Unable to increase pressure of BG 330+ boiler (Gloworm)

[bigglesuk]

I've got a sealed system in my house with a British Gas 330+ boiler (re-badged Glow-worm). Currently the boiler is reporting that the pressure is 0.3 bar but is still working. When attempting to increase the pressure using the filling loop a small amount of water enters the system for a few seconds and then stops and the pressure stays the same.

I've changed the isolater valve on the return pipe that the filling loop connects to, but that made no difference. The pressure in the system when changing that was more like 0.3 bar and not 1 bar as I didn't drain the system to do it, so the boiler seems to be reporting the correct pressure.

Any ideas what else may be stopping the pressure from increasing? It's not like the water is still flowing and any PRV's are letting water out, the water just stops flowing in.

There is a single radiator near the front door that isn't working, inlet pipe doesn't seem to have any water, so may have a blockage somewhere. If the heating is working in general that shouldn't stop the system from pressurising and more water flowing in?

Thanks in advance,

Adam

 

[footprints]

Does the pressure rise when the system is in use?
If not the gauge might be faulty.

 

[bigglesuk]

The pressure didn't increase, I tried a new sensor but then pressure went down to 0.0 bar. I then realised that no pressure was in the section that had the pressure sensor and the expansion vessel. So I removed the connector from the internal boiler drain valve (where it connects) and no water was coming out. The hole had become blocked, and after using a tool to push through the accumulated rubbish water flowed out.

I have a feeling that internally there is a lot of rubbish in the pipes/radiators, when I cleaned the Magnaclean the other month it had loads of debris in it on the magnet. A couple of the drain points don't work, whilst a couple of the radiators only warm slightly no matter. Also, one radiator doesn't work at all and another has cold spots. I think I need to get the system power flushed.

We only moved in back in June, and I don't think that the previous owners maintained a lot of things that well. Noticed a lot of maintenance issues once we moved in.

 

[footprints]

Sounds like the connection to the gauge might be blocked too, really not DIY to start dismantling the boiler. Call a Gas safe registered engineer. Sounds like you have inherited a rotten system, strange as a magnaclean should have trapped it but my guess is the system was sludged up before and the magnaclean fitted to try and overcome it.
I usually do not suggest powerflushing (it ain't cheap) but in this case I suggest you need an engineer to do so, he may also need to dismantle the boiler if the connecting tubes have s**t in them.
Rotten luck but you need to bite the bullet and get the system cleaned by a professional engineer and sorted or you will have constant problems.
If you are stuck for an engineer I would suggest British Gas they are often slagged off for selling powerflushes that are not needed but you certainly do need one and if the problem continues they will be there to return and sort it out, unlike a chap with a powerflush and an ad in yellow pages.