How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Plumberpro Your Own Question
Plumberpro, Plumber
Category: Plumbing
Satisfied Customers: 634
Experience:  Heating and plumbing answers. 20 years experience
Type Your Plumbing Question Here...
Plumberpro is online now

I live in a large 3 bed detached house built in 1985,

This answer was rated:

I live in a large 3 bed detached house built in 1985, We have a conventional water system with a 40 gall tank in the attic, that tank is extremely well insulated with even rock wool on the lid. There are two toilets and two showers downstairs that are gravity fed from this tank. The heating is also conventional with a small tank next to the big cold tank - the small tank never looses any water. The problem we now have is we go away a lot and leave the house empty with the stop cock off. If we're away for over 3 wks the cold tank is empty approx 30 gals, the toilet cysterns are still full. I have even tried isolating the toilets when we go away. Because the tank has emptied we are then left with airlock in the pipes which I have to clear with a hosepipe into the cold tank outlet. i have crawled under the suspended ground floor and all the sub floor seems to be powder dry. If the leak was in the attic or on the first floor then the water would obviously show on the walls and ceilings. I have had a very experienced plumber out and we are mystified. Could this loss of water be caused by evaporation from the cold tank? Thank you , L.Jones
Hi , its a strange one if you haven't noticed any leaks. Do you have any dripping taps? The thing I would try first is adding gate valves to the tank outlets as close to the tank as possible and turning these offwhen away for a period , you will be closer to solving it. I wouldn't think that much could have evaporated especially if you have a lid. Have you checked the base of the tank for leaks.
Plumberpro and other Plumbing Specialists are ready to help you