Anyone using Kat's or Zerostart lower rad hose heaters? - Page 2 - PeachParts Mercedes-Benz Forum

funola · #16 09-23-2013, 12:13 PM

Quote:

Originally Posted by charmalu

A Block heater is 400W.

Charlie

As opposed to a lower radiator hose heater which usually starts at 1000 and go as high as1500 watts.

Zacharias · #17 09-23-2013, 02:38 PM

Maybe you are thinking of the external 'tank' heaters that plumb into the heater hose. They start at about 850W and then 1000W and more.

The zerostart 1.5" lower rad hose heater I just purchased is rated at 600W.

Some of the larger ones for tractors and heavy equipment are more than 1000W.

ROLLGUY · #18 09-23-2013, 10:11 PM

Quote:

Originally Posted by funola

Easier to install yes, more efficient as far as heating the engine, no. It is more efficient at heating the radiator and heater core though. That's why lower radiator hose heaters are twice the power of block heaters, since it has to heat the block indirectly.

As far as I know, the law of physics that states that heat rises is still valid. Therefore, it stands to reason that a lower radiator hose heater plumbed correctly, will heat the engine better than a block heater because it is lower than the block heater. Also, heat will follow the path of least resistance (up the hose and into the block). The coolant in the radiator will get warm long after the entire block is heated up.

funola · #19 09-24-2013, 12:01 AM

Quote:

Originally Posted by ROLLGUY

As far as I know, the law of physics that states that heat rises is still valid. Therefore, it stands to reason that a lower radiator hose heater plumbed correctly, will heat the engine better than a block heater because it is lower than the block heater. Also, heat will follow the path of least resistance (up the hose and into the block). The coolant in the radiator will get warm long after the entire block is heated up.

Do you think Mercedes picked the wrong place to mount an engine heater? They should have put it into the lower radiator hose instead of the freeze plug?

Take a look at the cooling system diagram.
http://mercedes.thatchermathias.com/w123CD2/Program/Engine/615/20-005.pdf

The lower radiator hose goes up to the thermostat housing. Your lower hose heater has to heat the coolant in the hose up to the temperature of the thermostat to open it before the engine will get heated, that takes time and is inefficient. The block heater starts heating the block and head immediately. I agree that heat rises. The thermostat is higher than the freeze plug. Which is more effiecient?

compu_85 · #20 09-24-2013, 12:11 AM

I have a zerostart tank heater on my Jetta, it works well. But one problem is that if I only run it for an hour on a cold day it warms the coolant around the coolant temp sensor but not the block, so the glow plugs won't run and it has a hard time starting.

-J

funola · #21 09-24-2013, 11:57 AM

Quote:

Originally Posted by compu_85

I have a zerostart tank heater on my Jetta, it works well. But one problem is that if I only run it for an hour on a cold day it warms the coolant around the coolant temp sensor but not the block, so the glow plugs won't run and it has a hard time starting.

-J

How long do you have to run it to heat the block? How many watts is your zerostart tank heater and what is the volume of its tank? I suppose the tank is to lower the heat density and increase safety margins (of fire hazard)?