Poor heating in the NX - Anyone else experience this?

[Deathstar]

Dear all,

After getting rid of my beloved IS250, I have bought my 2018 NX. After four months of ownership this is the first cold snap we have had. Although on the test drive I thought the Air Con was not as Powerful as my IS (which was awesome) I put this down to just being a different car. The heating system is also 'weak'. The heated seats get lovely and warm, however the heater, doesn't really blow out piping warm air. 

My daily commute is only 15-20 minutes, but in that time, the car does get up to temperature quickly, however setting the temperature to 25 still renders luke warm air. I have turned off the rear vents using 's flow' and made sure I am in Normal driving mode rather than 'Eco' but these don't seem to do anything. Am I missing any other setting somewhere? The heated seats and steering wheel are lovely, with the seats being much warmer than the IS, its just the heating system feels underpowered for the size of car. 

[royoftherovers]

45 minutes ago, Dylanlewis2000 said:

Dear all,

After getting rid of my beloved IS250, I have bought my 2018 NX. After four months of ownership this is the first cold snap we have had. Although on the test drive I thought the Air Con was not as Powerful as my IS (which was awesome) I put this down to just being a different car. The heating system is also 'weak'. The heated seats get lovely and warm, however the heater, doesn't really blow out piping warm air. 

My daily commute is only 15-20 minutes, but in that time, the car does get up to temperature quickly, however setting the temperature to 25 still renders luke warm air. I have turned off the rear vents using 's flow' and made sure I am in Normal driving mode rather than 'Eco' but these don't seem to do anything. Am I missing any other setting somewhere? The heated seats and steering wheel are lovely, with the seats being much warmer than the IS, its just the heating system feels underpowered for the size of car. 

Take it back to the Dealer who sold it to you immediately as he remains responsible for fixing problems occurring within 6 months of purchase.

[Deathstar]

@royoftherovers easier said than done. The dealer is 200 miles away, my nearest dealer is 50 miles, i've already been in once this month with the dodgey sensors 😪

 

I was just wondering if this is an 'NX' thing.

[royoftherovers]

1 hour ago, Dylanlewis2000 said:

@royoftherovers easier said than done. The dealer is 200 miles away, my nearest dealer is 50 miles, i've already been in once this month with the dodgey sensors 😪

 

I was just wondering if this is an 'NX' thing.

OK Dylan, thanks for letting me know.

The distance does not however absolve the Dealer from his responsibilities. Is your local Lexus Dealer paying for any remedial work ?

We`ve plenty of NX Members and I `ve not noticed a plethora of complaints similar to yours.

Is the Dealer you bought from accepting his responsibilities or have you not informed him ?.

[DanD]

I don't think this is necessary a problem and I would say it is working as designed, based on my experience of 2 NX and 2 RX before that. I believe the set up only allows air to be pumped into the car only once it has reached the desired temperature, regardless of the temperature you set. In fact, by setting the temperature to 25, you most probably delay the process. Furthermore, if left in 'auto' mode, the warm air is directed to the footwells and not the air vents on the dash, which means that it is not immediately noticeable. You will also notice that the airflow automatically switches to 'recycle' mode until the car has reached the desired temperature to prevent cold air being pumped in.

I used to have a 45-60 minute commute, during which the car used to warm up nicely. Like you, my commute is now 15 minutes and I am experiencing the same 'issue', thankfully mitigated by the heated seat and heated steering wheel.

My advice would be to override the 'auto' control, increasing fan speed and manually redirecting the airflow to where you want it to go.

[Deathstar]

3 minutes ago, DanD said:

I don't think this is necessary a problem and I would say it is working as designed, based on my experience of 2 NX and 2 RX before that. I believe the set up only allows air to be pumped into the car only once it has reached the desired temperature, regardless of the temperature you set. In fact, by setting the temperature to 25, you most probably delay the process. Furthermore, if left in 'auto' mode, the warm air is directed to the footwells and not the air vents on the dash, which means that it is not immediately noticeable. You will also notice that the airflow automatically switches to 'recycle' mode until the car has reached the desired temperature to prevent cold air being pumped in.

I used to have a 45-60 minute commute, during which the car used to warm up nicely. Like you, my commute is now 15 minutes and I am experiencing the same 'issue', thankfully mitigated by the heated seat and heated steering wheel.

My advice would be to override the 'auto' control, increasing fan speed and manually redirecting the airflow to where you want it to go.

@royoftherovers I haven't informed them, I was just wondering what others thought about it. 

My IS250 was different, so I was just wondering what experience people had.

 

@DanD - It's interesting you are finding that. I have turned the mode to manual as I find the car mists up, therefore I have the windscreen and footwell mode on. 

[paulrnx]

Make sure you have the following items set.

efficient ventilation set to OFF

set climate control to NORMAL or FAST. Don’t have it set to SLOW.

Then see if these make any difference 

[NemesisUK]

2 hours ago, Dylanlewis2000 said:

@royoftherovers I haven't informed them, I was just wondering what others thought about it. 

My IS250 was different, so I was just wondering what experience people had.

 

@DanD - It's interesting you are finding that. I have turned the mode to manual as I find the car mists up, therefore I have the windscreen and footwell mode on. 

Do you have the a/c set to On? With this working the cabin air will be dehumidified. Only caveat is that at ambient temps approaching freezing the a/c will not operate, for fear of the condenser freezing. IIRC the cut-off temp is 5c

[paulrnx]

Oh and always use AUTO with the temperature set to say 25 on both sides of the car, ie not in DUAL mode.

This should be enough to force warm air out of the vents in an effort to auto-maintain the cabin temperature at 25.

If this doesn’t work, set the temperature both sides to max, set the flow control to the face level vents position and crank the fan speed up to check that: (1) The air coming out of the vents gets hot. (2) The fans blow faster. (3) The flaps controlling the air distribution inside the system are working.

if you can’t force hot air out after a 15 minute journey, something is wrong. If you can force hot air out by taking manual control but still no hot air in Auto, something is also wrong.

[Thackeray]

8 hours ago, Dylanlewis2000 said:

My daily commute is only 15-20 minutes, but in that time, the car does get up to temperature quickly

Just to be clear, did you mean to write "the car does get up to temperature quickly" or did you mean the car is slow to get up to temperature?

If the cabin has reached the set temperature you probably won't get warm air from the face vents. On the IS300h it will gently blow warm air from the face vents initially while the car is warming up. But it pretty soon switches to cool air as soon as the cabin has warmed up.

[Steve Oliver]

Yes, not everyone understands climate control (but I don't think that's the OP's issue here?)... the temperature you set on the "dial" is the temperature you want the car to be, not the temperature you want coming out of the vents....

[Deathstar]

Hi all, 
Thank you for your responses. I took a few photos today but they all came out blury! More tomorrow I think. 

@Thackeray - What I mean is that the temperature gauge for the engine gets up to temperature (middle of the gauge) fairly quickly. 

This morning the outside temperature was 0, and on the way home it was 11. It did feel a little warmer in the cabin, but i'm not sure if that was just me. 

The main reason I'm asking is that I have read on some of the newer cars (especially electric) the heat pump heaters are not that great in the depths of winter, in that they don't go anywhere near as hot as a conventional engine radiator would, therefore I was wondering if this was the same for the hybrid system. My first IS250 was awesome, it would heat up quickly and If I put it up anywhere close to 23, it was like having a furnace on the go. My wife's Tiguan is the same, when set at 24 the air coming out of the vents is very hot. 

There's only four settings in the climate control:

• Dual - SET TO OFF
• A/C - SET TO OFF
• S Flow - SET TO ON (I thought this would pull more heat to the front)
• Polen Filter - SET TO OFF

[Don C]

The engine will cut in if the heater can’t get to the desired temperature.  Lexus go to a lot of trouble to stop you nodding off which avoids a lot of warm air around your head so it does hold back a bit.  The system is quick to warm up but then it starts to mix fresh air in.  I’ll have a fiddle with mine and see if I can get a setting which gives some meaningful comparisons.   

[Deathstar]

Great thank you.

[paulrnx]

This should be simple. Leave climate control in Auto. If you feel too cold, turn the temperature up. If you feel too hot, turn the temperature down.

[Thackeray]

10 hours ago, Dylanlewis2000 said:

What I mean is that the temperature gauge for the engine gets up to temperature (middle of the gauge) fairly quickly.

So is the problem that the cabin is cold? Or is the cabin temperature ok but you'd prefer to have warm air coming from the face vents?

What happens when you turn on the windscreen demister after the engine has warmed up - do you get warm air onto the windscreen?

 

[Deathstar]

14 minutes ago, Thackeray said:

So is the problem that the cabin is cold? Or is the cabin temperature ok but you'd prefer to have warm air coming from the face vents?

What happens when you turn on the windscreen demister after the engine has warmed up - do you get warm air onto the windscreen?

 

Issue is the cabin is cold, the air coming out of the vents isn't particularly warm. 

[Thackeray]

1 hour ago, Dylanlewis2000 said:

Issue is the cabin is cold, the air coming out of the vents isn't particularly warm.

Well, that sounds like a fault. Just to double check, it's zero degrees outside, you start up the cold car, you use Normal mode rather than ECO, you press Auto on the climate control and select a temperature (say, 23 degrees). No other buttons are pressed after this. After a 20 minute drive, the cabin is still only, say,  10 degrees.

If I did this in the IS300h, there would initially be little air flow. But after about five minutes (or maybe longer in cold weather) the engine is warm enough to supply warm air to the cabin and the fans start to turn faster to heat the cabin. Then when the cabin is warm the fans slow down again and cool air comes from the  face vents.

If you can use the free Hybrid Assistant app, it will show you what the cabin temperature sensor is reading, along with the outside temperature, and the engine temperature.

On the other hand, a simpler test when you're driving the car is to ask yourself, "Can I take my coat off?" If the answer is "No," then your heating is not working properly.

I'm not familiar with the NX but cold cars were phased out in the 1950s, even though the first heaters were optional extras. So I doubt the absence of warmth is a new feature for the NX.

[Don C]

I got the engine up to temperature and then ran it a good few minutes to make sure the bulk temperature of the engine and whatever other components that get hot did do.  The outside temperature is 6C.  I put the transmission in sport so i could see the rpm and set the heater to max on both sides and the direction from the face vents  as shown - AC on.  Full throttle produced 2500 rpm and after 90 seconds the temperature at the vent was hot to the touch.   I must say that when I let my foot off, the engine shut down and and the temperature quickly fell to warm.   It’s not very scientific but I measured the temperature at the vent at the hottest as shown too.  

[Thackeray]

.

 

[Thackeray]

14 hours ago, Dylanlewis2000 said:

The main reason I'm asking is that I have read on some of the newer cars (especially electric) the heat pump heaters are not that great in the depths of winter, in that they don't go anywhere near as hot as a conventional engine radiator would, therefore I was wondering if this was the same for the hybrid system.

Lexus/Toyota hybrid cars have a petrol engine like conventional cars, which provides the heat for the cabin via the engine coolant. Purely electric cars don't have this source of heat, so they have to provide some other means of heating the cabin. The original Volkswagen beetle had the same problem as its Porsche designed rear-mounted engine was air cooled. Can't remember how they solved the problem but I seem to recall that the heating wasn't very effective.

The key question for Dylan is what temperature the cabin reaches. Does it stick at, say, 10 degrees or does it go up to around 20?

[Deathstar]

1 hour ago, Don C said:

I got the engine up to temperature and then ran it a good few minutes to make sure the bulk temperature of the engine and whatever other components that get hot did do.  The outside temperature is 6C.  I put the transmission in sport so i could see the rpm and set the heater to max on both sides and the direction from the face vents  as shown - AC on.  Full throttle produced 2500 rpm and after 90 seconds the temperature at the vent was hot to the touch.   I must say that when I let my foot off, the engine shut down and and the temperature quickly fell to warm.   It’s not very scientific but I measured the temperature at the vent at the hottest as shown too.  

I will do the same later - thank you for this!

[Don C]

1 hour ago, Thackeray said:

Lexus/Toyota hybrid cars have a petrol engine like conventional cars, which provides the heat for the cabin via the engine coolant. Purely electric cars don't have this source of heat, so they have to provide some other means of heating the cabin. The original Volkswagen beetle had the same problem as its Porsche designed rear-mounted engine was air cooled. Can't remember how they solved the problem but I seem to recall that the heating wasn't very effective.

The key question for Dylan is what temperature the cabin reaches. Does it stick at, say, 10 degrees or does it go up to around 20?

The VWs had a heat exchanger surrounding the exhaust.   
 

What you’ve got to watch with measuring straight forward interior temperature is the effect of ambient temperature, sunshine, interior materials and how much moisture they hold and then how long you leave it until you measure it.   It’s going to be a bit Heath Robinson to test any way other than fully instrumenting the car under strict laboratory conditions.   My gut feeling is, there’s nothing different to Dylan’s car to most of ours.  

[DanD]

@Dylanlewis2000 Make sure that a/c is switched on (to prevent misting up/condensation) and that there is no more than 2-3 degrees difference between left and right.

Do you, by any chance, have the panoramic roof? My current NX has the pan roof, and so did the previous one, and I found that it is easier to maintain a warmer temperature if the blind is fully closed on cold days.

[Deathstar]

Well, this is very strange. The display temperature outside said 10^oC. I cranked the heating up to Hi and set it to blow out taking a reading after a few minutes and this was the result:

 

It seems that it is warm, although she was in EV mode, it had only just knocked off just before I took the photo. I suppose all is well, I just need to run it on HI.