How To Top Pressure On a Boiler
How to top up pressure on my boiler?
If you notice that you suddenly have no running hot water, your radiators aren't warming up and that the pressure gauge has fallen, it may be a sign that your boiler pressure is low. Here`s what to do if this happens.
Top up boiler pressure.
Always check the manufacturer’s instructions.
The boiler pressure should be between 1 & 2. If the pressure on the boiler drops below 1 bar you will need to top the pressure up on the boiler.
Filling loops do come in a variety of designs but often they are underneath the boiler and look like a silver flexible braided hose. (A filling loop is a hose or a ridged section of pipe that connects your boiler to the mains water supply)
If your property is managed by us and you are unsure of which valves to turn to top the pressure up, please send a photo of the pipework underneath of your boiler and the pressure gauge via WhatsApp stating your property address. ( refer to welcome pack emergency number).
Once you have located the filling loop you should then see 2 x valves to either side of the filling loop. These should both be turned a 1/4 of a turn in line with the pipe, you will then hear water entering the system and see the pressure gauge starting to rise. When the pressure reaches 1.5 you can then turn both valves back off. Some boilers may have flat headed screw instead of the valves.
When the lever or screw is perpendicular to the pipe it’s usually turned off. It’s important to ensure both are turned off to avoid over pressurising the system.
Your radiators may then need bleeding to remove any air from the system. You can purchase a bleed key from the local hardware shop for around £1.00. Please see our guide on how to bleed a radiator for more information on how to do this.
Should pressure on cold system be 1 or 1.5?
When your heating is switched off, the ideal water pressure should be between 1 and 1.5.
Are they called valves/taps?
When dealing with boiler pressure, you may find that the valves, otherwise known as taps, are located at the bottom of the boiler.
If you are frequently topping up pressure on your boiler, then there could be a minor leak somewhere on the central heating system. A common place to check is around the TRV’s (Thermostatic Radiator Valves) on the radiators.