Plumbing - Overflow drips

smcqis

I noticed earlier than one of the 2 overflow pipes was dripping. What does this mean? Likely new ballcock needed? Any advice appreciated 

London50

Check the cistern, if you have valve with a brass arm bend it down so the water level stays below the overflow outlet. Check the float to see if it is spilt if so replace. other thing to check if my advise has not solved the problem is turn off the water and check the valve washer as it may have perished  if  so replace it

Hasbeen

Ballcock diaphragm washer requires changing easy job, if you can dissemble and get a new one the same.

Ballcock replacement a bit harder, but last resort if no new washer.

Jonesya

Find out which tank it is coming from.

Most likely is that it's just a fault with ball-!!!!!!, either poorly adjusted and needs the ball adjusting to lower the level, or if it's not been a problem previously, that the valve needs repairing or replacing. The rubber valves can go stiff, wear or foul so they don't seal fully when closed, allowing a drip or dribble which if you're not using much water will eventually overflow. You can get replacement rubber diaphragms and service the valve, although they can sieze up making if easier to replace the whole valve.

One other possibility, rarer, is a leak on the hot-water tank heat exchanger, letting the hot water leak into boiler circuit raising the level in the header tank (which is typically a smaller tank with a lower water level) causing it to over-flow.

smcqis

Seems to get worse when the heating is on

grumbler

It's the small expansion tank then.

Alfrescodave

You need to get up in the roof/loft and check the water levels in the tanks -one of them is obviously overflowing due to problems identified in previous posts. My money is on perished washer which is easily fixed.