Could anyone advise on how the hot/cold, sliding switch, on a 190 Masterace, operates ? Does it open or close a water valve, directly or, via a solenoid, or, does it operate an air flap which directs or diverts, air over the heater matrix ? On my vehicle, the change from hot to cold can, sometimes, just not operate and, usually, remains in the "hot" mode. Sometimes, over a matter of, say, an hours driving, it will go from hot to cold but, never in the usually required way, ie, in a minute or two. I have tried all variations of settings, ie, fresh air and re-circulating and with the air con on and off, with no marked effect. I feel that a sensor might be sticking and taking it's time to re-act to the required setting. This is only with the front controls. The rear heater/cool air blower, seems to work as required. Could anyone kindly comment or throw any light on this problem ? Thanks - (#2418) John Davis, 6 Mar 02

John
Not sure if the Townie has the same heating system as the Model F which uses control cables to work a water valve and air dampers. I have to say that the heater controls on mine are very smooth which tells me that it is more likely to be electrically operated as I don't appear to be tugging at cables - but could be wrong. Trouble is, heaters are always a pain to get to but if you start to dismantle it check for cables and if there, ensure they are not broken or binding. Check for leaking or clogged heater hoses and check for faulty water valve.
HTH
Ian - (#2421) Ian Dunse, 6 Mar 02

Depending on trim level, it could be cables to a valve and a flap, or an electronically controlled system. The water valve is under the front floor, BTW - (#2423) david miller, 6 Mar 02