Water pump doesn`t turn on - sometimes

pancake12

Hi All, Can someone help please. When I open the hot water tap in the kitchen and in the bathroom, 70% of the time the water pump does not start. But sometimes everything is fine. This issue is only with the hot water. I also noticed that whenever it doesnt want to start, I open the cold water tap in the bathrom (which also uses the pump), and then it does start. So let`s say - in the kitchen the hot water doesnt start the pump - I open the cold water tap in the bathroom - that starts the pump, and then the water is also good in the kitchen. I hope this makes sense. Why do you think this keeps happening in the last 2 weeks.

John.G

What is the pump make & model?