Combi boiler issues

Conway0108

This is my first post but any help would be much appreciated:

Myself and my girlfriend moved into our first home last week, which is a 15 year old end terraced house. Over the weekend, I decided to just check the boiler pressure, and immediately noticed it was high (around 3). It had been serviced about a month ago which we had the certificate for, so I didn't think there would be an issue. As it is a combi, I managed to find the pressure release valve, which I used to get the pressure down to just below 1.5, which it stayed at for a while. However, over the next 24 hours, it has gradually crept up again until it is nearly 2.5 now again, which is worrying me. The heating has been off the whole time (minus when we checked it was working), so it can't be that.

When I used the release valve, a lot of water came through the outlet pipe at the back of the boiler outside, but it also still seems to be dripping out that pipe again now the pressure has risen.

We have had no issues with hot water, and when I checked the heating, all the radiators heated up quickly and evenly. Although I haven't tried bleeding any radiators yet.

The other issue is, when we use any hot water, or turn the heating on, the boiler immediately makes a bit of a whirring noise. It isn't loud or rattling, but I just wanted to make sure that was normal too?

I am basically trying to find out what the problem could be, and what may need doing/changing. The boiler is as old as the house, so is around 15 years old, so it may be just age. But like I say the heating is fine as is the hot water, and it always comes in very quickly. Does anybody know what it could be or has anyone had a similar issue with a combi? The boiler is Bax but I'm not sure on the model.

Any help would be great?!

Thanks

Josh

macman

Almost certainly caused by the filling loop not closed (or not closing) properly, so it's constantly filling and over-pressurising-it should be around 1 bar only. Check the valves at each end of the loop.
A very simple and cheap part to change.
You may also need to get the PRV changed as well, since once lifted, they often won't reseat fully.