 Investment Cost
Electric boilers are a little cheaper than air source heat pumps (ASHPs), but they consume about three to four times more electricity. Hence the running cost is very less when compared to electric heater making it an economical solution overall.

 Energy Conservation
The operation of air source heat pumps is a process of heat generation via the absorption of the energy in the air and the compression of compressor, which is about 4 times more energy-saving than traditional electric boiler; while electric boiler is a device of direct heat generation without any energy conversion, so only 90% heat can be generated. Thus, ASHPs are more energy-saving than electric boilers.
1. Air to water heat pumps can realize the process of 1KW being converted into 4KW all year round.
2. Boilers can only realize the process of turning 1KW into 0.95KW or lower.

Hence, electric heaters deplete the energy reserve at a faster rate which is not the case with heat pumps.
So, If you want to save energy and be environmentally responsible, undoubtedly your choice has to be heat pumps.

 Operating Principle
The operation principle of ASHP is based on the principle of the reverse Carnot cycle and is refrigerant based similar to a refrigerator. Majorly, it consists of the evaporator, compressor, condenser and expansion valve.

Electric water Heaters are composed of electric heater and related electric control components. They are mainly in the form of electric heating and output steam, high-temperature water or organic heat carrier with certain heat energy.

 Safety
There is no pressure or leakage danger in the process of heat generation of ASHP. During the heat generation process of an electric boiler, the insulated shell shall be checked to see whether there is the possibility of electric leakage and the risk of electric shock.

 Requirements for Electric Power
The electric load of air source heat pumps is 1/3 or 1/4 smaller than that of electric boilers, and the requirement of power grid is smaller than that of traditional electric furnaces.

 Functionality
ASHP belongs to a type of HVAC equipment. It can achieve heating, cooling and hot water for daily life according to the needs of users, with three functions available in one unit. The function of electric boiler is relatively simple, only to achieve the water heating function.