Electric Pond Heaters
Although not the cheapest to run, the in line Electric Pond Heaters are the cheapest and possibly the easiest form of heating to install. A good quality heater can be obtained for less than £200. They are physically small, and are easy to retrofit into an existing installation since they can be fitted by cutting into a straight length of pipe work, but not just any piece of pipe work will do. Installation is simple but there are some basic rules that should be followed.
The elements in an electric heater are intended to be permanently immersed in water whilst they are heating and will quickly burn out if the water flow through the heater doesn’t fully cover them when they are switched on. Good quality heaters usually include a flow switch which will switch them off if the water flow stops.