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heater issues!

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mike vas

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nuneaton
Car
accord
i have the accord executive with the climate control. its really annoying that passenger side temp works perfect hot or cold but drivers side just cold.
anyone else had this issue and is it a simple fix?????? its the diesel model too if that helps
 
Might be sensors as it have dual climate control.Try to do diagnostic.For these problems HONDA HDS scanner could show problems They cost £80 pounds but will save your time.;)
 
Sorry, I will use the topic to ask for more details about extra heating system of diesel Accords described in User guide:
Your vehicle has the hot gas heater system. It ***ists the heater until the engine warms up after you start the engine. This system uses your vehicle's air conditioning system to warm the air. Under the following conditions, the hot gas heater system operates automatically.

• The engine coolant is cold (under about 75° C).
• The outside temperature is low (under about 5° C).
• Any temperature except for the maximum cool can be set with the driver's side temperature control dial.
• The fan is set to the desired speed.

After the engine warms up or the outside temperature is high, the hot gas heater system will stop automatically.
You may hear some noise from the engine compartment. This is normal; it is the hot gas heater activation.
The hot gas heater system will not activate if the outside temperature is too cold (under -35°C).

It's a bit confusing saying- "gas heater system" and "system uses your vehicle's air conditioning system"

Does somebody know what that system is, and how it works? How to test/use it?
Unfortunately recently no temperatures below 5deg to test it.
 
it runs the system in reverse

i.e. heat comes out of the evaporator

this reversible system is only in the diesel-engined car, because the diesel engine takes a long time to warm up.
 
freddofrog said:
it runs the system in reverse

i.e. heat comes out of the evaporator

this reversible system is only in the diesel-engined car, because the diesel engine takes a long time to warm up.
Click to expand...
OK but why description says gas heater system if it uses just AC system?
Anyway how to test/use it? Is it fully automatic, e.g. when temperature is below 5deg just need to turn on AUTO, or need to control manually fan speed and to turn on AC?
 
That's a good question, but I suppose the answer comes down to "semantics".

An "air-conditioning" system is just a big refrigerator, but whereas a refrigerator cools a closed well-insulated and air-tight box, an "air-conditioning" system attempts to cool a large ventilated space. But they are both the same thing.

However, they are also a "heat-pump", and a "heat-pump" is a system that transfers heat from one place to another. In doing this, a "heat-pump" has a point where heat is "absorbed" (hence cooling the space around that point) and a point where heat is "expelled" (hence heating the space around that point). Note that "heat" is anything above zero Kelvin (-273 C). So a heat-pump can be used to draw "excess" heat from the ground into a house i.e. a "refrigerator" in reverse, which cools the ground and heats the house (note that the ground in say Alaska, even at -50C, is still Kelvin warm, so it can be cooled further).

In other words, heat-pump = refrigerator, heat-pump = heater, refrigerator = heater .....but those systems all use "refrigerant gas" in the piping, which is hot at the point where heat is expelled from the system.

Just put "heat pump" into google images and you'll find loads of images, such as this one ....

2731_001(2).jpg




In the above picture, in normal operation the A/C in the car expels heat on the left-hand side at the "condenser", where the heat is lost directly in the air-stream.

In the diesel-engined Accord, when outside temperatures are cold and the engine is cold, there is a valve that changes the arrangement of the piping in the system, such that heat is now expelled in the cabin, and heat is absorbed outside of the cabin (i.e. cool gas circulates through a point in the outside air). I can only ***ume that the heat is expelled at the evaporator, and that heat is absorbed at the condenser. But someone may one day take a diesel-engined Accord apart and discover that there is a heat exchanger in the water-matrix, and/or there is a small evaporator hidden somewhere in the engine compartment.

Finally, if you want to test the system in your car, drive up to Finland, but make sure that you fill the fuel-tank with winter-diesel on the way, otherwise the diesel fuel will freeze LOL
 
Good explanation of heat pump principle but I know it. Just wanted to know if this is a case or it is something different been confused of above mentioned descriptions.
Instead Finland, I hope there will be at least one frosty day his winter for test... :)
 
If you compare the piping in the diesel-engined Accord with that in a petrol-engined Accord, it is a much simpler layout in the latter.

If you read through "diagnosing aircon problems" that I started in May 2012, I was puzzled when I saw the radical difference on the diesel (didn't see a diesel layout until #15) http://typeaccord.co.uk/forum/topic/10382-diagnosing-aircon-problems/

When a "diesel heater" system was mentioned a year ago, fortunately I was already aware of the reason for the difference http://typeaccord.co.uk/forum/topic/18746-rattly-noise-when-cold/

If you do a search in the forum, you will see that it was previously mentioned in November 2010 (before I was a forum member) and briefly described as a heat pump by someone, see #76 to #84 in this thread http://typeaccord.co.uk/forum/topic/1483-cool-features-you-never-knew-you-had/?p=18472

Note that the valve is visible down in front of the condenser and AFAIK it has never given any problems, although the "****ogue" pressure sensor next to it does give problems.

If you do get a chance to test it, it would be very interesting to see and hear it in operation :)
 
freddofrog said:
If you do get a chance to test it, it would be very interesting to see and hear it in operation :)
Click to expand...
Now is cold enough but I can't feel any worm air coming from vents. After start the engine I tried to push Auto or Windscreen buttons. Both ways no worm air.
Few months ago I topped up AC system (when cold blowing was just from passenger side) but now I am not sure if in the system there is enough gas.
At todays outside temperature (-4deg), temperature gauge even didn't move from start position until I got to work (3.7 miles). Few months ago I changed thermostat. Do I need to use manual controls for AC+fan speed on the display?
Initially when I push Auto button, the fan speed is very low, after two miles air blowing gets a little bit wormer and fan speed increases slightly. I don't know if this is normal.
 
I'm sure it works in Auto mode, and the reason the fan speed is being changed is because the system is waiting for enough heat. If you put fan speed to high onto a cold system it might never warm up.

I reckon that there isn't enough gas, you can get it pressure tested.
 
freddofrog said:
I reckon that there isn't enough gas, you can get it pressure tested.
Click to expand...
Yes it is possible...Probably I am not right person to test that feature. Let's somebody else share information how system works.
Anyway generally I am not happy with heating system at all. I never had a car with so bad heating. Even when engine is fully wormed and use manual control- AC is Off, any fan speed, I never can get hot air blowing... I can feel worm blowing no more then 40 deg. (cooling fluid should be about 80 deg) There is no way to get hot air like many other cars I had.
So I am not sure if Accord heating is weak or my car had a problem.
 
You ought to check the temperature of the coolant before ***uming that there is a fault or lack of heating capability in the main heater.

When I wrote #7 I didn't realise that I'd already mentioned "heat pump" in another thread http://typeaccord.co.uk/forum/topic/14575-heater-problems/?p=216549 and that it was yourself at that point in that thread LOL

Best thing is to go into the diagnostic mode and check the coolant temperature

here are the instructions again

SEA3E50K71100000000BBAT00_4.jpg



If the coolant is 79 and the blower still feels cold, remove the pollen filter and see if that helps (the glove box can be swung down for the pollen filer to be pulled out)

Also check the position of the valve that lets coolant into the heater matrix.

valve fully open ....

IMAG0555__zps0f8598e7.jpg



valve fully closed .....


IMAG0556__zpsffadb3f7.jpg



the valve should not be in any other position.



Basically, if the coolant is at 79 C (in the diagnostic), and if the pollen filter is removed, and if the valve is definitely in the fully open position, and if the blower is still not blowing hot, then the heater matrix is partially blocked.
 
When I find free time I will make diagnosis again (if you remember, I did it few times in the summer about cooling problems...)
Where is the valve on the pictures, I've never seen it before? What/how control that valve?
I suppose you could be right about:
"and if the blower is still not blowing hot, then the heater matrix is partially blocked."
 
If you lift the bonnet up, you'll see it near the top of the engine bay (below the rubber seal for the bonnet, which you can see in the pictures).

The valve is opened and closed automatically. In this cold weather you can "force" the system into closing the valve by setting both the target temperatures to LO (the system will then shut off the coolant to the heater matrix, so that it can make the cabin as cold as possible). The system will open the valve when either target temperature is sufficient for the system to need to get heat into the cabin. In hot weather, you would have to have one of the target temperatures set to HI.
 
I found the valve, it is open. Will check if it moves,
Soon I'll do diagnostic to see what is the real coolant temperature.
 
After 25 miles journey I did some tests and diagnostic:
1. I set target temperatures to Lo, the valve was closed. Then I set target to 21deg, valve was open, so it works.
2. Under diagnostic mode results are:
Sensors:
1 - 23
2 - 13
3 - 08
4 - 78
5 - 03
6 - 59
7 - 58
8 - 00
9 - 36
10-07
Sensor 10 should be A/C pressure.
 
Those readings look perfect (btw it looks like you did not have A/C OFF and it was also dark)

Next time you've driven that sort of distance, run the diagnostic again and see if you get similar readings (presumably you still had target temperatures set to 21).

Then put the target temperatures to HI and take the readings again.

If the heater is not blowing hot with target temperatures set to HI (and with pollen filter removed) then you might have a partially blocked heater matrix.
 
freddofrog said:
Then put the target temperatures to HI and take the readings again.

If the heater is not blowing hot with target temperatures set to HI (and with pollen filter removed) then you might have a partially blocked heater matrix.
Click to expand...
I will do it at the weekend.
Why do you think it was dark? It was cloudy.
Should the A/C be ON when AUTO is ON with 21 targets?
Just now realized I am not sure when I had readings if AUTO was activated, if fan was working...or everything was OFF...
I think when I hold both buttons and start the engine (to start the diagnostic), the AUTO remains ON.
When I make suggested new test, do I live AUTU ON, or should be manual control (AC OFF, face blowing vents and highest fan speed ) ?
 
When you go into the diagnostic mode, IIRC it goes into Auto if Auto was On, or Manual mode if it was previously in that mode.

If it was in Auto you can leave it like that, or you can actually go into Manual mode while the diagnostics are showing. But once you've put it into Manual mode, you can't go back to Auto, because pressing Auto will turn the diagnostic off.
 
I did the test again at target 21deg and got the same readings. The weather was rainy and I didn't remove the pollen filter.
Then I set target to Hi and manual control- Max fan speed, AC OFF, face blow vents:
1 - 22
2 - 12
3 - 03
4 - 77
5 - 14
6 - 99
7 - 99
8 - 00
9 - 65
10-05
The blowing air was quite hot and I think system i working good.
Just wonder in Auto mode why AC switches ON/OFF intermittent (target temperature been reached , fan speed was very low and I can hear compressor)
 
Yeah that sounds ok, no blocked heater matrix then :)

When Auto is ON, the system is in "climate control" mode, which means that as well as maintaining the target temperature, it wants to reduce moisture in the air. It uses the evaporator to do that.

Put simply, A/C is always on with system in Auto mode, even if the engine is cold, outside temperature is say 8C, and target temperature is say 24C.

For that reason I always turn A/C off, unless
1. there is a build up of moisture on the windows
2. the outside is hot and I want to cool the inside

Note that you can leave it in Auto mode but just turn the A/C off.
 
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