OK So as I previously mentioned the heater the Fiesta I just bought is temperamental, anyway today I had the bonnet open and to my surprise the tank was empty. I looked inside and there was just enough water in there so that it filled the pipes.Now it seems odd that the previous owner had not picked up on this, or the garage who inspected the car. Either the coolant has been neglected way too long or there a serious leak.

I just put some water in there from the water filter in the kitchen and drove the super market and bought a bottle of universal 5 year anti freeze and some deionised water. I put in about half the 1lr bottle of anti freeze and added some deionsed water until it was to the max. And then I had to do some urban waiting in traffic and going up hills for about 15 minutes and by the time I got there the water was very hot and very orange.
This panicked me at first but as far as I could tell it was from rust specs, there does not appear to be any oil in the water or water in the oil, the oil in fact looks immaculate, no "mayonnaise".
Should I just do a flush and add fresh anti freeze and add Radweld?

 

They normally have orangey/red anti freeze in them anyway.

Does the temp gauge stay within the normal range, cooling fan operating when sat running for prolonged periods?

Has it lost coolant since?

 

The temperature gauge goes to the middle after about 10 minutes of running stays there.

 

I spoke to the mechanic at the local garage, he does not sound to concerned, although I forgot to mention the heater (which still only works intermittently) however there has been no discernible loss in coolant since Thursday.

 

hi mate
you need to flush out your rad and header tank and all other water pipes at the same time
as there could be a air block in the system once done refill with clean water and a 50/50 mix of antifreeze as for your temp sitting half way that's normal nothing to worry about