Generally speaking there are two different types of lead acid battery, Starting and Deep Cycle. If a starting battery is routinely deep cycled (discharged below 20%-50% of max capacity) it will generally fail after 30-150 cycles. The same starting battery will last for thousands of cycles if it is just used normally (2% - 5% discharge).
These phosphates precipitate the solids to the bottom of the boiler drum. At the bottom of the boiler drum there is a bottom blow to remove these solids. These chemicals also include anti-scaling agents, oxygen scavengers, and anti-foaming agents.
Different types of boilers and boiler brands. The boiler market in the UK is dominated by one particular type of boiler: the condensing boiler. However, there are different types of condensing boiler, including combi-boilers, heat-only and system boilers. Popular brands producing combi-boilers include Baxi and Glow Worm (both Baxi heating boilers and Glow Worm boilers are British made).