Kats heater FAILED AGAIN
 

Yep thats right. Got my replacement Kats heater and got it installed. Got the coolant topped off and bled good. Drove the car for a while to get the system aired out good. Let the car cool off. Plugged it in. It was alright for about half an hour, then NOTHING.

I dont believe this crap. I still have to send the first one back and now I gotta send the replacement back. Im getting a REFUND this time.

What the deuce am I doing wrong?! I felt the heater hoses get hot, the thing just stops working. Is a 1500w too much? Is the heater getting too hot too fast and theres just not enough coolant system there to keep it from burning out?

Maybe Ill get the refund and order the 600w model. I dont know, I really want a block heater but this aint a good impression at all.

is your dial inside set all the way to hot?

These dont have dials... do they? Theres nothing on them. They say they are thermostatically controlled though. If they are then they shouldnt burn themselves out right?

I dont get it.

My Kats heater still works since last winter. I wonder why yours is crapping out?

I don't even think my Jeep is running 1500w. I'm running 1000w on my block heater.

Im beginning to think its the way its installed thats killing it. I have it tapped in line with the heater hose going into the heater core, rather than having it tee off the lower rad hose. It doesnt quite get the low-to-high thing it supposed to, but I wouldnt think that would kill the heater *that* quickly.

From the bottom of this page
And from this pdf published by the manufacturer.It's no accident that 'trapped air/incompletely bled system' are near the top of each list. I'd have put it at #1. If a pocket of air gets trapped in the tank heater, you can burn the element out in seconds.

Look at where the heater hoses on your vehicle connect to the engine. One comes off the engine at a significantly lower point that the other. That is the one you want to cut into if you're connecting both ends to the tank heater rather than running a separate hose from 1) a tee added to the lower radiator hose or 2) from an engine block drain port. Adding a hose (from lower radiator hose or block drain) makes it much easier to get all the air bled out of the system!

While you're looking at heater hoses, look at where they connect to the heater core and/or how they run through the firewall. If they run/connect side to side, you're done looking. If their is an upper heater hose and a lower heater hose, make sure the lower heater hose is the same one that connects lower on the engine. If it is not, the heater hoses are probably reversed - which makes it much harder to get all of the air bled out of the system.

Every part of the tank heater should be lower than the lowest hose connection at the heater core.

Last but not least, ideally the arrow on the side of the tank heater should point straight up at the zenith. If your installation is going to vary from perfection in this matter, let the error be less than 12*.

I'd do the resistance test like last time, but poke the DMM probe through the cord insulation right where it enters the unit. That way you rule out a cord failure and know it's more likely the element. Then go from there.

I'd think the heater core would be far inferior to the lower rad. hose, due to the amount of water available to it and the convection currents likely to develop in the hose, or lack thereof. With 1500W you are going to heat the water up quick, and if it can't convect well enough, it will boil, leaving you with vapor that has very low specific heat --> dead heater.

^ I second gascort. 1500 W seems way overpowered for a heater core hose. My frost plug style heater only pulls about 420 W, and that's plugged directly in the engine block.

I installed one of these and last night was the maiden run. a 50ft extension cord (14ga) apparently got so hot it melted my bumper. This is the 1000w unit since they were out of 850w units. I am going to try a 25' 12ga cord and see if it helps.

I don't think I need to mention my car wasn't warm this am. Too bad, record colds here (1*f right now without a windchill)