V70R Heater

[Nev]

hi all,

my heater blows warm, not hot, to the windscreen.
If I change it to blow at the floor, or anywhere really, it only blows cold air.
I can hear everything moving and the air changes direction as it should, just no heat.

Any ideas welcome, its cold outside and I want to be warm inside.

[LeeT5]

(Might help if we knew what vehicle it is?)

Firstly check your coolant level in the expansion bottle is above minimum when cold but not above Maximum.

You're going to need an infrared thermo probe for the next bit as checking hoses with your hands is firstly unprofessional and secondly, not accurate, not to mention the risk of scalding yourself if something is/goes wrong!

Once the engine is up to temperature, Radiator fans kicking in/out as normal, A/C switched off, cabin air temp set to max but have the blower on medium and out the front vents.

With the thermoprobe; check the temperature on both the top and bottom hose on the Rad. It needs to be about 15*C cooler on whichever hose (depending on flow into the Rad) but essentially, the temperature will be circa 80-90*C.
If that's ok, then move on to the Heater matrix hoses on the bulkhead. You should have roughly the same temps as the Rad hoses but more importantly, you need to have about 10*C difference in temperature between the two hoses. Try to measure on the rubber hose, not any metal clips or plastic parts.

If that is OK, then the fault lies with the electronic flap control side of things, inside the dash. :worried: That won't be cheap to fix.

If the heater matrix hoses are massively different, ie, 87*C on one and 57*C on the other, for example, then you have a blocked Heater matrix.

It would be beneficial if you can check 'live readings' as to what the ECU is reading via the Temp sensor.

Another thing to check is; does the air coming out the vents get hot or hotter when you increase engine speed? If so, this is a good indication that the water pump is working, however, this should really be checked properly using a pressure gauge.

If you cannot be 100% on any of the above then you really should get it to a garage, in case you have a cooling issue.

Sorry but that's the best I can do. Faults surrounding cooling issues and heating really need proper diagnosing in a controlled environment with the correct equipment as a misdiagnosis could lead to engine damage or injury to person.
Vehicle cooling systems should be treated with the utmost care and not taken for granted.
I wouldn't want to ill advise you and then you do something or damage your engine. Get it properly checked mate ;)

[stribo]

It's a P2 V70R, judging by the fact it's in Phase 2 models, and it says V70R heater. :hilarious

[htomi]

In addition to Lee's comments above:

If you have access to VIDA, check if there is any CCM related DCT stored. If its error free, then complete the CCM recalibration too.

Next, clean the passenger compartment air temp sensor with a hoover as sometimes this gets clogged.
Make sure you're not going to touch or break the copper wire behind the went as then the CCM unit won't work anymore.

If you're handy enough, take out the CCM as you'd be able to get better access to the fan behind which should also rotate freely.


Does your car have the latest software update from Volvo? There is one available for the CCM module.

[LeeT5]

It's a P2 V70R, judging by the fact it's in Phase 2 models, and it says V70R heater. :hilarious

Point taken :smirk:

[LeeT5]

In addition to Lee's comments above:

If you have access to VIDA, check if there is any CCM related DCT stored. If its error free, then complete the CCM recalibration too.

Next, clean the passenger compartment air temp sensor with a hoover as sometimes this gets clogged.
Make sure you're not going to touch or break the copper wire behind the went as then the CCM unit won't work anymore.

If you're handy enough, take out the CCM as you'd be able to get better access to the fan behind which should also rotate freely.


Does your car have the latest software update from Volvo? There is one available for the CCM module.

You can use an Air duster spray into the tiny grille. This will blow the dust off the fan first. Then use a contact cleaner spray to clean any dirt off the sensor. Make sure you spray air duster first then contact cleaner (not the other way round).

[htomi]

When I got my car it was clogged.
I took out the CCM module, then carefully disassembled it.
Cleaned the fan + tube first and then used Photographic Solutions Eclipse (liquid cleaning solution to remove dust/dirt from a digital camera sensor) and a sensor swab to clean the copper wire. Took me aprox 45-50 mins from start to finish.
Obviously the compressed air/ air duster + contact spray should do the job too.

[ivor]

31409
Maybe it could bethe evaporator temp sensor