Had a similar fault once with copper pipes (heating/hot water) buried in concrete floor, pipes had fractured and allowed the c/w cistern to fill the f/e tank!
Corgiman.... That sounds like a sensible thing to do. I assume that if the coil is holed that the water in the F&E tank would disappear into the system as it would leak into the HW cyl.
Wife thinks you are in fact corgiwoman as that idea is so sensible.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local