Water too Clean

[meow2222]

Hi

Got a central heating problem I'm a bit confused about. Top floor rad was full of air, bled it and the water ran completely clear & clean, just like tap water, and its a fairly old system that had good quality inhibitor in. I figure this means a leak in the primary circuit, but can see no sign of any leak anywhere. I can only think of one explanation... a holed HW exchanger. Would it be right to say this is the only possibility?

System: Standard vented header tank, old boiler, pumped primary, don't know what plan it is.

If the above is right, presumably the solution is either a new tank with exchanger, or adding an exchanger to the existing tank.

Regards, NT

[Roger Mills]

What are the relative levels of the water in the cold header tank for the HW system and the F&E tank for the primary circuit? If the cold header is higher, is the level in F&T tank rising, and getting near the overflow? [This is the usual symptom if you have a leak in the coil in the HW cylinder].

[John]

Solids in the water may have separated out and be in the downstairs radiators.

[John Stumbles]

I usually find the water from bleed valves is pretty clean. If it's noticeably dirty that indicates either a strirred-up system or a *very* dirty one.

[meow2222]

oh right, thanks :) Guess I've still got to figure out why the system's full of air though.

Lol

NT

[meow2222]

Good point. The F&E tank is a few feet above the HW header. Next time I get access I'll check them, then I'll know whats happening. Meanwhile the system styill works, just dont want to leave it to corrode away.

Thanks, NT

[Dave Plowman (News)]

Well I've just drained down mine to replace the rad in the bathroom with a towel rail - and that came out pretty clean. It was last drained about 5 years ago and new inhibitor added. The water left in the rad was blackish, though.

Sure the ball valve hasn't stuck?

I'd get it all working properly with no air in the rads then turn off the supply to the header tank - tie up the ball valve etc. Note the level in it. Then check it after a few weeks. A system in good condition can run for years on just the contents of the header tank.