Anyone use a circulation tank block heater before?

[texasnick]

I'm new to the whole block heater business, and I'm looking to install one on my PITA to work on GT4. Frost plug replacement heaters seem to be the norm, but I have always found them a PITA to install (with a pornstar style face-shot to boot), and I'm also a bit wary about heating the coolant/block up in such a non-uniform way.

So, today I came across circulation tank style heaters. More specifically, I've been looking at the Zerostart/Phillips & Tenro 8000 series tanks. (found here on page 74... http://zerostart.com/UserFiles/File/2010_Zerostart_Catalog.pdf)
120V/750W, check-valve and thermostat controlled.

Seems to me there may be benifits to heating all of the coolant and having it circulate through the engine while the engine is off, from the perspective of heating different parts of the engine more uniformly.

Secondly, it looks pretty easy to install. Find a mounting point, cut lower rad hose, insert fitting, fit the other side to the heater core or something. Hose routing may need to have some thought put into it in order to get the warm coolant circulating correctly.

A lot easier/less hassle than a freeze plug type.

Has anyone used one?
What are the benifits and the disadvantages over (a) freeze plug type, and (b) lower hose insert type?

Price is something like $80 for PN 3308001 from Bumper to Bumper in the SE.

I'll probably end up using one of those magnetic oil pan heaters as well for the really cold days.

TIA
Nick

[Tik-Tok]

My '98 subie doesn't have a block heater, so I bought a circulating coolant one instead. I bought it last fall but haven't installed it yet though as it started fine all last winter.

My biggest concern with it (and why I haven't installed yet... asides from shear laziness), is that if your ECU is getting it's temperature reading from your cooling system, then when you start on a -30*C day, and your coolant is already warm(er), then the ECU won't be adjusting your engine parameters for a cold weather start. Also, cold thick oil is the worst part of cold weather starting, so it's not helping a whole lot in that department.

Block heaters are time tested true though.

[HHURICANE1]

Easier to install and IMHO better working is a lower rad hose heater. Get the one for your size of hose , cut said hose, install and refill cooling system. Being the lowest point they heat the fluid in the rad and the engine. I've had one in my Laser since new and it's always done the trick for me.

[Abeo]

I'd go with a block heater myself... warming the coolant does very little to warm the oil, at least with the block heater (which warms to coolant in the block) is that you get the oil temps up a little so it rolls over easier and does less damage due to thick oil at startup. I wouldn't worry about uneven block heating because the coolant is more or less going to heat up uniformly in the water jackets.

[Zero102]

Originally posted by HHURICANE1
Easier to install and IMHO better working is a lower rad hose heater. Get the one for your size of hose , cut said hose, install and refill cooling system. Being the lowest point they heat the fluid in the rad and the engine. I've had one in my Laser since new and it's always done the trick for me.

And I had a lower radiator hose heater fail and burn my car to the ground. My experience is to stay the hell away from them.


I've had the tank style zerostart heater on my last car (VW golf TDI) and the guys over at TDIclub use them religiously. They do a much better job than a frost plug style heater for a couple reasons:
1) They are 750-1200W vs 100-200W
2) They allow some mechanism to circulate the coolant in more than just one part of the water jacket

If you choose to fit one you need to think about the normal flow of coolant within your engine. If you provide a method of less resistance for the coolant as compared to passing completely through your engine then you may not have proper coolant circulation after installing the engine and may overhead badly on a hot day. If you connect one end of the heater on one side of the thermostat, and the other side on the other, you can end up heating your rad instead of the block, or having no coolant circulation.

They require more thought to install than a typical frost plug block heater but they also work many times better.

The advantage I found with them was that I had instant heat when I started the car as the entire engine was warmed to 60-80*C.

If you don't run synthetic oil I would still recommend an oil pan heater. Although the coolant heater will indirectly heat the oil pan (and it will heat it much more than a normal block heater), the oil pan may still be well below freezing on a -30 day.

[texasnick]

Thanks for the info guys.

I use full synthetic and I will be using a magnetic oil pan heater as well. I've seen even fully synthetic 10w30 get really sludgy even with the not-so cold temps we've been getting lately.

That's interesting regarding the ECU using coolant temp to determine cold startup parameters. I knew it did, just didn't think about it until you mentioned it. I'm pretty sure my car has an IAT sensor as well, so I think that would cover the fueling. Am I missing anything else this type of heater might cause the ECU to overlook that it shouldn't?

I'm thinking this would get installed with the inlet to the heater coming from the lower rad hose, and the outlet going to the heater core. Thermostat is on the front side of the motor, in the upper hose IIRC. That should heat the coolant in the block up, and once it's run for a while, t-stat will open and circulate the rest of the coolant. Do you think this setup will have the potential to overheat the engine in 30C+ weather? This engine runs quite hot to begin with. I wouldn't want that.

These things work on simple convection right? After hearing hurricane1's opinion, and realizing that heat rises LOL, what is the difference between the rad hose heater and this unit? Rad hose heater would heat up both rad water and engine water, circulation tank just the water in the block (with check-valve in place)?

Lastly, I think my coolant capacity is around 8L. Would the 750W heater be sufficient in -40C to warm coolant up to above freezing, or should I go with the 1000W or even 1500?

Again, thanks for the help guys. I'm a cold-weather noob.

[Zero102]

Usually the lower rad hose is sloped a little bit up towards the radiator and the lower rad hose heaters do more to heat the radiator than the engine. That and my bad experience are more than enough for me to recommend against them.

With your setup the tank heater should heat only the block. As long as you don't tap in on the water pump outlet, but rather near the suction side of the water pump you should be just fine for coolant flow.

As for the heater sizing question, 750W should be adequate. My VW had ~7L of coolant and with a 750W heater I had very reasonable temps even in -30*C weather.

With my VW the belly pan sealed quite well to the body, so I used pipe insulation to block the vents on the front during the winter, this let the heater keep more heat in the engine when I parked facing the wind, and helped the car warm up quicker too. Dunno how that would work in your situation since you said your engine likes to run warm.

The ECU does use the coolant temp to modify the engines fueling, but within 10-15 seconds of startup it will read the engines real temperature. The ECU doesn't modify fueling enough for it to not start in cold weather because it has the temperature wrong. It may run very slightly lean for a few seconds, but a far bigger factor in the fueling is the intake air temperature sensor, whose results will not be affected.


The heater I used was a 750W heater without a "thermostat". They all have overheat protection (switch off at 90 or 95*C), but some also have a much lower set thermostat (40-60*C) which switches them off far sooner. I used one without this, it cycled on the high limit switch frequently and never failed.

If you are interested, I do have a 750W tank style heater I bought for a previous car, IIRC it has the 60*C thermostat in it and I would give it away for free since I have no use for it now. The box is worn out and a bit banged up and the kit is missing a couple pieces, but it should still have all of the fittings you need to install it (except the lower rad hose adapter, I don't think any of the kits come with this).

[D. Dub]

Originally posted by Abeo
I'd go with a block heater myself... warming the coolant does very little to warm the oil, at least with the block heater (which warms to coolant in the block) is that you get the oil temps up a little so it rolls over easier and does less damage due to thick oil at startup. I wouldn't worry about uneven block heating because the coolant is more or less going to heat up uniformly in the water jackets.

Circulating heater works 10X better than a block heater. It heats the entire engine top to bottom including the oil to some degree -- that and a winter weight oil are all you need.

[Zero102]

Originally posted by D. Dub


Circulating heater works 10X better than a block heater. It heats the entire engine top to bottom including the oil to some degree -- that and a winter weight oil are all you need.

Yup, the block heater is actually just a small element tucked into a water jacket, it does much less to heat the oil or distribute the heat across the engine than a proper coolant heater would.

I wish more cars came with this style of heater :)

[Guillermo]

from what i've read, and based on OEM for basically ALL car manufacturers, frost plug heaters are the best.

[Abeo]

Originally posted by D. Dub


Circulating heater works 10X better than a block heater. It heats the entire engine top to bottom including the oil to some degree -- that and a winter weight oil are all you need.

I guess I'm not familiar with that style of heater... does it actually mechanically circulate the coolant, or does it rely on convection to circulate?

Sounds (to me) like an overly complex solution to a simple problem, but if I was driving a diesel again I'm sure I'd want one over a block heater.