Topping up the pressure on your Ideal Boiler

Important Disclaimer: This article is a general guide to help homeowners understand how to repressurise a boiler system. Instructions may vary depending on your boiler model and system type.

Always consult your manufacturer’s manual before proceeding. If you are unsure at any stage, or if your boiler frequently loses pressure, you should seek assistance from a qualified heating engineer.

Over-pressurising or incorrectly operating your system may cause damage. We cannot accept responsibility for any issues arising from the use of this information.

The normal operating water pressure for your boiler and central heating system is between 1.0 and 2.0 bar.

If the pressure drops below 1.0 bar, you need to repressurise it. On the pressure gauge on the front of your boiler, the needle will be in the centre of the green triangle on the dial. When your boiler is heating up your hot water or radiators, the needle will go up a little but should not go higher than about 2.5 bar.

The needle should stay in the green section. If it is too high, a safety valve is fitted that will discharge water to keep the pressure at a safe level. You may need to bleed your radiators to reduce the pressure in the system.

First, you will need to locate the filling loop, typically this is located alongside or below your system.

If you cannot locate the loop, you may need to consult your manual where it may be located. Second, you will need to make sure that your system is cold and that your boiler is switched off. On either side of the loop, there will be a lever, these are used to control the amount of water in the system. The more water in the system the more pressure. It's very important that you keep an eye on the pressure gauge for the next step as if it gets too high or too low it can damage the system. Thirdly, you will want to slowly turn either of these levers watching the pressure gauge closely as you do. You will need to open both taps to balance out the pressure. Once you have hit between, 1 and 1.5 bar then you will want to close the levers. Make sure these levers are fully closed as otherwise, pressure will continue to rise in the system. Once this is complete, it is safe to turn your system back on.

Is Your Pressure Dropping Frequently?

While it is normal to top up your pressure occasionally, doing so frequently (e.g., once a month or more) could indicate a small leak in your system or a faulty pressure relief valve.

Check Your Radiators: Bleeding your radiators can help stabilise system pressure.
Monitor the Gauge: If the needle continues to drop below 1.0 bar, consult a Gas Safe engineer.
Understand Your Model: Different boilers have different filling loop styles. Check your boiler model name for specific instructions.

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