DIY: Heater core replacement

[foama]

My clogged heater core had nothing added or changed to the OEM coolant, but was clogged with lime scale. That only then became obvious after it was cut to pieces. If I would have know before, I would simply have flushed it with scale remover.
Before you give up, maybe you want to try lime scale remover?

[Morphector]

I’m in the process of cleaning my heater core with mineral spirit
I’m using a small pump to circulate the mineral spirit in the heater core with an inline heater with an internal 100f thermostat


After running for 8h I noticed the colour is starting to be really yellowish, just hope it’s a good sign the flux in it is starting to melt
At the beginning

After around 8h of runtime

[Top_Fuel]

Let us know if you see any improvement when you're done.

I figured if I ever tried something like this, I would let it soak for several hours and then use a pump like you are doing. You might want to try reversing the flow of the fluid as part of the cleaning process.

[Morphector]

Let us know if you see any improvement when you're done.

I figured if I ever tried something like this, I would let it soak for several hours and then use a pump like you are doing. You might want to try reversing the flow of the fluid as part of the cleaning process.

I’ll try reversing the flow tomorrow morning than I’ll flush it with my garden hose.

Pump is really crappy as it’s not pushing a lot, there’s only a trickle flow coming back from the core….

[Morphector]

After 24h of running mineral spirit trought my heater core the liquid is really getting darker but there’s still not that much more flow
You can clearly see that there’s more sediment in the bottom of the barrel


I stuck the garden hose directly in the core in both directions and it clearly unclogged
As the flow greatly increased with the same pump

There’s clearly now a bunch of crap in the bucket that clearly doesn’t want to mix with the mineral spirit

[Top_Fuel]

Do you have a link to the pump you are using?

[Morphector]

Do you have a link to the pump you are using?

Just bought a cheap ass fountain pump at a local hardware store, took one of the cheapest one that could only lift 3 feet high…
The output was only 1/2 inch but a 5/8 hose would fit with a collar holding it

I’ll still pump mineral spirit for 24hr than flush it again tomorrow and report back with vent temperatures

[klroger]

I’m in the process of cleaning my heater core with mineral spirit
I’m using a small pump to circulate the mineral spirit in the heater core with an inline heater with an internal 100f thermostat

Nice, I like the Idea of using the fountain pump. What are you using for the inline heater?? My heat is OK so far, but this may be even kinda regular (5 or so) year maintenance going forward.. Thanks Lots!!!

[Morphector]

Nice, I like the Idea of using the fountain pump. What are you using for the inline heater?? My heat is OK so far, but this may be even kinda regular (5 or so) year maintenance going forward.. Thanks Lots!!!

Heater is a standard 1000w heater with a 100-110f thermostat that we installed on every standby diesel generator…


Just finished reflushing the heater core this morning with garden hose, flushed it again with déminéralised water than coolant and plugged everything…


Went for a 5 min drive and heat is nuclear hot compared to before, there’s still a slight difference between driver and passenger side.

Mine was so clogged up that the engine was overheating at 220f and fans were almost constant…

Now it’s barely sitting at 195-200f…


Talked to my father who is a retired college teacher and he may still have some connections to test the goop in a spectrometer in the next couple of weeks so I’ll keep it for him.