Hi everyone,

I had a plumber round a few weeks ago to fix an overflowing central
heating tank in the loft. I was in a hurry, so he just fitted an
isolating valve to the inlet and turned off the cold water supply. He
also removed some of the water from the tank, but said that the water
in the tank was very hot which shouldn't happen.

I've left the isolating valve switched off, but the pump has begun
making a lot of noise, so I went up in the loft, and the central
heating tank had run dry... I have now let more water into it.
However, before I fork out loads on a plumber, I have a couple of
questions:

1. Why is the water in the central heating tank getting so hot (there
was steam coming off it)
2. Why is the tank running dry so quickly... I would have thought
water loss from the system should be relatively low - but half the
tank has been emptied by it in 3 weeks.

What could the problem be and how much will it cost a professional to
fix it?

Any answers much appreciated.

Ian