Then resart it DS with immediate effect. I have had to replace two of these "new" bulbs this weekend. One in the entrance hall and one on the landing. Both were installed at the same time less than a year ago when we took the decision to "go green" in an attempt to reduce our electricity bill. The "new" bulbs were, I admit a free gift from British Gas (see posts passim) but they do not get a great deal of use, positioned as described. Had I paid for them I would have been mighty miffed. Meanwhile we await the other 10 bulbs, replaced with freebies at the same time, to fail also. It is worthy of note that my electricity bill has not reduced by a single penny ~ rather it has gone up.
Meanwhile the replacements give better light, making the stairs much safer, are 60 watt old fashioned types purchased yesterday from the local Spar Shop for 49pence each.