In many areas of the UK, such as the Thames Valley, Kent and East Anglia in particular,
rain water will pass through rocks that contain calcium and magnesium. The water
that filters through these rocks will partially dissolve these minerals. Your water
supplier will remove this underground water, clean it, and send it to homes across
your region. But the dissolved minerals remain. When the water is heated (especially
over 63 degrees C) the calcium deposits will fall out of the water and adhere to
surfaces. This is what's commonly called 'limescale'. It’s highly damaging to water
heating equipment and costs consumers millions of pounds per year.
However, you don’t have to resort to fancy ideas of protecting water systems from
the damaging effects of limescale. Water softeners are all well and good. But they
are expensive, and require constant salt replenishment and maintenance. The problem
with non-physical water conditioners, such as those that use electronic signals,
is that they seem largely unproven, and manufacturers of these units are conspicuously
reluctant to offer a money-back guarantee if they don’t work. Polyphosphate inhibitors
almost exclusively use a ‘dosing’ unit which has tiny holes for the water to flow
in and out. However, the holes block up with the powdery polyphosphate!
We have carried out research for many years on what works and what doesn’t. Over
thirty years of attending to hot water appliances that are encrusted with limescale
has revealed that there really is only one choice - Siliphos, silicate-polyphosphate.
A Siliphos dispenser doses the water with silicate-polyphosphate. So in 2003 we set
out to find the perfect Siliphos dispenser for combi boilers - and, after constant
improvement, the CombiBuddy (and LimeStop) is the result. It’s copper rather than
plastic, it has brass isolating valves, and there’s no need to replace the Siliphos!
Siliphos is a widely-trusted food-grade material proven time and again to inhibit
limescale formation. Its ability to combat limescale deposits is really quite remarkable
as it both lays down a protective layer on the walls of the supply piping and inhibits
calcium deposits. The CombiBuddy is a copper cylinder packed with Siliphos, which
can be fitted prior to ANY combination boiler. It's even suitable for drinking water!
It is supplied with two isolating valves, making replacement of the unit (every 2
years - at a discounted rate) quite literally a 5-minute job! We’ll even remind you
when replacement is due. If you want to protect a whole-house installation, then
opt for the LimeStop instead (see HERE). The LimeStop is a larger version of the
CombiBuddy for whole-house water treatment.
The CombiBuddy is guaranteed to work...or your money back!*
What is the cost of the CombiBuddy?
£69.00 + postage.
What will be the annual cost of the CombiBuddy?
Your replacement cost is £64.00 (+ postage) after two years, so the annual cost is
from £32.00...just 8p a day...to stop limescale form ever forming in your combi boiler.
Exchanging the unit is only a 5-minute job for a plumber, and you may even be confident
enough to do it yourself.
How much does it cost to install?
It should cost anything from £25 to £50 plus any fittings that your installer may
need - although it is usually a straight fit, without any need for fittings. We charge
£50 to fit a CombiBuddy - in the RG postcode area.
What's the length of the CombiBuddy?
What's the width?
What does it weigh?
What's it made of?
Copper, with brass fittings.
What's inside that inhibits limescale?
Siliphos, a food grade material called silicate-polyphosphate.
How does it inhibit limescale?
As water flows through the CombiBuddy it flows over the spheres of Siliphos - and
they give up a slight amount of their coating. Siliphos inhibits limescale in two
ways. First of all it makes the calcium molecules stay in suspension, rather than
stick. Secondly it lays down a layer of silicate on the walls of pipes etc. This
too helps to inhibit limescale sticking.
How much Siliphos is in there?
Approximately 380 grams
Why that particular amount?
Because it's the optimum amount to ensure limescale inhibition in domestic appliances.
Should it be fitted horizontal or vertical?
Either, though vertical is ideal. If fitting horizontally, then it should be installed
Does the Siliphos 'run out' of its effectiveness?
Yes. We recommend replacing the CombiBuddy after two years. We will send you a reminder
when that time is up.
Can I replace it easily?
Yes. Simply remove the compression nuts with a suitable spanner and fit the new one
on in the same manner. We supply isolating valves so that you can do this as easily
as possible. It’s a five minute job to do. Some of our customers ask their boiler-service
engineer to do it while he is there. Make him a nice cup of tea, if you like, but
the job will be done before the kettle has boiled.
Can't I just replace the Siliphos?
Replacing the Siliphos in any Siliphos-dispenser for an appliance isn't usually a
straightforward job. There's also the likelihood of leaks afterwards. So we opted
for a replaceable unit, rather than one which can be refilled. We trialled different
options but found that this was ideal. It means you don't have to try and buy Siliphos,
and there's no messy, soggy used Siliphos to bother with. We've made the CombiBuddy
for an excellent price, so that it's actually economic to discard it and replace
it with another unit. We charge £45 to replace it for you (RG area only), and your
engineer may charge you about the same.
Is the water drinkable?
Yes, Siliphos is a non-hazardous food-grade material. It conforms to EN1208:2005
(Treatment of water intended for human consumption) and WHO standards for drinking
water supplies. Unlike artificially-softened water, it's safe for babies too. The
CombiBuddy unit itself is just copper (like your pipes). The fittings used are brass
(standard pipe fittings). There’s no requirement for the CombiBuddy to be WRAS approved
for use with mains water drinking supplies as it is made of copper and brass with
an approved food-grade material. WRAS is the Water Regulations Advisory Scheme
Do you supply a ‘check valve’ anyway?
Yes, we do. It’s in the box.
Is the CombiBuddy classed as a water softener?
No, the hardness is still there, it's just suspended. This is true of all limescale
inhibitors; if it doesn't actually remove the 'hard' salts then it's not a water
softener. We actually prefer to call it a water conditioner, but ‘limescale inhibitor’
is the often-used term.
If the treated water is then stored, will it still be effective?
The effect diminishes with time. All such limescale inhibitors only ever affect moving
water. The sooner the stored water is used, the better.
Your instructions say not to fit the CombiBuddy too close to the boiler, why?
Warm water backfeeding down the supply will degrade the Siliphos. Its period of effectiveness
would be less.
Can I fit it in a warm cupboard?
Yes, but not if the ambient temperature is above 30 degrees C for the same reasons
as above. Also, fit it low down in the cupboard where the cold mains enters.
Will it protect mains thermal store appliances?
For that we recommend a LimeStop. Most mains thermal stores use a coil of mains cold
water that is heated by surrounding hot water. This is increasingly common. However,
such units rapidly 'scale-up' in hard water areas. See www.limestop.co.uk
Will I still get limescale around my showerhead?
Most possibly, yes. This is because the Siliphos-effect will stop your shower scaling-up,
but 'still' water will be left on the showerhead and around taps etc. The effect
will be lost and deposits may well occur.
What will the CombiBuddy protect?
The CombiBuddy is ONLY made for fast-flowing mains water, and is thus ideally suited
to combination boilers. It can also be used to protect electric showers, etc.
Can I fit it to a conventional hot water cylinder?
No, this would be a stored system.
Can I fit it on my central heating system?
No, it is made for mains cold water supplies, not central heating. You shouldn't
get any limescale in your heating system providing it has been installed correctly.
If you want to stop magnetite sludge (black, oily substance) then fit one of our
What size ports has the CombiBuddy got?
The CombiBuddy is supplied in 15mm as standard.
What if I have ¾" or 22mm water supply?
This would be unusual, as combi boilers almost always have a 15mm water supply -
so check and make sure before you order. Just measure the width of the supply pipe.
If in doubt, email us.
Will my water pressure be reduced?
The CombiBuddy is a through-flow unit, and you would not see any noticeable drop
in water pressure or flow after fitting.
Will the CombiBuddy withstand high water pressures?
Yes. Unlike some plastic units, which are tested to 10 bar, the CombiBuddy - being
made of copper - will withstand extraordinarily high pressures.
What is limescale?
It's dissolved rock. Rain water dissolves the calcium and magnesium out of the rock.
This water is then treated and sent to your home. When the water is heated the dissolved
particles re-solidify and stick to the walls of the heat exchanger. It will do this
at low temperatures, but it really begins at anything above 63 degrees C.
Is limescale harmful?
To your heating appliances, yes, very! Even a slight coating of it will reduce the
efficiency of your appliance, meaning your energy bills will be higher. It also causes
premature failure of key components.
Do you guarantee that the CombiBuddy works?*
Yes. Our guarantee is that the secondary (hot water) heat exchanger of your combi
boiler will not suffer from 'scaling-up'. If it did then we would refund the initial
purchase cost. We believe all limescale inhibitors should carry a performance guarantee.
Don't buy one that hasn't got a money-back guarantee.
Any clauses to that?*
Yes, you must have had the unit at least two years, and obviously that you had replaced
it at the recommended intervals. You would be required to provide proof of purchase.
Why is the CombiBuddy better than other limescale inhibitors?
The CombiBuddy requires no electricity or maintenance. It doesn't use magnets or
questionable electromagnetic waves. It uses a time-proven material that we feel good
enough to offer our performance guarantee of your money back. However, it also goes
a few better than very similar units because it's metal, not plastic, and doesn't
require that you fiddle with large 'O' rings and wet Siliphos! You may be aware of
a very similar unit to ours, but it requires 6-monthly topping up, and annual cleaning,
and Siliphos replacement. With ours you simply replace it every two years, having
a nice clean one ready to go for minimum fuss. It’s recyclable, as it’s copper.
Have you ever had to give anyone their money back due to an appliance re-scaling?
How much is it?
£69.00 plus postage
And when it’s ready to be replaced?...
We contact you.
Do you give a discount if I buy more than one?
Yes, please email us.
Is the CombiBuddy a British product?
Yes, we're proud to say it is. It is a quality product hand-made in England, not
China - like so many similar units.
I have soft water, so surely I don’t need a CombiBuddy?
The CombiBuddy can even be used in soft water areas, as the Siliphos lays down a
protective coating on the walls of the supply piping - thus preventing acidic-water
attack and so-called ‘Blue Water’.
Why don’t you sell the CombiBuddy in plumbing merchants?
Because by the time they have added their mark-up charge, it would make it too expensive.
You get it the cheapest possible by buying direct from us.
I want one.
Then click HERE Just let us know your telephone number, and we’ll phone YOU to arrange
re-routing piping, yet fits away from other pipework on two angled isolating valves
We can ship worldwide
Our products are
Due to issues with UPS and Parcel2Go we will be using the Post Office and Parcel
Force from January 10th.
3 days, signed for
1 day, signed for
Guaranteed by 1 p.m. Next working day
Guaranteed by 9 a.m. next working day
Prices shown are for single CombiBuddys. For larger orders, we would quote you.
In plain and simple:
Purchase cost £69 + postage
Likely labour to install £45
Replacement cost £64 + postage
Likely labour to replace £45
The guarantee against ‘scaling-up’ is dependent on the CombiBuddy being installed
for at least two years. If your combi boiler should ‘scale-up’ to the detriment of
water flow (we would require proof to satisfy such an occurrence), then we would
return the original purchase price (£69.00) to the original purchaser. Your statutory
rights are not affected.
Please be aware that items are usually sent by ‘3-day’ service. If you need it urgently,
the postage costs are shown above.
Cancelling & Returns
Cancelling your order before we send it:
Simply contact us by letter or email to cancel - any money already taken will be
returned to your bank account by bank transfer within seven days. Our cancelling
policy is ‘no quibble’.
Cancelling your order after we have sent it:
If you have already been sent the product then we would aim to reimburse you within
seven days of us receiving the product back from you. Please note that under the
Consumer Contracts Regulations you do NOT have the right to return the product and
claim a refund if you have unsealed the box (due to hygiene reasons). However, if
the product is still in its sealed box, you have the right to return it up to 14
days after you receive delivery. You should send the product back via a reliable
courier, and in its original packaging. If you cancel before you receive the product
then obviously there will be no charges made. If, however, you cancel after the product
has been sent to you, then you are liable for the postage costs in returning the
product to us. You should retain proof of posting, but please be aware that it is
incumbent upon you to ensure that we receive it, so we would advise you to require
a signature of delivery. Your cancelling email/letter must include the following:
(copy & paste):
I hereby give notice that I wish to cancel my order for the following goods...............
Signature (if letter sent)............................
So many engineering products are made in China now...but not ours! Manufacturers
do this because labour costs are very low there, but then so is quality. We’ve seen
products with ‘British’ advertised on them, only to discover that the product was
designed in Britain, by a British company, but then made in China from Chinese components!
We are a British business. But we go much further than that - we actually make our
products here; we are supporting British manufacturing and British jobs. We will
go on doing that because we are sincere about quality - we insist on it ourselves.
Quality ensures reliability. We could easily make our products from plastic - it
would make them much cheaper. But quality would suffer, and so would reliability.
We hope that you’re looking for the best product, not the cheapest.
We want to ensure that you are happy with our service, and that we have been fair
and professional. And we ask that you too are fair in ordering products from us.
Sometimes, packages go astray within the post. We have to claim against the courier
in such circumstances (rare, though they are), and we would not be able to post you
a replacement until we get confirmation from the courier that the item has indeed
been lost. We ask you to be patient, and to work with us to resolve the problem.
We would talk to you by phone to reassure you, and keep you up to date with any information
we have. We would even give you the details of the courier to prove that the item
had indeed been mislaid or lost.