ESPAR DIESEL FORCED AIR HEATER

[Tantramar]

I have an Espar diesel forced air heater on my boat. I don't use it a lot but this year when I tested it - no go. I diagnosed the problem as a faulty fuel pump. The power to the pump was good but no pumping. I bought a new fuel pump. Still no pumping. I bought another fuel pump. Again, no pumping. I tested the fuel pump(s) and they seem to make one click and deliver a bit of a squirt then nothing. By disconnecting the power and re-connecting the power supply the pump sort of works. It appears that every time there is a pulse of current the pump clicks and delivers.
Is this normal and is there something on the control board that delivers a pulse of current instead of just being "on"? There is always current at the connection point with the fuel pump.
Is it possible that I have yet another faulty fuel pump?
Hope someone can offer a solution.
Thanks.

[Windpilot]

They just pulse, I have a Chinese knock off for the last 4 years and did my own investigation as to how they work. They're pretty much the same.
But, the pulse pumps should start and keep going, slow at startup, faster at fully on max.