Heater valve, is it 100% closed when on climate on cold?

[citrus3000psi]

I don't have a heater core and had this line looped with some AN hoses. I'm removing all my AN lines that do not go to the firewall/engine bay with hard lines.

I guess I don't understand the purpose of looping this line, the internet pretty much says to loop it and your car is fine (which I blindy did in the past). But if the heater valve shuts 100% then it makes more sense to block these. As you would just be recirculating hot coolant from the head right back into the block.

I still have the line from the intake to the thermostat housing so the coolant can recirculate through the system when the car is cold. If anyone could confirm the heater valve is 100% closed I will block these off. If it allows a small amount though I would install much smaller loop line.

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[aklackner]

Heater valve is a ball valve, if it’s closed then nothing should be coming through. Be careful though if there’s any dead-end passage it will be a b*tch to bleed your coolant system.

[citrus3000psi]

Heater valve is a ball valve, if it’s closed then nothing should be coming through. Be careful though if there’s any dead-end passage it will be a b*tch to bleed your coolant system.

I just wasn't sure if the valve closed all the way. I will plan to block them off. When I fill the system with coolant I can crack the plug on the head and let any air out if there is a pocket where something can form.