Troubleshooting: 2000 Civic Heater Comes and Goes - What Could It Be?
Thread Starter
Trial User
Joined: Nov 2018
Posts: 3
Likes: 0
Troubleshooting: 2000 Civic Heater Comes and Goes - What Could It Be?
Hello,
Bear with me here. I'm new to fixing my own vehicles. I bought a 2000 Civic and the heater barely blows warm, and it takes literally 45 minutes to blow even lukewarm (if it decides to that day). Bad heater core? Clogged heater core? I just don't get why it would blow a little warm, after like 45 minutes of waiting.
I recently had a radiator hose blow (a 1000 miles ago), and I just assumed that was unrelated, but I'm mentioning as an FYI. If I just need to replace the heater core, should I do it on my own and just use Youtube? Or am I out of my league here?
Thanks for the help, apologies if this is a painfully obvious problem.
Bear with me here. I'm new to fixing my own vehicles. I bought a 2000 Civic and the heater barely blows warm, and it takes literally 45 minutes to blow even lukewarm (if it decides to that day). Bad heater core? Clogged heater core? I just don't get why it would blow a little warm, after like 45 minutes of waiting.
I recently had a radiator hose blow (a 1000 miles ago), and I just assumed that was unrelated, but I'm mentioning as an FYI. If I just need to replace the heater core, should I do it on my own and just use Youtube? Or am I out of my league here?
Thanks for the help, apologies if this is a painfully obvious problem.
Last edited by lcaot57; Nov 28, 2018 at 05:23 AM.
Honda-Tech Member
Joined: Mar 2008
Posts: 5,474
Likes: 46
From: Salem, Or
re: Troubleshooting: 2000 Civic Heater Comes and Goes - What Could It Be?
Heater cores rarely clog up, they usually leak before clogging. Two things that come to mind, #1 and the first I would check would be what's called the blend door, it's a plastic piece that directs air either through or away from the heater core. To check it turn the heat on full blast and climb on the passenger side floor reaching under the dash. You will see a couple of plastic arms with cables attached to them, these are what move the blend door. Move them each either way while checking the heat. When you move it the right way you will know right away. You will have nice warm air blowing on you. I've seen this problem on many civics, either the cable breaks or the cable stays let it move either way it makes your heater not function by bypassing it with cool air.
If this doesnt work turn the heat on and feel both your heater core hoses in the engine bay, specifically the one past the heater core valve. It should be hot, if it's not move the valve by hand and recheck. If it's still not hot bleed your coolant system once it's cooled down. Park on the steepest incline you can and remove the radiator cap (when it's not hot) and let it run with heat on full blast. Keep squeezing the radiator hoses and topping coolant level off till there isn't any air bubbles.
If this doesnt work turn the heat on and feel both your heater core hoses in the engine bay, specifically the one past the heater core valve. It should be hot, if it's not move the valve by hand and recheck. If it's still not hot bleed your coolant system once it's cooled down. Park on the steepest incline you can and remove the radiator cap (when it's not hot) and let it run with heat on full blast. Keep squeezing the radiator hoses and topping coolant level off till there isn't any air bubbles.
Thread Starter
Trial User
Joined: Nov 2018
Posts: 3
Likes: 0
re: Troubleshooting: 2000 Civic Heater Comes and Goes - What Could It Be?
Heater cores rarely clog up, they usually leak before clogging. Two things that come to mind, #1 and the first I would check would be what's called the blend door, it's a plastic piece that directs air either through or away from the heater core. To check it turn the heat on full blast and climb on the passenger side floor reaching under the dash. You will see a couple of plastic arms with cables attached to them, these are what move the blend door. Move them each either way while checking the heat. When you move it the right way you will know right away. You will have nice warm air blowing on you. I've seen this problem on many civics, either the cable breaks or the cable stays let it move either way it makes your heater not function by bypassing it with cool air.
If this doesnt work turn the heat on and feel both your heater core hoses in the engine bay, specifically the one past the heater core valve. It should be hot, if it's not move the valve by hand and recheck. If it's still not hot bleed your coolant system once it's cooled down. Park on the steepest incline you can and remove the radiator cap (when it's not hot) and let it run with heat on full blast. Keep squeezing the radiator hoses and topping coolant level off till there isn't any air bubbles.
If this doesnt work turn the heat on and feel both your heater core hoses in the engine bay, specifically the one past the heater core valve. It should be hot, if it's not move the valve by hand and recheck. If it's still not hot bleed your coolant system once it's cooled down. Park on the steepest incline you can and remove the radiator cap (when it's not hot) and let it run with heat on full blast. Keep squeezing the radiator hoses and topping coolant level off till there isn't any air bubbles.
I'll get right on trying this. Definitely seems like the most promising thing yet. Thanks and I'll circle back with an update ASAP!
re: Troubleshooting: 2000 Civic Heater Comes and Goes - What Could It Be?
If a previous owner has used any kind of stop leak in the coolant system to fix a leak, your heater core could be clogged. I would check the blend door first before you go pulling the heater core out though. It's not rocket science to replace, but a LOT of stuff has to come out of the way to get to it.
Thread
Thread Starter
Forum
Replies
Last Post
slowassBubble
Honda Civic / Del Sol (1992 - 2000)
3
Jan 13, 2010 11:07 PM