heater blowing cold air in ford escort zx2 1998?

my 1997 escort heater keeps blowing hot or cold air when the heaters are on

tair
December 2007

i think either the element has gone in the heating system or you should have your cylinder head gasket checked is it using more water than usual?

stephen
October 2006

Find either the temp sender or the fan sender switch. They are normally on the thermostat housing. With the engine cold remove whitch ever one is highest. Now run the engine and see if any air bubbles pop out of the hole. Try revving the engine while you do this. If no air pops out try flushing the matrix. Remove the two pipes that run thru the bulkhead, put a hose on the bottom one and run plenty of water thru it. If none of this works you can try a new thermostat but only do this if the engine temp and not just the matrix is running either to hot or cold.

Simon.
October 2005