If your boiler's pump is bad, it will likely need to be replaced. There are a few ways to tell if your boiler's pump is failing or has failed.
First, you may notice that your boiler is making strange noises. These could be grinding, whirring, or clicking sounds coming from the pump itself.
Second, you may notice that your boiler is not heating up as quickly as it used to. This could be because the pump is not circulating hot water as efficiently as it once did.
Third, you may see leaks coming from the pump or around the base of the boiler unit. Water leaking from the pump is a sure sign that it needs to be replaced.
If you suspect that your boiler's pump is failing, it's best to call a qualified technician for an inspection and diagnosis. They can confirm whether or not the pump needs to be replaced and make the necessary repairs.