Not enough heat

[Anonymous-0]

I have a 2000 Chev silverado with a 6 litre engine. The problem I'm having is that the heater doesn't blow really hot like it used to. Sometimes it's OK but on a not particularly cold day I should be able to roast in the cab. Anyone else had this problem? I'm wondering if I should get the cooling system flushed and/or a new thermostat. The temp. gauge shows normal like it always has. just under 100 deg. C. Any help would be appreciated. I removed the cab air filter to get more air flow but heat is the problem now. Thanks in advance. Dave

 

[RobMD]

I know on SOME vehicles there is a vacuum diaphragm valve in which lets the heated fluid pass through when you turn the heater. It will stop flow when the heat setting has been met.

HOWEVER, on the newer 1998-up vehicles, i would assume these proportioning valves are electronic.
Check along your heater hoses for this valve. Chances are it is plugged up. You may need to replace the heater hoses as well.

 

[msb]

Sounds like you need to clean the heater core. If you operate in in dusty, dirty conditions, it may need to be blown out with compressed air.Very common on old grain trucks as bees wings seem to have a way of plugging the core pretty good. Also had an old International that mice built a nest in the heater.Nearly froze before I got that cleaned out.

 

[noncompos]

"...sometimes it"s OK..." If you meant it sometimes works as it should, and other times doesn"t, that sounds like maybe something rotted partly loose inside one of the hoses, sometimes reducing water flow thru the heater core and sometimes not...if the temp is normal, and heat output always limited, that"s reduced flow thru the heater core. Check the heat adjustment switch/knob to see if it"s fully opening for hot water flow; probably next cheapest is thermostat and new heater hoses to see if helps. Or you might check some Chev sites for low heat or no heat posts to see if some kind of known problem. Good luck.

 

[Steven f/AZ]

Had the same problem with my Accord... Turns out there is a vacuum operated valve in the heater hose that was sticking. Loosened it up and haven't had a problem yet.

I'm not sure how the Chevy works, but sounds to me like you have either a sticking valve or heater box door.

 

[Lee in Iowa]

My 93 chevy wasn't making enough heat. We took the heater hoses off and flushed a lot of crud out with a garden hose annd then it worked much better. Lee

 

[Old Ford Mechanic]

Take your heater hoses off the heater core and flush it out with a garden hose.Then follow the directions on a bottle of raditor flush and do the rest of the cooling system.While your at it change the thermostat and fill with "new antifreeze".you will then have plenty of heat.Coolant should be changed every couple of years.

 

[Leland]

when was the last time you changed and flushed the cooling system ? that dex cool coolant will turn to jelly and start plugging things up is it time for a complete flush ?