A How to Guide on How to Repressurise a Keston Boiler

Whether your Keston boiler is brand new or has been keeping your home cosy for years, losing pressure is one of those things that just happens from time to time.

However, repressurising your Keston boiler is a quick and simple job that you can probably handle yourself, and there is no need to panic or call in the pros just yet.

If you have to repressurise your boiler more frequently, there are many reasons why it might be losing its pressure. However, no matter what the cause, you must deal with the boiler pressurisation problem as soon as possible.

So, how does one repressurise a Keston boiler?

Step-By-Step For Repressurising A Keston Boiler

All boiler manufacturers, including Keston, will ensure their units’ repressurising is as simple as possible.

The ideal pressure level for a Keston Boiler is between 1 to 1.5 bars when cool.

If the pressure drops below one bar, the system will usually shut down and notify you that it needs to be repressurised. You should bleed your radiators if the pressure level is above two bars.

With Keston boilers, if the pressure does drop below 0.3 bars, it will stop working.

As mentioned, repressurising a Keston Boiler is straightforward. Here’s the first step you need to take to repressure a Keston Boiler:

Step 1: Turn Off the Boiler

When working on your boiler, you must ensure it is off.

Switching off your Keston boiler prevents the danger of boiling water, and letting it cool for at least an hour allows you to get a more accurate pressure reading.

You can turn off your boiler by flipping the main switch, or if you are in doubt, you can also flip your home’s circuit breaker.

Step 2: Locate the Filling Loop

You need to use a filling loop to repressurise your boiler’s heating system.

There are two common types of filling loops which are:

• External filling loop: A detachable, braided silver hose.
• Internal filling loop: Built into the boiler, usually operated with a key or lever.

You will use a solid (external) filling loop for Keston boilers, which should be stored under the unit.

Step 3: Attaching Filling Loop

When attaching your Keston filling loop, check if the valves are closed. These valve handles are blue and closed when positioned at a 90-degree angle from the pipe’s direction.

To attach the filling loop, you must remove the plug and cap, setting them aside for later use.

Attach the filling loop to the domestic hot water inlet and tighten it securely by hand. Do not over-tighten, as this can create leaks.

Step 4: Open The Filling Loop Valves

When ready, open the first valve by moving it to align with the filling loop pipe. Then, slowly open the second valve and allow the water into the boiler’s heating system.

When your boiler’s pressure gauge reaches 1 to 1.5 bars, you must close the valves.

Step 5: Cleaning Up And Checking

You must disconnect a Keston boiler’s external filling loop. When removing the loop, ensure a bucket and towels are handy, as some water will spill.

Now, you should be ready to use your repressurised Keston boiler. However, if you need to repeat this process within a few hours, days, or every week, you could have a more serious pressure problem.

But what are the common causes a Keston boiler may be losing its pressure?

Why Your Keston Boiler May Be Losing Its Pressure

All boilers will lose pressure from general use. For this reason, manufacturers make the repressurisation process as simple as possible.

But as mentioned, if you are having to repressurise your boiler more frequently, there are several common reasons why this could be happening, which include the following:

Leaks in the System

Even the tiniest leak in a boiler’s system can cause it to lose pressure quickly and force your unit to shut down.

Leaks in your boiler’s system can also happen anywhere, so narrowing down where it is can be difficult. But make sure to be on the lookout for common signs, which include the following:

• Damp patches on walls, ceilings, or radiators are a telltale sign something’s not right.
• Strange gurgling or hissing noises coming from your system like it’s trying to tell you there’s a problem.
• Finally, a noticeable spike in your water usage, even if nothing else has changed.

Locating a leak can be difficult and can require help from a Gas Safe registered engineer.

Insufficient System Inhibitors

Your boiler’s heating system needs the correct level of chemical reaction inhibitors to stop the formation of sludge. Sludge is a mixture of rust, calcium, silica, and other organic matter.

If your system’s inhibitors are not correctly balanced, sludge can cause blockages, which can cause your boiler’s pressure to drop because water is not circulating.

Your system’s inhibitor level might be poorly balanced because the homeowner has topped up pressure levels with water.

To correct this, get your Gas Safe registered engineer to top up on your boiler’s chemical inhibitors.

Indicators that this is the cause for your Keston boiler losing pressure are:

• Cold spots on radiators.
• Frequent pressure drops.
• Decreased heating efficiency.

Faulty Boiler Pump Or Expansion Vessel

If your boiler’s pump or expansion is faulty, you must contact a Gas Safe registered engineer to fix it. By law, only a Gas Safe registered engineer can replace or repair components within your home’s boiler.

As you can imagine, there are different symptoms between a boiler’s pump and expansion breaking down.

A broken boiler pump will cause the pump to overheat or leak within the unit. Also, your home’s radiators will not heat up evenly.

If your expansion vessel is broken, you will see pressure spikes followed by sudden drops and water escaping through the pressure relief valve.

Putting off repair work to your boiler that is losing pressure can be costly. A damaged boiler that frequently loses pressure is inefficient with heating (higher running costs) and will cause more damage to your unit and system over time.

Calling professional help as soon as possible is essential to saving your Keston Boiler and money, but who should you call?

Call in WarmZilla’s Gas Safe-Registered Engineers

If repressurising your Keston boiler has confirmed you need help, don’t worry. WarmZilla has covered you.

Our Gas Safe registered engineers can:

• Inspect for leaks,
• Replace faulty components
• Perform system flushes
• Make repairs.
• As well as restoring your boiler’s performance quickly and efficiently.

With our extensive coverage across the UK, we can help you within 48 hours, so you won’t be left out in the cold.

If you have any unanswered questions, feel free to contact our team of call centre professionals.