Knowing which furnace accessories to buy for a new boiler is a case of doing research and finding out the features and requirements of each system. Each boiler will require devices for loading and maintaining the fire, whether this is simply tongs and a watchful eye or shovels, rakes and special protective clothing.
Possibly the most important accessory and definitely the most valuable furnace accessory for its money will be a carbon monoxide alarm to be placed above the system. These alarms monitor the level of emissions coming from the unit and sound if there is anything detected above the normal levels. This is incredibly important for a furnace owner as carbon monoxide does not have an odor and often strikes in the night when the victim sleeps. There is also the problem that carbon monoxide poisoning symptoms are slow to develop, and may be confused for the flu or simple headaches. Anyone planning on buying a new furnace needs to make it a priority to buy at least one alarm, spare batteries and possibly even an indicator as a backup.
There are other, less vital but still important accessories that can be purchased. Units that have two pipes and would usually require holes drilling through the wall or ceiling can be fitted with concentric vent units to minimize the damage done to the area. Some units will also need to be lifted off the floor to meet safety requirements, be fitted with dampness protection or even adapted with high altitude kits so that they will still perform exactly as described at heights above 6,500 feet.