"cynic" wrote in message
...
On Dec 27, 4:50 pm, TheOldFellow wrote:
Did all the right things. Left the (sealed system) heating on, turned
the water stopcock off, drained down the cold water system right to
the stop-cock.

After five days returned to no supply at the drain-down just 3 inches
above the stop-cock which is just 4 inches above the slab.

United Utilities says they are very busy, and they might call me back
in a few hours to take details. Sounds like a long wait.

So how can I move the thawing of the supply pipe forward? The
15mm black plastic incommer is gently curving as it enters the slab, so
pushing a thaw-pipe in is going to be hard. Is there any electrical
way - water does conduct a little?

I suspect, that like the electricity supply, it isn't buried far enough.
So I might be into trenching.....

I hate winter.

R.

Change your service pipe to lead then connect a small welder output
across the section from street stoptap to indoor stoptap just as we
had to do in 1964 when the problem was common all over the country.
This new fangled plastic pipe is no good for passing enough current to
create heat :-)

On the other hand ice is more resistive than water, so any current you can
pass into the stopcock will largely heat only the plugs of ice. Assuming
the plug of water the other side is earthed somehow! It might also be a
good idea to isolate the internal piping first.

Anther advantage of plastic pipes is that they are largely transparent to
microwaves, though the idea of a magnetron with it's power supply outdoors
is perhaps a little beyond DIY!!