flushing the heater core

So I'm going to flush the heater core. There are two hoses. One goes from the firewall to the front of the car and meets with a bigger hose that goes to the bottom of the radiator, another hose goes from the firewall into the back of the engine which then probably goes through the engine and to the thermostat to the top of the radiator. I'm told that placing a garden hose or something to pump water through will push any dirt or blockage. Which hose do I need to take off to hook up to a garden hose or something to pump water through? I'm not sure which way the coolant flows. If this is not the correct way to go about doing this then tell me.

hello,both hoses should come off.you can cut hoses at the core
then splice in a connector when done.usaully this can be done w/car off
w/low pressure put garden hose in/up to core & flush both ways
start with the out side of the heater core then in side, & so on
the hose going too the thermostat is the in line
of course they sell kits for doing this also

hello,both hoses should come off.you can cut hoses at the core
then splice in a connector when done.usaully this can be done w/car off
w/low pressure put garden hose in/up to core & flush both ways
start with the out side of the heater core then in side, & so on
the hose going too the thermostat is the in line
of course they sell kits for doing this also


And by the way often should flushing be done. My '08 Kia is still in her "mid-20s".

hello,both hoses should come off.you can cut hoses at the core
then splice in a connector when done.usaully this can be done w/car off
w/low pressure put garden hose in/up to core & flush both ways
start with the out side of the heater core then in side, & so on
the hose going too the thermostat is the in line
of course they sell kits for doing this also

Should I take the hose going to the bottom of the radiator off at the firewall or radiator? So the flow goes from the radiator, to the thermostat, through the engine, then the heater core, then back to the radiator? And I should flush it both ways. Correct? Anything else?

what car model year engine miles.....

Splice into the hose that goes to the bottom of the radiator. Ths will let you flush out all the rust and debris that has settled at the bottom of the radiator.

The small hose from the back of the engine is from the thermostat bypass that, as you correctly presumed, has flowed through the engine and into the heater core to help heat the interior faster. There is a tiny hole in the thermostat face to allow some flow from the pump, but not much until it opens.