There are no national statutes that say you have to service your extinguishing systems. They are there to protect your business assets and are probably a requirement of your insurers (even though they may not have been put in for that reason). You may find that an insurance company may not honour a claim if they feel that a failure to service a system contributed to the loss.

Whether you believe you are obliged or not, you have a lot of capital invested in your Fire Extinguishing System. This would be wasted money if it didn't work. When you need the Fire Extinguishing System work it will be to save your property or your business so it must work properly. The only way you can be confident that it will work is if a professional company using properly trained and qualified engineers regularly services it. BS5306 requires the mechanical element of Fire Extinguishing Systems to be serviced at least twice per year and the electrical element four times.