No luck with thermostat

[Straight six]

Well I replaced the thermostat and no luck the top radiator hose stays cool the bottom one as well. The heat works really well I'm not sure if that has anything to do with anything. The radiator stays cool. The water neck gets very hot so I don't get why hose would be cool. New water pump in august

[Dead Parrot]

As a test, run it without the thermostat and make sure the radiator is completely full. Leave the radiator cap off. You should see a lot of flow in the radiator and everything should get somewhat warm. It may not get hot without the thermostat.

While the thermostat is out, put it in a pan of boiling water. It should open. It you have a meat thermometer, you can check the open temp.

[tlawre87]

To add:
Are you losing any coolant? You have a 250 which the heads can have a tendency crack.

Last...new or rebuilt water pump? Seems like anymore on the reman parts you're going to get a bad one occasionally. Any leaks around the weep holes?

[Straight six]

Yes it's a new water pump no leaks. Well I decided to take it for a ride drove fine got back home the top hose was hot again I don't understand. Well it's working for now...

[bnoon]

If you had an air bubble caught somewhere it may not have "burped" it free until you went for the drive. Sloshing around corners and varied RPM will work air bubbles free a lot of times. I'm glad the heater is working for you too, it's when the heater blows cold that you REALLY have to worry! Good luck with continued success!