Be suspicious of utility providers turning up unannounced at your door. Always ask for identification but check independently with the utility company. In most cases you will have received a letter in advance letting you know work will take place.
Trading Standards advice is to always say NO to cold callers. The Safetrader scheme can help you find a trader in your area, contact 0303 333 1111 or go to www.safetrader.org.u