Leaks and draughts are a guaranteed way of increasing your heating bills. You might as well throw your money on the woodburner! But, the good news is that it's relatively easy to block the worst ones up, and now, with a new gadget it's very easy to find where the worst ones are.

I don't usually review products, but when Black & Decker offered me the opportunity to try the new thermal leak detector, I leapt at it. It's really easy to use, and you can choose the level of sensitivity you want to measure.

First you take a reference reading. I did this on internal walls. Then you set the difference you're looking for. This could be 0.5, 3 or 5.5 degrees C. I plumped for 3C. If the difference in temperature between the reference reading and what you're pointing the leak detector at is less than 3C, the light stays green. If it's more than 3C colder, the light goes blue. More than 3C hotter, and it turns red. Couldn't be simpler.

What I liked most about it, is that it showed me what are the priorities for action. I hadn't realised how leaky the back door is, and I had thought that a couple of holes in the floor boards in the living room were worse in terms of heat loss than they actually are (though they're still worth tackling!). I was interested to find differences in temperature of the same outside wall, just by moving the detector a foot or so along. Does this mean the cavity wall isn't evenly packed in?

There were nice surprises too. The metal venetian blinds that I thought assumed would be hopeless insulators are doing a good job of keeping the heat in. It will be even better if I clear the window cill of clutter, so we can close them properly each night. I confirmed that curtains are good news for heat retention. 

All in all it was satisfying to find that our house is not too bad in terms of draughts. I had much more fun at my parents house, which is much older, with cold air from single glazed windows leaking into the room above the curtains and some howling draughts under doors.

The Black & Decker thermal leak detector is available for £49.99 from B&Q. I think it's definitely worth having. It makes it really easy to see which are the priority areas to highlight and help keep your bills down.

If you have a question about anything in the above blog, please ask it in the comments section below.