[EcoCivic]

Hello all, I have recently installed a block heater on my 2004 Honda Civic 2.4 (the kind that replaces the block drain plug) and I quickly noticed that the outside brass part of the block heater around the heating element gets incredibly hot within seconds of plugging it in. Never used a block heater before but I would assume that this is normal. Anyways, I am thinking about wrapping the exterior of the heater in a piece of a fiberglass insulation strip I have to keep the heat in the coolant directly surrounding the element and therefore keeping more of the heat in the engine. A decent size chunk of brass can dissipate quite a bit of heat at a well over 100 degree F delta T and I would much rather have that heat in the engine than wasted heating the air surrounding the heater.



The only concern I have is whether insulating the exterior of the heater could cause the element to overheat and fail prematurely, boil the coolant in the heater around the element, etc. I wouldn't expect that this would be a problem since I would think the coolant in the engine block is more than enough to adequately cool the element with or without the exterior of the heater dissipating heat to the air, but I don't have much experience with block heaters so I wanted to check first and any advice is greatly appreciated.



This is what the block heater I installed looks like. As you can see, quite a bit of the heater is exposed to the outside air.