I have a 98 civic and I'm not getting any heat. I disconnected the heater hoses at the firewall/valve and ran put an air hose on one end and had flow going through. The valve seems to be open. I'm not sure what else to check. Radiator hoses are hot but heater hoses are not even when heat is on. Any clues?

 

Maybe the thermostat is stuck open and needs to be replaced.

Does the cluster temp gauge indicate that the engine fully warms up?

 

Thanks for the tip. Suck open was putting it mildly.



Now I get heat if the engine is reved but not when it's idling. I'm hoping a flush will solve the problem.

 

Um, where is the rest of the T-stat? hopefully the bits didn't end up in the cooling jackets of the block

 

Good question. I'm hoping it was removed intentionally. The car is new to me, so I don't know the history.

 

The parts would have most likely ended up in the radiator first though...

 

Bleed the cooling system.

https://honda-tech.com/forums/showth...1#post39830585

 

I've got it working. I used a pipe to create a nozzle for my air hose and backflowed the heater core. Now I have heat.