A step-by-step guide on what should be your boiler’s pressure, is it too high or too low?
What is Boiler Pressure?
It means the pressure at which your heating system operates. The boiler uses a certain amount of pressure to heat the cold water that runs through your house and the radiators’ pipes. It should balance the pressure at an optimum rate, not too low and not too high otherwise, your boiler might lose the pressure or could completely shut down.
What Pressure Should My Boiler be?
While the pressure reading for every boiler varies with brand and functionality, the most common reading at which most heating systems operate is between 1-2 bar.
- The gauge’s needle should be between 1-1.5 when the heating system is switched off.
- The gauge’s needle should be between 1.5-2 when the heating system is switched on.
The pressure gauge on most boilers will highlight the optimum pressure level through a green area. The red area will notify you if your pressure is of concern.
How Often Should I Check My Boiler Pressure?
Your boiler system needs a balanced pressure to heat the water entering the system and keep you warm in the freezing temperature of winter. For that, you need to have a maintained check on the pressure, or otherwise, your heating system might break down if neglected for a long time, and no one would want to remain cold around chilly breezes. So, it is anticipated to always keep a check on your boiler’s pressure.
However, you do not need to check the boiler pressure daily. Check it once a month, after every boiler service, and radiator bleeding as the system mostly loses pressure after the repairs. Also, check it after the boiler top-ups as the system might get over-pressurized.
How Do I Check the Boiler Pressure?
You will find a pressure gauge on the fascia panel of your boiler. In modern combination boilers, you will see digital calculations with a flashing pressure reading if there is a warning of high or low pressure. In hydraulic gauges, you will see the needle in the red zone if there is a warning.
If you see the needle at the reading above 2.5 bar, your boiler pressure is too high. If the needle is below 1, your boiler pressure is too low.
What Do I Do If My Boiler Pressure Too High?
When your gauge reads above 2.5, then your heating systems need to be depressurized. When there is excess air trapped in the system, the pressure tends to rise.
Reasons and Remedies for Increased Pressure
1. Recently Topped Up Boiler
One cause of boiler pressure being too high could be that you recently got your boiler serviced after facing a pressure loss. The increase of water in the system leads to increased boiler pressure. For that, you need to excrete some water out of the system. You can do that by loosening the PRV (pressure release valve). It is a valve located outside of your house, mostly behind the boiler wall. This valve releases water when the system is under pressure. But you need to be careful while performing this step as the water could be hot.
2. Too Much Water in the System
When there is too much water flowing in the system and air, the boiler pressure rises. The air might get into the system if the fixing valve is not tightly closed or broken. In this situation, you can check for damages to the valve or tighten it if it loosens the valve. After going through the valve, you need to bleed one or more radiators (depending upon the bleeding need) to release air and some water for depressurizing the boiler.
What to Do If My Boiler Pressure Is Too Low?
If your boiler keeps losing pressure, then it needs to be topped up. There are three different ways to top up your heating system:
- Using an external filling loop
- Using a Keyed filling loop
- Using a Keyless filling loop
Note: All the steps mentioned above are easy to conduct, but the instructions might vary with boiler brands and structure; hence it is advised to go through your boiler’s company guide. Regardless, if your boiler keeps dropping pressure, and you still cannot figure out what is wrong, it will be suggested to take the help and assistance of a certified, gas-safe engineer.
External filling loop: This loop is located externally at the boiler’s bottom or side and works like a looped hose. You need to attach the filling loop to the designated valve, slightly unscrew the valve, or move the lever and observe the pressure gauge. When the reading comes to 1-1.5, close the valve, and disconnect the loop.
Keyed filling loop: It attaches the loop beneath the boiler on the right side. It needs a key to operate, which is in the removable panel at the boiler’s bottom. Plunge the filling key into the hole and tighten it until it shuts. Turn the close handle with the goal that water fills into the heating system. Do this until the pressure needle moves into the green zone. Turn the handle back to its position and eliminate the key.
Keyless filling loop: The loop is beneath the boiler, at the right side, and operates with a lever accessible through the removable panel down to the boiler. Move the filling lever until you hear water entering the system and wait till the pressure needle in the gauge moves to the green zone and pull the lever back to its place.
After filling up your central heating system, turn on the boiler and wait for the system to heat. Observe the pressure gauge and notice the needle does not move outside the green zone, for example, above 2.5, or it would mean that you have overfilled your system. For that, you would need to depressurize it by following the steps mentioned above of depressurizing until you reach the required pressure
Is Low Boiler Pressure Dangerous For Your Boiler?
Most people don’t realise how low pressure in a boiler can have severe effects on its durability, yet many are concerned whether low boiler pressure is threatening.
A boiler can lose pressure for various reasons. It can be because of a leak in the pressure relief valve, an issue in the expansion vessel, the air in the system, or a leak in the heating pipework.
What Should The Pressure Be On A Combi Boiler?
The pressure of your combi boiler should be between 1 and 1.5.
If your pressure is less than 1, you might have lost water from the system because of a leak.
If the pressure reads at 2.75 or above, you may need to bleed a radiator to release the pressure and bring it back to its suitable level.
If you bleed a radiator, make sure that you have a way of trapping the water to prevent the walls or floor from being wrecked. Take caution when undertaking this job as the water can be very hot.
If you’re unsure about anything, it’s a good idea to call an engineer who can help you. 24/7 Home Rescue has some of the best specialists around the UK, working around the clock day and night.
If you find a leak or suspect that you have one, call a plumber who will examine and fix the query. If you still feel the pressure has dropped increasingly over time, you can adjust the boiler pressure yourself.
Discover Error Codes For Boilers With High Pressure:
If the Pressure on Worcester Bosch boiler is too high:
E9, A1, 224V, 1065B, 2970B
Relevant to (Boiler Model):
Worcester Bosch Greenstar 25i, Worcester Bosch Greenstar 30i, Worcester Bosch CDi, Worcester Bosch CDi Classic, Worcester Bosch CDi Compact, Worcester Bosch CDi Highflow
If the Pressure on Vaillant boiler is too high:
F.12, F.74, F.75, S.41
Relevant to (Boiler Model):
Vaillant EcoTEC, Vaillant EcoTEC Pro, Vaillant EcoTEC Plus, Vaillant EcoMax, Vaillant ecoFIT
If Ideal’s boiler pressure is too high
F1 – Ideal boilers tend to commune in English and typically display written messages about pressure issues which are… Ideal.
Relevant to (Boiler Model):
Ideal Logic, Ideal Logic Plus, Ideal Vogue, Ideal Vogue Max, Ideal Mini, Ideal Isar.
Frequent Loss In Boiler Pressure?
If your boiler is still losing pressure frequently after topping it up, there could be some internal issues with your heating system. To detect the primary culprit, check for the following issue:
Leaks In The System:
The central heating system of a house requires a balanced pressure to work efficiently, and if there is any damage or leak in the internal structure, the boiler might not perform at its best. Check for the leaks in piping, boiler, or radiators in your house. Do not dive into the internal parts of the boilers, though. A Safe Gas engineer should only detect and repair the internal leaks.
Still, Having Trouble?
If your boiler is still making trouble, then you should not further tackle around your boiler pressure and immediately book a safe gas engineer to have a look and repair your system to avoid any unforeseen consequences.
If you are a 24/7 Home Rescue customer, you can reach us anytime on 0345 0774 177 to get immediate help over the call or book a professional repair appointment.
Our technical team will run through some simple troubleshooting to see if they can resolve your problem on the phone, or they can book one of their friendly and knowledgeable Gas Safe registered engineers. To get you back up and running as soon as possible.
You can always avail of our one-off repair service at a fixed rate if you are not a 24/7 Home Rescue customer.