Kat's 24150 150 Watt 4"x 5" Universal Hot Pad Heater

I purchased several sizes/wattages of these hoping to find the right sizes for my snowblower and ATV engines. The trick is to find flat open spots on or near the bottom of the oil reservoir, clean it well, and stick the appropriate size of heater there. The instructions say DO NOT use gasoline or acetone to clean the spot, and you must believe it. The first one I put on I used acetone (I know but it's all I had) to clean the spot, and the adhesive does not stick well. On the others I used mineral spirits, and they stick like glue. They stink a bit when heated, but that is going away with use. I also used a 50 watt one to keep a bird bath de-iced, and it worked perfectly down to 5 deg F. No thermostat, so a good idea is to just plug them in a few hours before you use the equipment, or put them on a timer. But, they don't seem to overheat if you put the appropriate wattage on the appropriate size of reservoir and that's a guessing game. Five stars because they are inexpensive and do exactly what they are meant to do.

This works pretty well on the oil pan of my vehicle. It does not have a thermostat. It does need insulation on the back side so that it does not lose heat. I plug it in about 2 hours before I use the vehicle and it does the job of preheating. I also have one of these to keep our Moose pond thawed. The unit is submersible. So far the animals haven't eaten it. So you can use this item for a lot of things, but it has to be attached or submerged in something.It will overheat in the air, by itself. I rated it less than 5 stars because it is not insulated on one side and it does not have a thermostat.

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put this on the oil pan of my 3 series bmw. i live in the warm south but keep this plugged in 2 hours before startup each morning. engine starts much healthier sound and 5 speed stick shift tranny shifts smoother in cold weather @ startup b/c the tranny case gets conductive heat thru the oil pan.

if you live in warm climate I would not reccomed keeping this plugged in overnight....it'd be a waste of energy and these get darn hot. I'll zap the exterior temps of my oil pan and tranny case and report back with the case temps from my infrared temp gun.

overall product works great. i did install with a bead of high temp silicon around the edge (after first cleaning the oil pan of grime with some type of solvent..acetone maybe).

Put it on a timer and let it run an hour or two before startup. its bound to reduce wear on engine. well worth the money b/c it costs mere cents in electricity.

UPDATE AS OF 12/2/2012 with the temps from a laser temp gun:

OK Here are the temps I zapped:

w/ no power to the stick-on heater

Ambient in garage = approx 68

Laser gun temp on oil pan = 68

Laser gun temp on tranny case = 68

Laser gun temp on lower block = 68

Laser gun temp on vanity cover = 68

OBDII temp from coolant temp sensor in head = 66.3

After turning on pad for 1 hour:

Ambient in garage = approx 68

Laser gun temp on oil pan = 94-86 depending on where I zap it

Laser gun temp on tranny case = 72

Laser gun temp on lower block = 78

Laser gun temp on vanity cover = 69

OBDII temp from coolant temp sensor in head = 68.0

After turning on pad for 2 hours:

Ambient in garage = approx 68

Laser gun temp on oil pan = 92.6-99.5 depending on where I zap it

Laser gun temp on tranny case = 75

Laser gun temp on lower block = 83.6

Laser gun temp on vanity cover = 70.7

OBDII temp from coolant temp sensor in head = 71.6

After turning on pad for 2.5 hours:

Ambient in garage = approx 68

Laser gun temp on oil pan = 93.5-102.2 depending on where I zap it

Laser gun temp on tranny case = 75.5

Laser gun temp on lower block = 83.9

Laser gun temp on vanity cover = 71.6

OBDII temp from coolant temp sensor in head = 71.6

I'm using this heater in Texas to warm up oil before short trips. So what do these numbers indicate to me? They indicate that the oil temp is at best climbing 30 degrees over abient temp. Thats not as favorable as I was hoping. I'm going to put another 150 wattt on the oil pan and see if I can get more heat to the oil before startup b/c short trips w/ cold oil is not good for the engine.

If you live somewhere up north where its cold and get snow then I would highly recommend the 250 watt pad if your oil pan holds enough oil. From what I hear a 250 watt will warm the oil and possibly provide enough heat to thaw snow and ice from hood and windshield. From kats I believe the specs on side of heater for a given oil capacity are as follows:

100 watt for 2-5 qts engine oil

150 watt for 5-8 qts engine oil

250 will for 8-20 qts engine oil

p.s. the silicon sealant I used was from auto parts store and it was black in color. the sealants have a heat rating on back and the black stuff was rated to 400 deg F.

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This is a great product. I was having trouble getting my tractor to start in the cold MN winter. I bought this heater and stuck it to the bottom of the oil pan. I also bought the Katz battery warmer and wrapped the battery. From the day I installed them my tractor started like it was 80 degrees in the middle of summer. We had an extremly cold winter this year and my tractor started with no trouble everytime.

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I was looking at this and one of the magnetic heaters & wasn't sure which was best, so with both being ~$25 (where it's not like buying a car) I got one of each (figuring I may put one on a car and keep one for other uses). One of the places I wanted to be able to use them was on a small engine (like for a generator or snow-blower) and with those having an aluminum block (where the magnet won't stick) I got a steel plate ~1/8 thick I could bolt up to the engine base. I put the magnetic heater on the plate (without it on the engine yet) & plugged it in, after 1 minute the plate seemed totally cold still. I pulled the plate off and put my hand near the unit where it's base was warm, so put it back on. Apparently, the magnetic bars stick out enough that it leaves a 1/16-1/8 gap between the base creating the heat and the attached plate. So the heat either needs to "jump" the air gap or all be funneled thru the little magnet bars to get where you want it to go. If we're talking about outside temps of 20 or less where you want to warm an engine, trying to warm the air around it doesn't seem great to me.

So I then tried placing this "heating pad" unit on the same plate (after cleaning it as per instructions and putting a bead of silicone around the edge that needed to dry). With it plugged in, the plate is too hot to hold within 1 minute (and was at 200 degrees within 2 minutes). So it heats fast, but if you're not using it on something big enough to easily absorb all of it's heat you may have an issue with it NOT have any temp control (although they say it has such).

So my conclusion is if you want good heat transfer, the heat pad unit seems better with full contact. If you want an easy to slap-on or removeable unit, the magnetic one may work.

Just be sure to look at what you plan on mounting this on. If thinking of your oil pan, you want one that is smooth with no "ribs" or ridges and has a flat surface the size of this. They say to "use a roller to be sure of no air pockets under it" and if the pan has ridges or you try to go around a corner, you'll likely have issues with it sticking well. Most engine blocks don't have this big an open/smooth space for it, so oil pans may be the only good place.

Note: Both units say in the instructions "Don't place on painted surfaces because it'll damage the paint", so you want bare metal for either (even if it means striping off paint). Also if you're wondering "How do you warm a generator engine with power out (which is when you need it)?" I have a deep cycle battery & inverter that should work for ½ hour, then with the gen going I can recharge.

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