I have a 1990 W124 230CE, and apart from all its minor faults, the one which may force me to sell it is that the heater is not working - i have read previous threads about duo valves in the past, however i know that this isn't the problem, because.......
Even when i disconnect the duo valve the 2 pipes are v.hot, the pump before the duo is working fine too, the pipe the other side of the matrix is very hot also, yet when i turn the blower unit on (which is also working fine) i get lots and lots of ice cold air. this has left me one or two possible theories.
The reason for the ice cold air is that the heater unit is opening the flap for external air (ice cold) but not for the heater, i guess it does this partly for temp control alongside the duo valve. I've found the flap for external air as it is in the passenger footwell by the bulkhead. Where is the flap controlling heat from the matrix? If i manually close the external flap (with my hand) and turn the blower on full, nothing comes out at all yet the blower is doing overtime in the process trying to force air out, even though all vents are open, , suggesting a second flap for the matrix?
1. Can i access the flap for hot air coming off the matrix (without taking the dashboard apart)
2. if so, where is it ( i read a similar thread which suggested it may be behind the radio, is this correct?
Someone also mentioned a back flush of the matrix, which may work, but i don't think this is the problem in this case.
For a quick fix i don't care about cold air, i can turn the blower unit off, and have sunroof / e/w for the summer
any help will be greatly appreciated otherwise its going on ebay in the new year
and i love it too much to give it up
snowdmc
Even when i disconnect the duo valve the 2 pipes are v.hot, the pump before the duo is working fine too, the pipe the other side of the matrix is very hot also, yet when i turn the blower unit on (which is also working fine) i get lots and lots of ice cold air. this has left me one or two possible theories.
The reason for the ice cold air is that the heater unit is opening the flap for external air (ice cold) but not for the heater, i guess it does this partly for temp control alongside the duo valve. I've found the flap for external air as it is in the passenger footwell by the bulkhead. Where is the flap controlling heat from the matrix? If i manually close the external flap (with my hand) and turn the blower on full, nothing comes out at all yet the blower is doing overtime in the process trying to force air out, even though all vents are open, , suggesting a second flap for the matrix?
1. Can i access the flap for hot air coming off the matrix (without taking the dashboard apart)
2. if so, where is it ( i read a similar thread which suggested it may be behind the radio, is this correct?
Someone also mentioned a back flush of the matrix, which may work, but i don't think this is the problem in this case.
For a quick fix i don't care about cold air, i can turn the blower unit off, and have sunroof / e/w for the summer
any help will be greatly appreciated otherwise its going on ebay in the new year
and i love it too much to give it upsnowdmc
