Wheel filling loop

Before you start

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

You should be able to see the 2 black wheels towards the front right-hand side underneath your boiler.

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.

Using the Wheel type filling loop (found on Baxi Duo-Tec 28 he a). The pressure should be 1.5 bar when the system is cool.

Let’s give it a go!

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

Turning the right-hand wheel towards you will open it, and away from you will close it. Turning the left-hand wheel away from you will open it and towards you will close it. You must always keep an eye on the pressure gauge as you top up the pressure.

Turn one wheel anti-clockwise about 6 turns, then slowly turn the other wheel anti-clockwise until you hear water start to flow into the boiler. Keep your hand on this wheel until the pressure gauge has reached 1.5 bar then turn the wheel fully in the opposite direction (clockwise). Now turn off the other wheel fully.

When you have topped up the pressure, double check that you have turned both wheels off.

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.