Surge protection for a boiler

I am experiencing problems with the Control Unit on our Worcester-Bosch boiler. Three have failed in 18 months and the heating engineer is baffled. The only thing he can think of is that the unit is susceptible to current surges. Any ideas on how to incorporate anti surge protection into the circuit? These units are around £45 each plus the cost of the engineers time so it is becoming expensive.

Plug in surge protectors are available in all the Brico's and many of the larger supermarkets, usually in the TV/ PC areas. They do not cost a great deal. This is one example: http://www.ebay.fr/itm/Prise-Anti-Surtension-et-Parafoudre-Pour-Tout-Appareil-Telephonique-/311341545794?pt=LH_DefaultDomain_71&hash=item487d66f942 The example shown is principally for protecting 'phone lines and networks, therefore you must make sure that any S/protector that you buy covers the main A/C outlet also.

Le Dolly - Thanks for the information. Now I know what to buy.