Hello, the heater in my 2000 discovery is not working. When I turn the heat up full blast it blows cold air. The A/C works fine. I would appreciate any help with this problem or any tips on how to fix it. Thanks

 

first, check your coolant level

 

Yup, first sign of low coolant is no heat.

 

It is safe to say you have a coolant leak, do you know how to check, fill and bleed the air out of your coolant system?
I would suggest you do this before you over heat your engine and cause some costly damage.
If you don't know how to do this, PM me with your tele number and I will call you and walk you thru this.

 

I am having the same problem on 2003 Disco. Heater blowing cold air...checked coolant...no coolant.....currently in the shop doing pressure test etc. no visible leaks. Then I came across the post about the slushing water sound from within, under the dashboard that my disco has had for about a year. does this mean the coolant is leaking to a place within the vehicle and isf so from where to where. If anyone has any info I'd appreciate it.

 

Yes, go have your truck's coolant system pressure tested ASAP before you over heat the engine causing expensive repairs.

 

No it is not leaking into the car, the sloshing sound is the coolant moving through/around inside your heater core which is inside the dash, kinda behind the glove box and that is why you can hear it so well inside the cabin.
When the cooling system is properly filled and void of all air you cannot hear the coolant moving inside the heater core because there is no empty space.
As a good rule visually check your coolant level (the resevoiur is clear) once a week when you check your oil.
If it is below the "Full Cold" mark then top it off.
CHECK IT ONCE A WEEK WHEN YOU CHECK THE ENGINE OIL LEVEL

 

Reviving this because I'm experiencing the same thing but haven't managed to find a possible remedy. So here's what's up... Blower works great, A/C works great, flushed cooling system and replaced thermostat last week, coolant levels are perfect, system is properly bled and without leaks. Any other ideas?

 

Flush just the heater core.

 

Flush and then backflush the heater core.