No heat,found the culprit

[Blueberryyum02]

Ok I been fighting this no heat situation after I replaced all plastic, the last thing I replaced was the degass bottle and suddenly no heat.

Dreading the fact I bought the dorman bottle, I suspected that's my problem, nope finally got around to unplugging the DCCV after countless days of bleeding, and fooling around with the degass bottle, it's suppose to default to full heat right nope nothing. The hose from the tee leading to it is cold and lacks pressure also the heater core hoses are cold and lacks pressure. Which I'm leaning towards the valve is stuck in a closed state which is stopping the flow of coolant. Which means I still have air in the system.


What I don't understand is why would the heater bleed show signs of coolant if indeed the valve is in a closed position?

The only time I get a good stream is if I give it gas, and that only happens after it's released then I goes back to a trickle where it stops then trickle and so fourth and so on.

 

[oddball]

For the trickle/stream, verify that the aux pump is running. My '02 - for whatever bizarre reason - refused to run the aux pump. I eventually switched to an '01 climate control head unit as other '02 units did the same thing. I won't pretend to understand it.

The valves may be open enough to let a little water though but not enough to actually heat. Hard to tell until the unit is removed and inspected.

 

[joegr]

...What I don't understand is why would the heater bleed show signs of coolant if indeed the valve is in a closed position?...

It seems that a lot of people have trouble understanding this.
The heater circuit is a loop. Coolant flows into the two cores after passing through the two DCCV valves. It then flows out of the core via the return hose. It wouldn't work if it didn't have an in and an out. You can cut and clamp off the hoses from the DCCV to the core. There will still be coolant and pressure in the heater core. It just won't be flowing. The whole cooling system is at a higher pressure than the outside air. If you open the bleeder, coolant should always come out. If it doesn't come from the supply hose(s), then it will come from the return hose.

All this said, I'll be really surprised if your problem is that the DCCV is suddenly stuck closed on both valves.

 

[Blueberryyum02]

It seems that a lot of people have trouble understanding this.
The heater circuit is a loop. Coolant flows into the two cores after passing through the two DCCV valves. It then flows out of the core via the return hose. It wouldn't work if it didn't have an in and an out. You can cut and clamp off the hoses from the DCCV to the core. There will still be coolant and pressure in the heater core. It just won't be flowing. The whole cooling system is at a higher pressure than the outside air. If you open the bleeder, coolant should always come out. If it doesn't come from the supply hose(s), then it will come from the return hose.

All this said, I'll be really surprised if your problem is that the DCCV is suddenly stuck closed on both valves.

Joegr that is what took me so long on figuring it out, cause I couldn't see it being stuck closed when I was calling for full heat right before I shut it off for the cool down part of the bleed procedure. But after I unplugged it that Is what confirmed it for me.

 

[Blueberryyum02]

For the trickle/stream, verify that the aux pump is running. My '02 - for whatever bizarre reason - refused to run the aux pump. I eventually switched to an '01 climate control head unit as other '02 units did the same thing. I won't pretend to understand it.

The valves may be open enough to let a little water though but not enough to actually heat. Hard to tell until the unit is removed and inspected.

That's funny cause I have gotten that aux pump to come on, by supplying voltage from one of the empty fuse slots, cause the are 12 volt positive tabs. But when it comes to it coming on by the dtc I have heard it come on a few times over the years with the car off. And have never felt full heat at idle, I just assumed it was the plastic coolant pipes, now that they are brand new. I think it could be a issue with the dtc. As well.