Hi again,

             Is the heater monovalve insert the copper thermostat-like valve with 2 intakes on 1 side, 1 on top and one outlet to the manifold? It seems to not work. We removed it and placed water through it and it did not go through all inlets/outlets - one did not operate. Now, it seems dysfunctional because one goes to a solenoid controlled valve, with 4 screws to open - but - the outlets on this were cold, as if being not fed, but the top metal housing was screaming hot, so we assumed the valve was getting necessary electric supply but no antifreeze? . We removed that valve and placed direct power (jumped from the battery) and it did open. It worked. When looking on the internet, we see repair kits available but this copper valve with the 4 inlets/outlets is one piece and definitely not repairable. It is spring controlled like a thermostat, and when shaken when cold it makes a rattling noise. Any suggestions here please?

             Best regards,

                                     Tony Pike   J    J  

 My monovalve went bad some years ago, and the MB dealer put a 'repair kit' into it. Check with the parts dept at your Benz dealer.

 John