Cold water tank emptying

[HERTS P&D]

I would also try: turn off the water supply to the CWST, turn the mains back on and see what doesn't fill/work.

Andy

 

[pmbpmb]

Hi CBW, I'm right with you, but unfortunately that gate valve is fooked.

Have called someone about getting it replaced.

 

[pmbpmb]

I would also try: turn off the water supply to the CWST, turn the mains back on and see what doesn't fill/work.

Andy

Hi Andy, thank you. Wouldn't the tank have to be fully empty first?

 

[lostinthelight]

I would have the gate valve replaced with a lever ball valve, the valves are seldom used and when needed, gate valves are mostly inoperable.

 

[pmbpmb]

I would have the gate valve replaced with a lever ball valve, the valves are seldom used and when needed, gate valves are mostly inoperable.

Agreed! I always turn these things with a great deal of trepidation

 

[terryplumb]

You have a leak , probably on a hot water branch .fit a bung in the loft tanks outlet that feeds the hot water cylinder. See if loft tank water level stops falling .
As you can't see any visible signs of leakage it's highly likely the leaking pipe is buried in concrete.

 

[pmbpmb]

Hi terryplumb,

Thanks for the message.

Yeah, it's looking like it. Just put the water back on and re-measured, looks like the tank lost roughly 39 litres over 7h 20mins.
If my maths is right, that's 5 litres an hour or 120 litres a day or 3720 litres a month. You'd expect to see that amount of water appearing somewhere, but there's literally no sign of it (except on the meter).

Funnily enough, the wife's put her ear to the taps in the downstairs toilet and could hear a noise. She's got better hearing than me, but there's a definite sound of moving water - like a cistern filling (even though none are). Guess that might narrow it down a bit further?

Out of interest, have you seen (or dealt with) many leaks in concrete?

Off to check the insurance now... And look for a reliable leak finding person/firm.

Cheers,

pmb

 

[terryplumb]

Lost count of the amount of times that I have seen copper pipes that have leaked buried in concrete.

 

[pmbpmb]

Lost count of the amount of times that I have seen copper pipes that have leaked buried in concrete.

 

[pmbpmb]

Just to complete the thread.
Got the insurers in for trace and access.
Slow leak found under kitchen sink, next to outside wall.
Gonna need to pull out the unit under the sink and pull up floorboards - but at least it's not pulling up laminate and hacking into concrete.
Thanks for responses.

 

[HERTS P&D]

How did they pin point where the leak was?

Andy

 

[AdrianUK]

How did they pin point where the leak was?

Andy

Have a look at 'ADILeakDetectiveMG' on You Tube. Some quiet smart methods used to find hidden leaks!

 

[HERTS P&D]

Yes, I know, I want to know how or what they done.

Andy

 

[lostinthelight]

My laser measure has an inbuilt inclinometer so can work out vertical height from the angle but I've not used that function.

 

[pmbpmb]

Water meter still turning. Guys came back and found *another* leak, this time in concrete.

Had to gas system this time.

Process was:
1. Cold water feed to cylinder turned off. Cut through feed pipe (to keep gas out of it). Cap off.
2. Cap off overflow to cold water tank in loft.
3. Drain HW taps.
4. Detach a ground floor HW pipe from tap.
5. Attach hydrogen/nitrogen mix cylinder to HW pipe. Apply gas.
6. Use detectors to get approx location of leak.
7. Gas off, start digging.
8. Put gas occasionally on to hear the leak as you get closer.
9. Chuck water over leak with gas on to identify exact location.
10. Fix leak.
11. Take caps off. Reattach HW tap and immersion.
12. Water on, check fix.
13. Check meter.

On summary:
- I only have respect for these guys as they spent hours+hours on their hands and knees hacking through floors.
- Glad this is an insurance job as that's 3 floors knackered.

Over + out.