If your car’s heater no seem to be working also well, it could be time to flush it out. Flushing out the pipe in the heater core will enable the coolant to flow more easily so there will always be warmth coolant to warm up the...

You are watching: Which hose is the inlet to the heater core


Step 1: Screw ~ above the adapter and also attach the brief section that tubing. This is to be attached come the outlet of the heater main point so you can reverse the direction of flow to loosen any type of sediment.


Step 2: situate heater core hoses. Look for 2 fairly thick hoses that operation straight right into the firewall.

The firewall is the metal wall between the internal of the vehicle and also the engine compartment. The pipe are typically on the passenger’s side together this is generally where the heater main point is situated inside the dash.


Step 3: identify inlet and outlet hoses come heater core. The inlet water tap may have a heater manage valve i m sorry regulates the amount of coolant flowing right into the heater core.

The outlet hose will commonly run right to the radiator or cooling system reservoir come return the coolant ~ flowing through the heater core.

Tip: If you are having actually trouble figuring the end which is which, as soon as the engine is hot, rotate the warm up every the way. The inlet hose will certainly be warmer together it is feeding warm coolant right into the heater main point which climate warms the air up going into the cabin.

Step 4: Make certain the engine is cold. Make certain the engine has actually sat for a couple of hours so the coolant isn’t also hot.

Opening up the cooling device while the coolant is still warm is really dangerous as it deserve to start boiling and steaming.

Part 2 the 3: removed the hoses

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Step 1: use pliers and pull the steel hose clamps back. Traction them ago a couple of inches so the we deserve to remove the hoses.

Tip: If the clamps are hard to pull back you can spray a tiny silicone lubricant to assist them move.


Step 2: remove heater core outlet hose. Slowly twist the hose back and soon while pulling to on slide it off the outlet.

Take treatment not to damages outlet port or you will need to replace the entirety heater core. If the hose is old and caked top top the outlet port, girlfriend may have to replace the hose as removing it will likely damage the seal.

Liquid will most most likely come out as well so have the rags all set to clean up any kind of spilled coolant.


Step 3: attach garden water tap to outlet. Through our adapter and tubing we’ll be able to pump new water directly into the heater main point to wash it out.

Get the tubing around an customs or therefore on the outlet to make a nice watertight seal.


Step 4: eliminate heater core inlet hose. Exact same as the outlet hose, tenderness twist and pull the water tap off.

Be ready for some more coolant coming out.


Step 5: attach the much longer section the tubing come heater main point inlet. Have actually the other end in the bucket to collection the coolant and also sediment that comes the end of the heater core.

Warning: store an eye ~ above the bucket as soon as there is coolant in the so it does no overflow. Never dump coolant or any type of automotive liquid down the drain. Constantly dispose of her old fluids the appropriate way. These chemicals room not friendly to the environment.

Part 3 of 4: Flushing out the heater core

Step 1: turn on the water. Don’t rotate the water on every the way; usually a 4 minutes 1 to half of a rotate from totally closed is enough.

Most heater cores have the right to only handle about 10 psi of push whereas the usual garden hose have the right to supply around 40 psi. Turning the flow up also high deserve to rupture the heater core and also then you’ll must replace the entirety unit.


Step 2: save flushing until the water coming the end is clear. As soon as the water coming the end of the heater main point is clear favor the water going in, the heater core has actually been flushed.

It shouldn’t take too long as over there isn’t much volume inside the heater core. If the circulation coming out is restricted, over there is likely a clog somewhere in the line and you’ll need to take a few extra procedures to acquire it out.

Step 3: switch the hoses and flush. Set up the garden hose to pump right into the inlet of the heater core and have the drain pipe on the outlet.

Since you just reversed the flow with the very first flush, you’ll walk to continual flow direction to shot and loosen up the sediment. Revolve on the water and also flush the device like before. If the flow is good after this relocate onto the following part, otherwise shot the next step.

Step 4: move the hoses and flush again. We’ll perform one much more reverse direction flush to try and eliminate the sediment.

If 3 flushes with water doesn’t resolve the clog, climate you’ll have to use part radiator cleaner.

Step 5: Unplug the garden hose and also adapter native the short piece of tubing. Leaving the clear tube attached to the heater core and pour in some radiator cleaner.

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Let the sit for 30 minutes.

Note: Make certain the cleaner you room using is good for aluminum and automotive use. Family chemicals can damages the heater core and also eat away at the aluminum.

Step 6: rinse the radiator cleaner out with water. Operation the water v the heater core to thoroughly rinse out the radiator cleaner.

Part 4 of 4: putting everything ago together

Materials Needed

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Step 1: Disconnect clean tubes from heater core. You deserve to leave the water inside the heater core.

It’s not enough to significantly impact the 50/50 mix that anti-freeze and also water inside the cooling system.

Note: If you have actually some 50/50 mix lying around, you can include it with the clear tubes still attached to fill the heater core through fresh coolant. It no really crucial to to buy a whole new jug just to execute this though.


Step 2: Reconnect the heater main point hoses. Make certain to download them the correct way, since having castle reversed can reason the heater come not function properly .


Step 3: move the water tap clamps earlier into place. Use the pliers again and also resecure the clamps over the inlet and also outlet come seal them.

Step 4: do sure any spilled anti-freeze has been cleaned up. Inspect the journey belts to make sure they nothing have any kind of water or anti-freeze as this can cause the belt come slip.

Step 5: start the engine and go for a brief test drive. Turn the warmth onto full blast so the coolant start flowing into the heater core.

After the engine has actually been run for a little bit and also there is heat air coming the end of the vents, inspect the hoses for any leaks because we simply removed and also replaced them.

With the heater core cleaned out, the vehicle should warm up nice and quickly now. A good way to reduce the amount of sediment construct up is to frequently flush the end the cooling system. If the flush doesn’t help with the heater, one of julianum.net’s certified technicians would certainly be happy to assist you identify the issue.