Loosing coolant on daily basis but no signs of a leak. Did have a loose heater hose which eventually came off completely and emptied coolant. However hose repaired and coolant replaced plus pressure tested and no leaks found (tested cold). Still loosing coolant and also heater now only works every now and then. No contamination to oil. Only mild concentrate of antifreeze present recently but water seems to be pumping through rad. I was thinking possible head gasket leaking at rear of engine to cause the leak and frozen bottom end of radiator to cause heater problems. Also thermostat may not be working correctly as temperature remained very low on motorway travel and stayed at 12 o'clock for town driving. However since the cold spell stays at 12 o'clock so possible input of stronger antifreeze solution loosened up the thermostat especially as colour of coolant turned reddish. Any help appreciated.
Heaters don't work right when low on coolant have it pressure tested hot not cold. If you don't see any leaks outside then it's more than likely internal and will have to be torn down to find it. Also check radiator for cold spots when engine up to temp if it has cold spots the rad needsto be replaced. When you do htis make usre engine is off an dfans if electric are disconnected sothey won't start.