Heater Defroster doesn't get Hot

Radiator, thermostat, water pump, antifreeze, etc.
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Topic author
cfs
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Heater Defroster doesn't get Hot

Post by cfs »

has anyone replaced a heater control valve yet ? My 2002 Astro doesn't get hot ?any ideas ? Radiator is full and water pump and Intake Gasket are brand new.
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doyoulikeithere
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Re: Heater Defroster doesn't get Hot

Post by doyoulikeithere »

Question:
with the engine running: If you move the selector from 'COLD (blue)', to , 'hot (red)', can you actually hear the vacuum actuated door that directs the air, can you hear it move at all?
Reason for question: If the heater is heating, but the door isnt opening to allow the heat to get to the outlets, you will need to fix the vacuum leak that keeps your heater control from operating.
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1987 Astro - With 5 Speed & 4wd - Silver & Blue.

LiftedAWDAstro
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Re: Heater Defroster doesn't get Hot

Post by LiftedAWDAstro »

You can check the 2 heater hoses that go into the box on the firewall on the passenger side. Theses 2 coolant hoses go to the heater core. If they are hot when selected for heat then the issue is not the control valve. There is a thread here someplace where one of the members replaced his control valve.
Current rides:
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2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

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Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
cfs
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I am merely driving my van
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Re: Heater Defroster doesn't get Hot

Post by cfs »

Thank you for the tips and comments
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LiftedAWDAstro
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Re: Heater Defroster doesn't get Hot

Post by LiftedAWDAstro »

Great looking van! I love it!
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
cfs
I am merely driving my van
I am merely driving my van
Posts: 19
Joined: Wed Oct 27, 2010 7:31 am

Re: Heater Defroster doesn't get Hot

Post by cfs »

She's a 2002 Explorer Limited edition AWD High Top. Explorer Vans has been fantastic about factory replacement parts -122k miles on the clock.

trevcda
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Re: Heater Defroster doesn't get Hot

Post by trevcda »

I hope you don't mind if I piggy back your thread; my questions are along the same lines.

I've got a 98 Safari. As it's been getting colder I've noticed that the heat/defrost gets warm but not really hot. I believe that the heater control valve is working fine, the engine just doesn't get that hot. The thermostat in the dash get a little above 100 but not much. Normally a cool running engine is a good thing. Is there something available that partially obstructs the radiator and could raise the temp a few degrees?

LiftedAWDAstro
I have my van tatooed on my cheeks
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Location: New Haven, NY

Re: Heater Defroster doesn't get Hot

Post by LiftedAWDAstro »

I would see about replacing the thermostat. These 4.3's generate lots of heat so you most likely have a stuck open thermostat. What I used to do with my old cars was place a piece of cardboard in front of part of the radiator.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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HPbyStan
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Re: Heater Defroster doesn't get Hot

Post by HPbyStan »

The heater hose fitting coming from the intake manifold is restricted down to a tiny opening and buying one with a larger hole or drilling out yours lets more hot water get to the heater instead of going directly to the engine radiator.
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