Beware of Thermex brand front heater core

[dhaavers]

[greebly]

[Altoona]

[Slimvest]

Pulled my Thermex yesterday and replaced it with a used OEM core that I pressure tested first.

The Thermex core looked to be full of coolant when I pulled it but was not producing heat. I was expecting air entrapment. I have to wonder if the design paired with the flow rate of the vanagon coolant system just doesn't allow for coolant to circulate through the Thermex.
_________________
'87 GL w/ Reimo top

[detoxed]

Anybody using the Brassworks core? Feedback other than pricey?

[Slimvest]

I've been working with CIP, whom I bought the Thermex core from, on returning the part. They reached out to the supplier and said there was indeed a product recall on the Thermex core.

I've been offered credit but am trying to get a refund.
_________________
'87 GL w/ Reimo top

[SyncroChrick]

[DanHoug]

okay, i'm freakin' out a little bit. have a new Van Cafe heater core on the bench i'll be putting in very soon. worrying that it is the dreaded Thermex but take a look at these photos... it is different from what Fogerty1970 posted. please make me feel better!

first my VC core overall

now, looking down the inlet/outlet. notice how there is not a restriction as per the Thermex photo further below. it's just full bore. i also shined a strong light in the openings and there was zero light transmittal between the inlet and outlet.

and finally, a repost of the photo from Fogerty1970 of his Thermex inlet:

so. tell me the VC isn't a Thermex and make me feel good!!

-dan

[MsTaboo]

[SyncroChrick]

[Sodo]

That’s an interesting observation that lack of heat up front can be dependent on components in the rear heater area.

Can a defecive heater core be identified by a simple flow test with a garden hose?

Would be interesting if someone with a Thermex core AND a OEM core (& others?) could set a garden hose at some calibrated flow rate and compare the output flow of the two cores.

It’s fairly easy to determine flow rate with a stopwatch and a 5-gal bucket. If the bucket is half-full in 30 seconds the faucet setting is 5 gallons per minute. Perhaps a good test can be Samba-developed so folks have better confidence before closing up a das project.
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[jberger]

I'm not buying it.. Reduced flow would allow the fan or other air flow to pull more btu's from the available heated "coolant" leaving a luke warm heater box.

I have personally pulled a fully functional OE heater core to replace with a thermex only to end up with Zero heat... It has nothing to do with original flow characteristics and everything to do with the overall fabrication of the replacement core. Are the passages too large? Too restricted? Internally blocked? The latter is what agrees with me. How can the input side of the core be hot and the drivers side remain Ice Cold... Shameful

J

[Sodo]

[jberger]

[DanHoug]

i don't think the heat issues with the Thermex were from reduced flow... it was short-circuiting as i recall. someone shone a light in one pipe and could see light in the other.

i know on the core i have there is not light between the passages but before i put it in service am going to hook it up to the faucet and take an IR movie of changing the water from cold to hot to see the heat flow pattern thru the core. that should identify whether there is any short-circuits on this core.

-dan

[dhaavers]

^^^ Wise.

Who'da guessed in this day and age we'd still have companies
trying to figure out how to make a heater core that works...???



- Dave
_________________
86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS>

[danfromsyr]

companies make parts to sell not to work.
by the time the returns come in they've cashed out the company .
and it's the new holding company's problem.
_________________

[Zeitgeist 13]

The short circuit theory makes the most sense to me. The coolant flow will take the path of least resistance, and thus create a semi-permanently cool/cold eddy inside the core--flow goes in and immediately out again. I've seen radiator cores nearly completely occluded with scale and they still were able to shed heat, which leads me to think the tiny passages theory isn't quite telling the whole story here.
_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[DanHoug]

here it is... i took an infra red video of cold and hot water flowing thru my new Van Cafe heater core, purchased Oct 2017 for $125, don't know what brand they sell. water inlet/outlet is at the bottom left of the screen.

i have confidence in this new core that it isn't short circuiting and has even flow thru the element. i'll install it!

https://youtu.be/Hn-7Z4osCos

-dan

[dhaavers]

FIFY: