Coolant hose

First make sure the hose is in good condition. Then check the neck on the radiator where the hose attaches. Make sure the nipple isn't rounded off or the neck is cracked in any way.

Next check the condition of the hose clamp and that when it is clamped that the clamp is behind the nipple. If you're using the factor spring clamp, change it over to a worm/band type clamp.

Make sure the neck is bad first. Sometimes there'll be corrosion around it that can be sanded with sand paper. But if the neck is bad, then the radiator has to be replaced.

When you say no heat, is the blower blowing? If it is, but the air doesn't get hot, make sure they bled all the air out of the cooling system when the changed the radiator. Because air gets trapped in the heater core and won't let coolant flow through.

The easiest way to do this: While engine is cold

Remove the radiator cap that's located on top of the overflow container. Start the engine and turn heat on high and let the engine warm up to operating temps. When the radiator fans come on and/or both the upper and lower radiator hoses are hot to the touch, squeeze the upper radiator hose several times while watching for bubbles in the overflow tank. You may want to use gloves to squeeze the hose, and make sure the temp gauge doesn't go over the half way mark. If it does, shut the engine off.

Repeat this until there's no more bubbles in the system. Next check both the smaller hoses coming out of the firewall (heater core). They should both be hot. If you're sure you got all the air out of the system, then the heater control valve isn't working. That will be next.

According to AllData, you may not have a heater control valve like most systems. Coolant circulates through the core at all times. So there's still no heat after bleeding air and both hoses are hot, then I'd suspect a stuck blend door. That would be located inside the HVAC unit.

No problem