Engine temp running 135......under 210 with heater on?

[Gossamer]

Changed out my thermostat because it was bad. Engine temp was over 235.
Now engine runs at normal temps (just under 210) only if the heater is on. If I turn heater off, the temp goes to about 230-235.
I have tried bleeding the air out several times. Parking on incline with cap off reservoir for several minutes.
Maybe I need to flush radiator?

 

[Doubeleive]

could be clogged, could be water pump fins worn down to just nub's also, how many miles???

 

[Gossamer]

could be clogged, could be water pump fins worn down to just nub's also, how many miles???

Water pump 1 year old.
Tahoe has 220,000

 

[Doubeleive]

Water pump 1 year old.
Tahoe has 220,000

if that is the original radiator you can put some chemicals in there and run it 2-3 days and flush it out and refill, the chemicals are sold at almost any auto parts store $5-10, that MIGHT help, but my personal recommendation would be to consider replacing it, if you shop around you can a decent replacement for about $180 unless you live in AK or somewhere exotic, rockauto probably has some good prices.