Coolant heater

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
Getting ready to install a Zerostart 8000 on my '05 PD jetta. Question: why does the check valve need to be removed from the heater?
Thank you in anticipation.
 

maxwellp

Veteran Member
Joined
Oct 22, 2011
Location
VERONA, WI
TDI
1998 TDI Beetle
The check valve works to make sure the coolant flows in one direction when it is heating. Where we place the heaters on these cars coolant flows in the opposite direction when the engine is running...So it can't have a check valve.

http://www.frostheater.com/frostheater.htm
 
Last edited:

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
The check valve works to make sure the coolant flows in one direction when it is heating. Where we place the heaters on these cars coolant flows in the opposite direction when the engine is running...So it can't have a check valve.

http://www.frostheater.com/frostheater.htm

That's what I've been reading. But, what I don't understand is why the two hoses can't just be reversed so the heater is moving the coolant in the same direction as it naturally moves...Is that a dumb question? Where do the two hoses going into the oil cooler go? If I reversed the hoses, would it try and move the coolant against the thermostat instead of into the engine?? I don't get it...:eek:
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
I found a coolant flow diagram for the ALH motor. I hope it's similar if not identical to the BEW?? In it, it appears that the oil cooler is part of the bypass circuit for when the thermostat is closed. It seems to me that you could connect a heater in either direction, and the engine is still gonna get warmed. So...why don't ppl just leave the check valve in place, and hook the heater up so its moving coolant in the same direction as the pump. It seems to me that it would be more efficient with the one way valve in place?

 

david_594

Top Post Dawg
Joined
Feb 28, 2004
Location
Cheshire, CT
TDI
2000 Jetta GLS Silver
That's what I've been reading. But, what I don't understand is why the two hoses can't just be reversed so the heater is moving the coolant in the same direction as it naturally moves...Is that a dumb question? Where do the two hoses going into the oil cooler go? If I reversed the hoses, would it try and move the coolant against the thermostat instead of into the engine?? I don't get it...:eek:
The issue is the coolant moves via convection since there is no pump in the zerostart. So if you reverse the two hoses the heated coolant will still be trying to move in the same direction.
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
The issue is the coolant moves via convection since there is no pump in the zerostart. So if you reverse the two hoses the heated coolant will still be trying to move in the same direction.

If I reverse the two hoses, the coolant will be convecting in the opposite direction, no? Doesn't matter, I guess. This is where everyone puts them. They put them in opposite normal flow, and remove the check ball. It seems to work for ppl, so that's what I will do. It just doesnt make any sense to me.
Does anyone know what the height difference is between the water pump and the side of the head where the coolant comes out. Zerostart requires the coolant to be pulled into it from a low area on the block and the heated fluid put back up high. That might explain why we need to mount it backwards?
 

maxwellp

Veteran Member
Joined
Oct 22, 2011
Location
VERONA, WI
TDI
1998 TDI Beetle
The heated coolant will always go up, opposite normal flow. So running it goes one way. Plugged in it goes the other. that's why you remove the check valve.
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
OK, so I removed the check valve in preparation for installation this w/e. Its at the bottom, on the inlet fitting. Comes out really easy. I just screwed a 5/16-18 machine screw into the black plastic body and pulled it out by hand. 10secs, max.










 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
I've noticed that most ppl mount these heaters under the battery. The 1500W unit is quite large, so mounting it here seems like quite a tight fit. The power steering line uses up a lot of room in this area. Has anyone mounted their heater inside the front fascia, ahead of the left wheel? There's a crapload of room here. What would be the downsides of placing the heater here??
 

david_594

Top Post Dawg
Joined
Feb 28, 2004
Location
Cheshire, CT
TDI
2000 Jetta GLS Silver
There shouldn't be any real issue mounting it there. Thats where the webasto gets mounted. My only concern would be making sure its not making contact with anything that could melt(like the fender liner).

Typically people use a different style zerostart heater that mounts much more easily below the battery.
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
I put the car on stands and pulled out the wheel liner. I like this spot the best. Its the lowest you can go while still being enclosed, and there's a ton of room here. The only hitch is having to run the intake line through the plastic engine cover. The output from the heater would be no prob as it would just loop over the frame rail back to the engine. I'll have to make a bracket of sorts to keep it from floppin around as well.

 

david_594

Top Post Dawg
Joined
Feb 28, 2004
Location
Cheshire, CT
TDI
2000 Jetta GLS Silver
Find the mk4 webasto install instructions. They will give you some ideas on how best to mount it in that area along with ideas for routing the coolant lines.
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
All I could find was this...
http://pics.tdiclub.com/data/500/1305Standheizung_supplement.pdf

It's like he's doing surgery in some of the pics, towelling off the rest of the engine as he works. It's not very helpful for me in this case, though.

I'm gonna use my dremel with a ball nose end mill and cut a hole in the plastic belly cover for the intake hose to pass thru. The heater came with a generic bracket which I think I can use to mount the heater here with a few mods.
 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
This is what I was able to cobble together for a bracket. The round band part actually comes with the heater, so that saved some time. I added a couple of bends to it and stitched it to the upright piece. The bottom of the battery tray area has a couple of extra holes in it, and thats where I decided to bolt it. I hit it with some tremclad, and the damn thing is still tacky. I have to go to work in the morning, so it has to go in as is.

 

its_go_time

Member
Joined
Mar 27, 2011
Location
Toronto
TDI
05 jetta
Well, here's what this DIYer ended up with. I tested it out this evening on a stone cold engine. With outside temp at about 0C, one hour of operation got the engine up to full temperature when I turned the key to run. The engine was warm to the touch. Not bad, but I'll wait till Feb and -30C to call this one.




 

SheeB

Veteran Member
Joined
Jul 8, 2007
Location
Ottawa, ON
TDI
2001 Jetta GLS Manual
The temp guage will read 90c initially but once the coolant starts circulating expect it to drop rapidly. Either way, the initial start is easy :)
 
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