Glowworm Cxi Dripping and G10 Seal

A friend of mine recently moved into a new house and asked me to look at his boiler as there was a couple of outstanding issues left by the previous owner. Before moving into the house he had been told by an engineer that inspected the heating system that the boiler required a new G10 burner door seal. He was also told by the previous owner that there was a regular drip, hence the bowl underneath.

Looking at the burner door I could see that the boiler had the earlier burner door seal fitted. The main seal looked to be ok, but there was signs of staining at the bottom of the burner door where the smaller seal is. I knew it was likely to be the earlier seal as the burner door was secured using the earlier nuts which are not of the Nyloc type. I removed the burner door and exchanged the earlier 'rubber' seal for the graphite one. The lower seal is still made of 'rubber'. I also filled in the label with the date and stuck this to the boiler so the seal should get replaced in five years time.

The dripping I immediately noticed was coming from the disconnnector. The disconnector valve is the fancy non-return valve they have fitted to the built-in filling loop. It is quite common for them to drip just after re-pressurising the system, and sometimes the dripping stops after a minute or two. Unfortunately  the disconnector had been dripping for an extended period and required replacement with part number 802600. This part comes with a new disconnector valve and an upgraded filling tap. The earlier taps were plastic internally and use to seize and break shut, whereas the new ones are brass internally.

Had the disconnector not been leaking it would have been cheaper, and quite easy on this installation to use a standard filling loop on the existing pipework. After installing the new filling loop I repressurised the heating system which due to the low local water pressure was a struggle to get to 1 bar. The disconnector dripped after filling for a short period which I expect is a consequence of the low water pressure and would consider fitting a standard filling loop on my next visit.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.