Could gunk in expansion tank cause damage to central heating?
All aspects of plumbing questions and answers, help, tips and information

2 posts   •   Page 1 of 1
dpw_
Labourer
Labourer
Posts: 1
Joined: Sun Oct 11, 2020 8:10 pm

Could gunk in expansion tank cause damage to central heating?

by dpw_ » Sun Oct 11, 2020 8:22 pm

Hi - DIY plumber looking for advice.

We have what I think is a Y-plan system, where a single boiler heats the hot water tank and the radiators.

This morning I fitted a new radiator. simple enough, no leaks yet...

Tonight I noticed the CH and water pump was making a terrible noise, and the rads were cold despite the stat demanding heat. I tapped the pipes around the pump, and they sounded empty, and the bleed valve by the hot water tank was not pressurised when I checked there.

I guess that filling the new radiator caused a massive airlock, although where the air came from I have no idea.

The expansion tank in the loft was full of black water, with lots of big globs of gunk. Really gross, like a fish tank overgrown with pond weed.

Despite the gagging, I emptied the expansion tank via a bucket and down the loo, and when I could access the pipe feeding the system, I gave it a 'good fingering' as a make shift plunger. This seemed to release a blockage in the pipework below (judging by the gurgling). I then cleaned the tank and refilled.

The system seems to be working now but I am worried that I have a glob of gunk in the system which will cause an issue down the line.

Do I need to do anything?

Over time we intend to replace a number of rads, I will be cleaning out the expansion tank first next time

Thanks for any advice.

Dan

stoneyboy
Project Manager
Project Manager
Posts: 6432
Joined: Wed Dec 10, 2008 6:44 pm

Re: Could gunk in expansion tank cause damage to central heating?

by stoneyboy » Tue Oct 13, 2020 10:52 pm

Hi dpw_
Suggest you should flush the system, fit a filter (magnatec or something similar) and add system preservative when refilling.
Regards S

2 posts   •   Page 1 of 1
It is currently Sat Apr 27, 2024 2:17 am