Refilling A Heating System With a Filling Key

Heating systems can be a little bit of a nightmare to deal with at times – they can break down at the slightest bit of notice and leave you with a real problem on your hands. Especially in the winter months, the last thing you want is a damaged repair system – jackets are supposed to be worn outside, not in!

So, if you are having problems with your heater then the solution may lie in using an internal filing key to correct the issue. If this is the case and you need to create a solution using your key, then the best way to do it is yourself. Of course, if you can’t follow this tutorial or find it too confusing we’ll be more than happy to help out and do the job for you. Just give us a call for more help and we can prepare the job for you. Otherwise, this tutorial should help you piece everything together quickly & effectively.

They All Need Toping Up

Typically, all system & combination boilers will require a top-up to the system pressure at some point in their lifespan.  This is done using cold water. You will usually be able to notice the signs of a weakened or poorly functioning boiler by a noticeable lack of heating efficiency. if you want to know exactly how much you have, then you can check the gauge on the front of your boilers control unit. This will give you a little reticle just like you would expect to see on a car dashboard, showing you how much you have.

If the needle is sitting in the red rather than the green zones, you may need more or less water to be added. Depending on what you use, you have two typical options to follow. Today, we will be concentrating on the internal filling key solution. The other option would have been to use the external equivalent, but most boilers use the internal filling key.

First off, you need to turn off the power to the boiler and remove the bottom section of the boiler so that you can locate the key. There is a small, black, plastic hole that your key will fit into and you need to stick the key in here. This will actually link your cold mains into the boiler itself. If you look closely you will see a small open and closed lock symbol on the manifold you need to fit the key into. You want to place the key so that it the arrow on the key is pointing towards the open lock symbol.

Now, you turn the key to the closed lock position and turn the small white plastic nut anti-clockwise that will be next to your key. You will literally hear the water flowing into the system. Keep an eye on your pressure gauge and you will see it moving up quite rapidly. As you hit the required amount, turn the key until you hear the water stopping and not flowing in any longer.

Now, turn the key to face the open lock position once again, and get something to clean up any excess water that comes out. If continual water keeps coming out you might need to tighten the little bolt up a little more. Remove the key, and put the key back in its slot. Fit the bottom back onto the boiler and you should be good to go!

Got any questions? Ask us – we’ll be more than happy to help.