Heater not working

[littlescrote]

Picking up from a different thread, is it possible to programme the MMCS to turn off heating?

Huh? It's possible to program in a timed session (start at hh:mm for x minutes, where x = 10, 20 or 30), but that's all. Meant for pre-heat, pre-demist or pre-cool.

 

[greendwarf]

Ok - back here in steerage with our "no electric heater or MMCS" Gx3Hs we are ignorant of these technical wonders - and the frustrations they cause :lol:

One further thought about cold air after a while - does it happen when ICE is running? - as it could be the valve in the engine cooling system jammed shut stopping circulation through the heater matrix. :idea:

 

[kromo]

yes, it happens when ICE is on

 

[greendwarf]

My thinking is, that in general, the car tries to conserve the battery at all times. So it would be logical for the electric heating to cut out once the engine coolant has reached normal temperature because it will expect coolant will start circulating through the heater matrix but if the valve that controls this is jammed shut then all you get is cold air!

More worryingly this will happen if the coolant level is too low! How do you know there is a radiator leak in an ICE car ? When the heater blows out cold air suddenly. So there could be a more serious problem if the ICE cooling is not effective.

 

[Piotr]

Hi, I'm new on the forum. I'm using 2014 Phev and after two months of using the car I saw that heating system stops working, blower works fine but with outdoor temperature only. I afraid that it could be a serious damage but I focus on collecting useful information from web. I found on few forums that sometimes problem is caused by inline filter in pipes coming to cabine (aluminium one with deaerator) . I visited my favourite workshop and asked to check it. They cleaned inline filter and heat exchanger . Heating works fine now. Hope it help somebody. It was not expensive repair.

Based on information that water pump has a few power gears it could impact heating in the car in case of lower power delivered to the pamp when temperature in cabine is almost stable . In this case flow of liquid could be limited and heating would not work effectively. Please let know if it solve your problem.

 

[mali]

Hi,

Help!!

I am new to this forum. In September 2018, I bought an Outlander (GX4H 2015 UK model) and in Dec noticed there is bare minimum of heat coming through. Took it to dealer who said heater matrix valve blocked and after flushing it kinda worked but never gave real heat ie when you put it to 29 degrees it just blows warm air. I've lived with it until now where it just blows cold air full stop. Took it to main dealer and after diagnostic, they said - needs PTC Heater, Heater Matrix, 2x AC pipe sills and gass, Needs in-line coolant filter, el;ectric water pump, 4 way valve- all this for a mere sum of only £5,000 - dealers think money grows on trees!
I was told by the mechanic this is a common problem with Outlanders. I am at a loss and would really appreciate any help or guidance fromk anyone on this forum.

Monsur

 

[ThudnBlundr]

Have a look at Section Q in Richi's excellent FAQs: https://www.richi.uk/p/mitsubishi-outlander-phev-faq.html#phevfaqQ

 

[kromo]

My thinking is, that in general, the car tries to conserve the battery at all times. So it would be logical for the electric heating to cut out once the engine coolant has reached normal temperature because it will expect coolant will start circulating through the heater matrix but if the valve that controls this is jammed shut then all you get is cold air!

More worryingly this will happen if the coolant level is too low! How do you know there is a radiator leak in an ICE car ? When the heater blows out cold air suddenly. So there could be a more serious problem if the ICE cooling is not effective.

the problem was with the 4-way valve

 

[jasonhiggins]

I resolved my heater problem!
I followed the instructions to remove the 4 way valve housing) and cleaned the thermostatic valve. It worked only for a short time. It seems that mine was clogged/damaged inside the thermostatic valve itself - there was a lot of black "muck" but it felt slightly rubbery.
After 3 removals I decided that cleaning was not the answer.
I removed it all again a 4th time and re-engineered the valve and... it worked! That is not to say that I recommend the solution but I have never been so pleased to have hot air blowing through the vents again.
So, this is what I have learned.
- The electric heating which lasts for a few minutes of driving if you have low/no battery charge was always working just fine.
- After this time, the cabin fans continued to run but the air was cold regardless of air conditioning on/off.
- As described by many, the 4 way valve is the source of the problem. The thermostatic valve (inside the housing) is more complicated than most switches as there are 2 valves in one which directs the coolant flow from heater matrix to air-con (and loops the motor coolant directly back by return) OR, when the engine is hot, from engine to air-con (which I *think* still passes over the heater matrix but I'm not sure).
- The problem my car had sounds quite common for the gx4h which is that the valve gets "stuck" and the coolant simply loops back to the engine without mixing back to the air-con. Once the heater matrix switches off, cabin heat is cold.
Holding the valve casing upside down with one pipe top left and three to the right, we need to close the lower internal vent but keep the upper vent open (is "seizes" closed which causes the no-heat issue). This way, we are leaving the unit in engine heating mode.
For reference, top right is flow in, top left is flow out (to air-con) with lower right outflow to engine and middle right is input from the engine.
I removed the larger spring, reversed the thermostatic valve and added the holding plate at the top to allow free fluid flow through the upper vent.
I'll add video/pics if it's useful.

 

[nrayanov]

Thank you for sharing your experience, and the solution to your heater problem with the community, and for helping to contribute to the knowledge base.

It's interesting to see the various issues that can arise and it's helpful for other users to have this information so they can be aware of potential issues and how to fix them.

If you have any additional information, including pictures or videos, that you would like to share, we would greatly appreciate it. These can often help to provide a more complete picture of the problem and the solution, and they may be helpful to other users who may be experiencing similar issues.

 

[littlescrote]

Hi,

Help!!

I am new to this forum. In September 2018, I bought an Outlander (GX4H 2015 UK model) and in Dec noticed there is bare minimum of heat coming through. Took it to dealer who said heater matrix valve blocked and after flushing it kinda worked but never gave real heat ie when you put it to 29 degrees it just blows warm air. I've lived with it until now where it just blows cold air full stop. Took it to main dealer and after diagnostic, they said - needs PTC Heater, Heater Matrix, 2x AC pipe sills and gass, Needs in-line coolant filter, el;ectric water pump, 4 way valve- all this for a mere sum of only £5,000 - dealers think money grows on trees!
I was told by the mechanic this is a common problem with Outlanders. I am at a loss and would really appreciate any help or guidance fromk anyone on this forum.

Monsur

Cheeky sods - it's a manufacturing fault that causes it to be blocked in the first place!

 

[vanlinks99]

I have exact issue with 2018 phev. Dealer flushed out the filter which worked for 11 days and now same issue back again.

Is there a permanent fix for this?

 

[jyveborg]

I resolved my heater problem!
I followed the instructions to remove the 4 way valve housing) and cleaned the thermostatic valve. It worked only for a short time. It seems that mine was clogged/damaged inside the thermostatic valve itself - there was a lot of black "muck" but it felt slightly rubbery.
After 3 removals I decided that cleaning was not the answer.
I removed it all again a 4th time and re-engineered the valve and... it worked! That is not to say that I recommend the solution but I have never been so pleased to have hot air blowing through the vents again.
So, this is what I have learned.
- The electric heating which lasts for a few minutes of driving if you have low/no battery charge was always working just fine.
- After this time, the cabin fans continued to run but the air was cold regardless of air conditioning on/off.
- As described by many, the 4 way valve is the source of the problem. The thermostatic valve (inside the housing) is more complicated than most switches as there are 2 valves in one which directs the coolant flow from heater matrix to air-con (and loops the motor coolant directly back by return) OR, when the engine is hot, from engine to air-con (which I *think* still passes over the heater matrix but I'm not sure).
- The problem my car had sounds quite common for the gx4h which is that the valve gets "stuck" and the coolant simply loops back to the engine without mixing back to the air-con. Once the heater matrix switches off, cabin heat is cold.
Holding the valve casing upside down with one pipe top left and three to the right, we need to close the lower internal vent but keep the upper vent open (is "seizes" closed which causes the no-heat issue). This way, we are leaving the unit in engine heating mode.
For reference, top right is flow in, top left is flow out (to air-con) with lower right outflow to engine and middle right is input from the engine.
I removed the larger spring, reversed the thermostatic valve and added the holding plate at the top to allow free fluid flow through the upper vent.
I'll add video/pics if it's useful.

Do you have any more info on how you put the valve togeher this way? Can't make it work without the big spring...

 

[Asac]

Do you have any more info on how you put the valve togeher this way? Can't make it work without the big spring...

I have a 2018 PHEV. Drove it an hour with no heat . 17 degrees. From one Mitsubishi dealership. Which had it for 9 days and 400 bucks later . Had no idea. Now at second dealership for no heat. Flushed, new aux pump. Cleaned filter. No luck. Dealer is contacting Mitsubishi directly. Will keep posted. In Cleveland Ohio area. Dealerships have left. Next one is two hours away. Ughh

 

[jyveborg]

I think I got the valve put together in a way so that is is always open - no change though and lines to cabin heater is still cold. Something must be blocking the coolant in that circuit from circulating. Will connect a few temp hoses (transparent) to try and pinpoint where the issue is. Might even bypass the pump and electric heater completely and go straight to the cabin heater.