-15F outdoor air temps = luke warm cabin heater air temps

[ctmurray]

I am in Minnesota also, each winter has a week where we never get above zero. But the cabin heater has always been great (2006 if I recall correctly). Previously I had a T100 and this really had a weak heater. The gas mileage really goes down though.

[a priori]

I can't offer you advice based on experience with Gen 1 in cold climates, but I do suggest you take a look through John1701A's website. (He posted early on in your thread and referenced his own site.)

I have a 2007 Gen 2, and I've been grill blocking both winters I've had the car. I find it makes a significant difference in how quickly I get heat from the car. When it got down to -24F about two weeks ago, it was impossible to get heat for the first 10 minutes of driving. This is no different than my previous cars, however, so I am not concerned with the heating ability of my Gen 2.

I wish you well, and I re-state my suggestion that you look to fellow Minnesotan John. He has had both the Classic (Gen 1) and Iconic (Gen 2) Prius.

[ctmurray]

Originally Posted by a priori

I can't offer you advice based on experience with Gen 1 in cold climates, but I do suggest you take a look through John1701A's website. (He posted early on in your thread and referenced his own site.)

I have a 2007 Gen 2, and I've been grill blocking both winters I've had the car. I find it makes a significant difference in how quickly I get heat from the car. When it got down to -24F about two weeks ago, it was impossible to get heat for the first 10 minutes of driving. This is no different than my previous cars, however, so I am not concerned with the heating ability of my Gen 2.

I wish you well, and I re-state my suggestion that you look to fellow Minnesotan John. He has had both the Classic (Gen 1) and Iconic (Gen 2) Prius.

I just wait for the heat to come on automatically (the heat is "on" but the car is waiting until it can provide warm air). I like this feature. At least I am not blowing cold air on myself.

[a priori]

Originally Posted by ctmurray

I just wait for the heat to come on automatically (the heat is "on" but the car is waiting until it can provide warm air). I like this feature. At least I am not blowing cold air on myself.

I understand what you are saying, but I believe you've missed my point.

When it is -10 or -20, the heat, though turned to "on" will not begin providing heat until the engine has warmed up to a minimum point. If you have an electric block heater or you employ grill blocking (or both, for an even greater impact), you will arrive at that engine temperature sooner, thereby providing "auto" heat that much earlier. An alternative, if MPGs are more important to you than toasty toes, is to wait for 5 minutes before turning on any kind of heat. At that point, you could put the heat on a low setting, or simply turn it to Auto.

Regardless of the above issue with MPGs, you've stated your issue with the cabin heat. I am suggesting, with anecdotal evidence in support, that you will warm up sooner and more completely if you are engaging one or both of the above-named techniques. Grill blocking is less expensive, and it will provide you with a very significant chance of a "warmer sooner" experience. It also will continue "giving" you better heat, because it will keep the ICE from losing its heat as you drive.

I've just started to enjoy the EBH (THANK YOU FIRE ENGINEER!), and I've noticed both quicker warming and higher MPGs. Hmm . . . No, I'll still say you should start with grill blocking, but don't ignore the benefits of an EBH.

[DaveinOlyWA]

i can agree that putting on heat, even in the auto setting, will not blow cold air but will start blowing much too early and greatly delay effective heating much longer.

i have seen during winter (relatively mild compared to you guys!!) during real cold snaps of 20-25ºF where water temp is 150º, turn on heat and water temp will drop to 140º in a few minutes. so what i do that is effective (it really depends on specific temperatures, so experimentation might be the key here) is let it heat up to 175º then turn on heat, turn off heat when temps hit 155º. wait for it to heat back up and so on.

now, the unfortunate thing about my area is the 99.9% humidity every winter morning (rare is it when its not saturated) requiring defrost to run which is not temperature controlled. iow, it will run even when blowing straight cold air...

[LeviSmith]

Doesn't look like anyone has posted here since it was cold. (:

I believe my 03' Prius' heater is worse off than normal because while troubleshooting a blown headgasket I put in some radiator sealer and I fear it is partially blocking the heater core.

First off is the question of if anyone knows a good idea of getting it cleared without spending a fortune?

Next question is if anyone has added some sort of supplemental heat? we've got that nice electrical source there, I was trying to contemplate some sort of electric heater... If there were a decent attachment point, seems like a 750watt heater would be feasible off the 12v... Or am I asking too much with all of the other 12v accessories likely running at the same time in the winter? And even then there's the question of where/how exactly one would set this heater to be useful and safe...

I was really hoping those electric heaters in the heating system would do more, but I can't even tell they're doing anything at all... Is there a fuse or something I can check with a voltmeter to confirm that they are coming on? And if so, is there a temperature limit to when they come on? (i.e. would they come on if I tried defrost right now with 70F outside temps?)

Thanks!
Levi

[bwilson4web]

I'd suggest getting at least volume 2 of the NHW11 maintenance manual. This will show you all of the systems and improve your luck diagnosing what is going on. Kudos for thinking of your heater before the winter returns.

Several thinks pop to mind:

• bleeding air from the heater core - I can envision trapped air making it less effective. How to bleed it, I don't know.
• heater coolant pump - located above the transaxle, the inverter has to move to reach it. This circulates coolant when the engine is off so don't rule it out.

Again, kudos for looking at the problem now instead of the dead of winter.

Bob Wilson