Hard Water in Maidstone

Maidstone is a hard water area, and one of the harder ones in the country. The water is drawn from the chalk and greensand aquifers under this corner of Kent, and it reaches your stop tap carrying dissolved calcium and magnesium. Heat that water, or leave it to dry on a surface, and those minerals come back out as limescale. It is why kettles fur up here in weeks, why a shower screen never stays clear for long, and why a boiler in Maidstone works harder for its living than the same boiler would in Manchester.

You cannot change the water arriving in the street. You can decide where it is allowed to do its damage, and that decision is worth more money than most people realise. We are a Gas Safe registered and OFTEC certified plumbing and heating business based in Bearsted, a couple of miles out of the town centre, and hard water sits behind a large share of what we get called to. What follows is what limescale actually does inside a heating system, why your radiators are a completely different problem from your hot water, and which of the fixes on the market are worth paying for.

Why the water in Maidstone is hard

Rain falling on the North Downs soaks down through chalk, and chalk is calcium carbonate. By the time that water has been abstracted and treated it is carrying a good deal of dissolved mineral, and the greensand beneath the town does much the same thing. Nothing in the treatment process takes it out, because there is no health reason to. Hard water is perfectly safe to drink and plenty of people prefer the taste of it.

What it is not is kind to plumbing. It is worth looking up the hardness figure for your own postcode before you spend anything on the products further down, because the right answer for a house in Maidstone is not automatically the right answer everywhere in Kent, and the sums change with how hard your supply actually is.

What limescale does inside a boiler

Scale forms fastest where water is hottest. On a combi that means the plate heat exchanger, the compact stack of plates that takes heat off the boiler and puts it into your hot water on demand. Because a combi heats water instantly rather than storing it, that exchanger runs hot every time somebody opens a tap, and here it is being fed fresh hard water on every one of those occasions.

The early symptom is not a breakdown. It is hot water taking longer to arrive than it used to, or a shower that runs hot, cools off, then recovers. We have found that people live with that for a year or more before mentioning it, usually blaming the shower rather than the boiler, and by the time we see it the exchanger has normally scaled far enough that it needs replacing rather than cleaning.

Scale in the main heat exchanger is louder about it. It shows up as kettling, a rumble or a bang when the heating is working hard, which is water boiling against a scaled surface because the heat cannot carry away fast enough. That noise is a warning about an expensive component, and it is one of the few plumbing faults you can genuinely diagnose from the next room.

Why your radiators are a different problem

This is the distinction that saves people money, and almost nobody arrives already knowing it. Your central heating is a sealed circuit. The same water goes round and round for years, so it drops out whatever scale it was carrying once, early on, and then it is finished. What happens after that is not scale at all. It is corrosion.

Steel radiators, copper pipe and a metal heat exchanger sitting in water slowly produce magnetite, a black iron oxide sludge. That is what leaves radiators cold at the bottom and warm at the top, blocks pumps and jams valves, and it is what a power flush is for. Hard water does not cause it. Repeatedly adding fresh mains water does make it worse, which is why a system with a slow leak and an owner topping it up every month ages far faster than one that simply holds its pressure.

So a Maidstone house usually has two separate problems running at the same time. Scale on the hot water side, sludge on the heating side. They need different fixes, and a product that solves one does nothing whatsoever for the other.

Cylinders, immersion heaters and the bathroom

If you have a hot water cylinder rather than a combi, the exposure is different but no smaller. A cylinder holds a large volume of water at temperature for hours at a stretch, which is precisely the condition scale wants. On an indirect cylinder the coil scales up on the outside. On anything with an immersion heater, the element furs over until it is working inside a shell of limescale, drawing the same electricity to deliver less heat, and eventually failing altogether.

Bathrooms show it soonest because you look at them every day. Thermostatic shower cartridges seize, tap aerators block and start spraying sideways, and shower glass etches permanently if hard water is left to dry on it for a few years. When we quote a new bathroom in this part of Kent we raise it at the start, because dealing with it at first fix costs a fraction of replacing a scaled-up shower valve that is buried behind finished tiling.

Which fixes are actually worth the money

Three products get offered, they do three different jobs, and they are confused with each other constantly.

• A water softener removes the hardness. It is an ion exchange unit plumbed into the incoming main, usually under the kitchen sink or in a garage, and it takes the calcium and magnesium out before the water reaches anything. It needs salt topping up, and it needs one unsoftened tap left for drinking and cooking.
• A scale reducer conditions the water rather than changing what is in it. It does not remove hardness, it discourages scale from sticking. Cheaper, smaller, no salt and no drain connection, and less effective.
• A magnetic filter sits on the heating return and catches magnetite. It does nothing at all about limescale, because it is solving the other problem entirely.

In our experience, a proper water softener works better than an inline scale reducer in a Maidstone house with a hot water cylinder, because a reducer only treats water as it passes and a cylinder holds it hot for hours, which is exactly when scale forms.

That does not make a softener right for everybody. On a combi in a small flat, where no water sits hot for any length of time, a scale reducer and a yearly service will usually keep you out of trouble for a lot less money. The honest way to decide is by what you are protecting. If there is a cylinder upstairs, the sums favour the softener. If there is not, they often do not.

What we find on Maidstone jobs

A few patterns repeat often enough to be worth naming.

• A scale reducer fitted years ago and never thought about again. Several types are consumable and need replacing, and a spent one sits there doing nothing while everyone assumes the problem is handled.
• A softener that ran out of salt at some point in the last two winters. It looks fine, it makes no noise about it, and it has been passing hard water ever since.
• An immersion heater that failed and was quietly ignored because the boiler still heats the water. The element is usually solid with scale by the time it comes out.
• Hot water complaints on a combi that get blamed on the shower. We are asked to look at the shower, and the shower is fine.

The last of those is the most common call we take in the ME14 and ME15 postcodes, and the giveaway is easy enough to check yourself. Run the hot tap at the basin nearest the boiler, time how long it takes to get properly hot, and compare that against how long it used to take. If it has crept up and the flow has dropped off, the problem is upstream of the bathroom.

What to actually do about it

Servicing earns its keep here in a way it does not in a soft water area, because servicing it every year catches a scaling exchanger while it is still an early symptom rather than a replacement part on a cold morning in January.

Beyond that, start by finding out how hard your water genuinely is, then decide by what you are protecting rather than by whichever product you were shown first. Put a magnetic filter on the heating side whatever you decide, because it is cheap and it is solving the other problem. If your system keeps losing pressure, get the leak found instead of topping it up, since every top up brings fresh oxygen and fresh mineral into a circuit that was designed to be sealed. And treat hot water performance that is slowly getting worse as information rather than something to put up with.

Hard water in Maidstone is not a fault to be fixed, it is a condition to design around. The houses that get an easy ride from it are the ones where somebody made a deliberate decision about it. The ones that do not are almost always the ones where the question never came up until something failed. We work across Maidstone and the rest of Kent from Bearsted, with free home visits and free quotes across Kent. If you want an honest view on whether a softener is worth it in your house, or your hot water has quietly got worse, get in touch.