Lever filling loop

Before you start

The heating should be turned off and should preferably be cool.

You should be able to see the levers towards the front right-hand side underneath your boiler.

The Lever type filling loop can be found on various boilers including Baxi Duo-Tec 28 ga 2 and Potterton Assure or Ultra combi.

You should be able to find the levers on the underside of your boiler on the right-hand side towards the front. The levers are likely to be blue or black and will be connected to a metal tube in between them. The gas isolation point is sometimes a yellow lever, and the filling loop is slightly more forward and to the right of this.

Do not to turn any valves or levers to the back of the boiler, as these are the boilers primary flow and return pipes, gas supply and hot and cold-water inlets and outlets. Before you attempt to top up the boiler it's a good idea to try to turn each valve on and off, one at a time, so you are familiar with the process before you start.

Let’s give it a go!

Here's a handy video you can watch on how to top up your pressure.



Turn both lever valves a quarter turn, so they are parallel with the pipe they are connected to. If they are diagonal to the pipe they are closed. They will usually only turn one way, and one will be stiffer than the other. Try turning the stiff tap first, then slowly open the other. Keep an eye on the pressure gauge as you do this.

If you struggle to turn one of the valves, try gripping it with both hands if you can. You should hear water running into the boiler. Keep one hand on one of the valves ready to turn it off when the gauge reaches 1.5 bar as you don't want to put too much pressure in.

When you’ve topped up the pressure just double check both the levers are in the diagonal position, and they are closed.

If you find that you’re regularly having to top up your system pressure (e.g., more than once every 2 or 3 months) it suggests there may be a leak somewhere on the heating system. There could also be an issue with your boiler. Please check all radiators, pipework, and valves to see if you can identify any leaks that may be causing this problem.