Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
Actually, if the system is not building up the proper pressure, the coolant can't circulate the way it should and that can have an adverse effect on the heating system. You will want to stop the water pump leak, (replace it) and make sure that the radiator cap is holding pressure, (15psi)
Try this method to bleed air from the cooling system:
Hopefully this will help!
Thanks. Reply back here with any new info.
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