Overfilling your central heating system is the most common cause of high pressure. It occurs when you repressurise your system by turning the valves on the filling loop. If you leave the filling loop valve open for too long it will draw too much water into the system, creating an overly pressurised system.

What happens if pressure is too high on boiler?

If the boiler pressure is too high, there’s an increased chance of leaks developing in the system. But if boiler pressure is too low, the system won’t work as well. So keeping the correct boiler pressure is important to make sure that your system heats your home efficiently.

Why is my boiler pressure increasing?





Combi boiler pressure increases when the heating is on as your boiler uses fuel (gas, oil etc) to heat the water – this increase in pressure is natural. If your boiler is behaving as it should, the pressure will stabilise again once the system is switched off and cooled down.

How do I stop boiler pressure from rising?

Heating systems often have a filter that cycles through water and removes any impurities. This filter and its valve can also act as a drainage system. If you suspect you have an overfilled boiler, open the filter valve to drain some of the water out and stabilise the system’s pressure.

Can a boiler explode from high pressure?

High pressure is rarely the reason for a boiler explosion, but various other reasons such as faulty internal parts can cause it.

Is 3 bar boiler pressure too high?

High boiler pressure isn’t dangerous, even if it’s showing as three bar on the pressure gauge. In most cases, the boiler will turn itself off if the pressure goes about a certain level and a working PRV should successfully control the pressure, preventing it from getting too high.

Will bleeding radiators reduce pressure?





Bleeding radiators

If you bled your radiators recently, you may have lost some pressure. That’s because, when you bleed a radiator, air is released, which lowers the pressure in your boiler system.

Is 2.5 bar too high for a boiler?

If the bar is hitting over 2.5 bars, then the pressure from the water in the system is too high, and anything below 1 bar is too low.

Does running hot water reduce boiler pressure?

Naturally, parts expand when they heat up. So, as your heating/hot water comes on, you’ll see the pressure slowly rise. However, there should be pressure release devices in your boiler that stop pressure rising too far. So, you should expect to see your boiler’s rise by less than 0.3 bar.

How do you know if your boiler is going to explode?



The signs your water heater is going to explode are leaking tank water, the faulty pressure relief valve, cloudy water, popping noise, and the lack of hot water.