What Are The Symptoms Of A Failing CH Pump?

[CareerChangeChancer]

Haven't come across one, but I'm sure I will soon. What symptoms would you expect if a pump was failing on a vented type system? Also, what would be the symptoms of a pump that had stopped working completely?

Many thanks.
CCC

 

[tomy]

loss of heating and hot water on a fully pumped system with the boiler coming on and overheating quickly or lots of cycling

 

[m1key00]

If the pump is not working at all it bangs the system bangs and crashes like someone is hitting the pipes with a hammer.