup immersion heater. Space for tanks is no
problem.

Have a Magnaclean on the return to the boiler. That will prevent any
blocking up of the tubes in the heat exchanger.

The Magnaclean is worth considering -- although the system seems fairly
clean and has had inhibitor in.

The Broag, has a 5 year guarantee. They use primarily industry standard
components and little plastic with Honeywell brass hydrobocks. The
Broags are better quality than Vaillant and much cheaper. They are a
well priced quality boilers having a superb control system with
integrated outside weather compensation and OpenTherm control protocal
control. http://www.avantaplus.co.uk

Yes, I have looked at the Avanta and Quinta instructions. I am wary of
OpenTherm because the interface specs are not published -- same problem
for Vaillant and eBus. A standard 0-10v input seems future proof --
that limits me to the Quinta 30, Keston Qudos or MHG with option module.

Now what is your system like? Cylinder? vented? how many showers?
Baths, etc. Then it can be whittled down to what you really need. It
is no good putting a modern boiler on an outdated DHW/CH system. Go
for gold.

Current system original when 3 bed bungalow built in mid 1970's. Gas
boiler Potterton C55 cast iron, floor standing, conventional flue,
55,000 Btu output, which is adequate given the insulation improvements
since the bungalow was built. Conventional hot water system -- indirect
tank in airing cupboard, primary gravity circulation, open vent with
Honeywell "C" system added by previous owner. One bathroom, bath with
gravity fed shower over. One-pipe pumped central heating circuit, hall
thermostat added by previous owner.

The economics of an upgrade are finely balanced. Current running costs
are about 700 pounds fuel, plus 60 pound annual boiler service. A new
boiler could be cost neutral over 10 years assuming a fuel saving of 250
pounds per year and 2500 for new boiler, installation and essential
system changes. Higher maintenance costs would put me off the change,
higher gas prices could make it worthwhile.

The old boiler is supremely reliable, and I would hate to find I had
swapped it for something as unreliable as the Worcester Firefly HD II my
father had years ago -- the flame sensor probe positioning was critical
so it regularly locked out leaving us to return to a cold house, and it
burnt through glow-plugs every few months.

I asked about stainless steel versus aluminium as the boiler choice FAQ
at www.makewrite.demon.co.uk/BoilerChoice.html views aluminium as
questionable, even though many manufacturers use it (Remeha Quinta,
Buderus, Worcester, etc.). The boiler choice FAQ mentions one incident
of aluminium corroding on the water side -- is this a problem nowadays
with correct inhibitors?


The silicon coated stuff /should/ be OK. I've put in a few and they seem
OK.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

"Mark Dumbrill" wrote in message
...
"Doctor Drivel" wrote in message
...
It is no good putting a modern boiler on an outdated DHW/CH system. Go
for gold.

I'm interested in what you define as an outdated DHW/CH system. For
instance I have a Y plan system with a Honeywell optimising thermostat. If
I installed a new boiler what changes, other than a more efficient bolier,
is going to make a difference?

There was clues.
Is your cylinder a quick recovery type?
Are your rads rated for a 60-40 temp differential?