Just Bought A Used Prius As My First Car. A Few Questions...

[kithmo]

Is heat just not coming from the face vents or is it not coming from any ?

Doesn't appear to be coming from any.

If all the vents are blowing air, but no heat then it's got to be the heat flap that's stuck, I'll try and find out where it is and come back to you.

[kithmo]

Just searched on Priuschat the US forum and came across this. http://priuschat.com/threads/2006-prius-heater-flow-control-valve-question.150132/#post-2135368

it seems there's a valve (not a flap) that controls the direction of the coolant and it could be this at fault

[kissinger]

Thanks guys. I ended up going back and this time they did do a HHC, so you were right. Got an all clear too, which is great. They also found a fault with the heating this time. Apparently the water pump had a leak, which they're going to fix tomorrow for £273, which sounds reasonable to me, so I'm happy.

[kithmo]

There was a free fix on the hybrid coolant pump via a recall, check which pump it is.

[MEP's Yaris GS]

check which pump it is.

Sounds like the engine one if its affecting the heat output.

[kithmo]

check which pump it is.

Sounds like the engine one if its affecting the heat output.

agreed if the pump leak is the cause of the heat output loss

[kissinger]

Okay guys, sorry to dredge this thread up once again, but I'm still having major issues with my heating system. I did end up taking the car into my local Toyota dealer and they did carry out the repair to the coolant they identified, but I'm not at all sure the problem is really fixed.

When I got the car back the heating seemed to work fine, but the very first time I had to do an early morning commute the heating wouldn't seem to come on, at least until I got driving. I was sat in my car for about 10 minutes with both the heating and fans on max, with the front windshield demister on, and I was getting no hot air whatsoever. The only way I was eventually able to get going was by driving with severely restricted visibility (only to the end of my road), and as soon as I did that it seemed to work fine again. It was super dangerous though! I tried again today and the same thing happened (although thankfully the windows weren't misted when I set off this time).

Can I just confirm with some long-time Prius owners that this is not, in fact, normal and that the heating should work from a cold start straight away?

If that is the case, I suppose my next step is to get back in contact with the dealership, but I'm not sure what I'm entitled to for the money I've already paid. Just to recap, I've been to see them three times already. I paid for a full service and then for the the coolant pump repair, so I've spent around £500 on what should be a fairly minor repair. Am I being reasonable by asking them to complete the repair at no additional cost or can I expect to pay the hourly rate for however long it takes them to diagnose the real fault and for the additional parts (if any)?

[MEP's Yaris GS]

Well you're not going to get any heat until the car has either been driven, or sat with the ICE running for a good 5+min while sitting stationary.

Explain the exact procedure you go through to operate the ventilation system once you've started, what buttons do you press etc?

Regarding getting it fixed, you've paid for a service, you got a service. They identified a coolant leak which they've fixed and charged you for. I can't see why you'd be expecting them to resolve another potential issue FOC?

[PeteB]

Certainly when I drove a Gen 2 Prius, if I put it in READY mode (aka switched it on) on a frosty morning and put the Climate Control from all Auto to front screen demist mode leaving the fan on Auto (it will go to more or less max fan in auto mode anyway), the ice on the windscreen had normally melted by the time I'd scraped the side windows.

If it was just cold, setting off immediately and leaving Climate on full auto with the temperature set to 18C (my prefered setting) I got heat fairly quickly, certainly quite warm by the time I'd done a mile.

In fact, that's been true of all three generations of Prius I've owned/driven.

[kissinger]

Regarding getting it fixed, you've paid for a service, you got a service. They identified a coolant leak which they've fixed and charged you for. I can't see why you'd be expecting them to resolve another potential issue FOC?

Really? Come on. From my point of view as the consumer, I paid them to fix the radiator and it would seem as though they haven't done that. So although it might turn out that I will have to pay for other repairs to it, it's hardly a silly question for me to ask. Especially when you consider that a large part of the bill is for the man hours it took them to diagnose the fault.

But to answer your other question, the procedure I go through is to turn on the ignition, go into the 'Climate' menu, select 'HI' as the temperature (so that's over 30C), put the fans to max with heat blowing into my face. If I do that from a cold start I seem to get cold air only seemingly no matter how long I leave it. Part of what's been making me think it's broke is that I can hear the petrol engine start up when I turn on the heating, and yet I still only get cold air. But maybe I'm not leaving it long enough? Are there specific settings you're supposed to leave it on?

Based on what you and Pete have said though, it sounds like this is just how Priuses work: you don't get instant heat and the heating is only really effective when driving. If that's the case, then I can live with it. It's just that not having that much experience with these cars (or with driving full stop) it seemed like a fault. The only other car I've driven is an '04 Ford Focus, which basically turns into a sauna as soon as you put the heating and fans on max. Certainly when I was driving back from a 100 mile round trip just the other day the heating seemed to work very well, and I don't want to turn up at the dealership saying, 'it's broken', when it's not...

[PeteB]

Most cars need a little time for the engine to heat up the coolant water which in turn feeds the interior heater.

Some are quicker than others. The only cars I'm aware of that can produce almost instant heat are those with heat pumps (mostly EVs).

Alloy engines tend to heat faster - a Ford Fiesta I bought in 1980 with an all iron engine took 5 miles to fully warm up (thermostat opened) on anything but a very warm day - sadly my journey to work was 5 miles.

[timberwolf]

But to answer your other question, the procedure I go through is to turn on the ignition, go into the 'Climate' menu, select 'HI' as the temperature (so that's over 30C), put the fans to max with heat blowing into my face. If I do that from a cold start I seem to get cold air only seemingly no matter how long I leave it. Part of what's been making me think it's broke is that I can hear the petrol engine start up when I turn on the heating, and yet I still only get cold air. But maybe I'm not leaving it long enough? Are there specific settings you're supposed to leave it on?

Noted that Auto A/C was on (I always leave it on).

Desired temperature was 18.5C (I checked today but normally I just leave it from the last journey).

Windows were fogged, so I switched on front and rear demisters.

According to the car the outside air temperature was +3C. With the car running, I scrapped a thin layer of ice off the front, back and a tiny bit of the side windows. It has been about 5 minutes since starting the car when I set off, the front windscreen is still a little foggy but clearing, no real noticeable heat (but note that I never set the fan speed myself as in my experience that overrides part of the automatic system and switching on the front demister will adjust the fan speed to high automatically). Rear windscreen I think has ice or maybe excess moisture on the inside, and even six miles into my journey this has not cleared, although I didn't notice when the rear demister automatically switched off - btw the rear heater on mine has always been pathetically weak and the placement of the wires and the rear wiper arc have always imho seemed more suited to mainland Europe and not the UK.

I noticed some heat after maybe a mile or two of driving, but I can't recall if I checked the vents. I switched off the front demister as soon as the windscreen was fully clear as I dislike the high fan noise.

On the journey back the car was still warm enough that heat was available from setting off, front demister was required briefly, and the rear demister never fully cleared the rear windscreen, but I don't think I switched it on again until part way through the return leg. Outside air temperature had dropped to 2C, maybe the slight temperature drop was due to the sleet or just the car moving?

I don't know if that helps?

[Chris Dance]

If you are not satisfied with the work carried out by your dealer. Go back and tell them your concerns. I find Toyota dealers very helpful and want satisfied customers.

With regard to the heating system/demist etcI agree with others you need to drive to get it fully functional. All the Toyota cars I have owned mist up more than other makes of car I have owned and require air conditioning on to clear it. Select front screen to on etc as Pete suggests.

[PeteB]

I find the defrost button useful:

When you press it:

• if the fan speed is still set to auto, it adjusts it to a fairly high setting - if you've previously selected a fan speed manually, it keeps that speed
• if the circulation is set to recirc, it changes to fresh air to aid demisting
• if the A/C is off, it turns it on

When you press it again it puts everything back as it was, except if you manually selected a fan speed whilst in demist mode, it remains at that manually set speed until you press auto again.

Note that if you're in (driver selected) EV mode, pressing demist will cancel it so it can run the engine to make some heat.

The one extra thing I'd like is to have screen only as one of the options in the cycling of distribution choices, so that I could select screen only manually without killing EV mode when only slight demisting is needed and A/C with outside air would be sufficient.

[kithmo]

My old Gen 3 behaved in a similar manner, took ages to warm and only demisted the bottom half of the screen until you got moving.

Don't mess with the temperature and blower settings, it doesn't make it warm up any quicker, just set the temp to whatever you prefer (I usually had it set at 21) and put it on auto.

From cold, turn on the car, turn on the climate, you'll notice the blower does nothing at this stage, to boost it turn on windscreen and rear screen demist. After about 5-10 minutes it should start to produce heat and the screen should be mostly demisted.

Make sure you haven't got the car in ECO mode as this will restrict the heater performance for the sake of economy.

The engine will produce more heat if it is worked (driven) but driving off straight away is not always an option if your windows are steamed up, unless you wipe them.

[PeteB]

... ECO mode as this will restrict the heater performance for the sake of economy...

Does anyone know if ECO mode's effect on Heating & Ventilation is over-ridden when using the Demist button?

[MEP's Yaris GS]

... ECO mode as this will restrict the heater performance for the sake of economy...

Does anyone know if ECO mode's effect on Heating & Ventilation is over-ridden when using the Demist button?

I believe it is.

Personally to get the best from the system myself I always leave it in auto and just set the temp and let it do its own thing. Always have heat within about 3 miles of moving off.

[johalareewi]

With my gen3 prius, there is no heat to the cabin until the engine has warmed up. This can take a few minutes so rather than blow cold air around, I leave the fan off. If the front screen needs demisting, then I put that on.

[PeteB]

this morning was a good example when I went out - 1C on the display, all four tyres showing 0 or 1, ice on all windows (not too thick but bad enough). 20C selected as desired interior temperature, stayed in ECO mode.

Turned car on, hit front and rear demist buttons (engine started as soon as I pressed the front demist button without completing the normal 7 sec wait).

Scraped both sides, by which time rear window was almost clear, bottom third of ice on front screen had almost melted - scaped rest off, jumped in, low heat already from heater.

by the time I was a mile away the fan was slowing down, and a little condensation at the top of the screen (above my line of sight) had gone, switched back to normal auto and fairly hot air was coming out.

[MEP's Yaris GS]

this morning was a good example when I went out - 1C on the display, all four tyres showing 0 or 1, ice on all windows (not too thick but bad enough). 20C selected as desired interior temperature, stayed in ECO mode.

Turned car on, hit front and rear demist buttons (engine started as soon as I pressed the front demist button without completing the normal 7 sec wait).

Scraped both sides, by which time rear window was almost clear, bottom third of ice on front screen had almost melted - scaped rest off, jumped in, low heat already from heater.

by the time I was a mile away the fan was slowing down, and a little condensation at the top of the screen (above my line of sight) had gone, switched back to normal auto and fairly hot air was coming out.

Interesting. 1C at 0800 this morning for me. Luke Warm water over the front screen to clear it. Heated seat on max and EV'ed down to Hopton PO. Came out, fired up the ICE and set climate to 23.5C Auto.

Had fans firing up about half way along the A12 towards the JPH, and sat at the roundabout in Hopton for about a minute before being able to get out.