Rep Power: 0

There is an inadequate heating/ventilation on my Honda Civic (2004 model) ever since I purchased. The temperature gauge does not reach more than 1/4 of its scale. The maximum heater's temperature gets just warm after about 30 minutes. I suspected a faulty thermostat (stuck in an open condition) but the thermostat appears to be in perfect working order. It was found in closed position in cold condition. I have tested it by immersing in a pan of hot water. It opened as it was immersed in hot water. It is rated as 78 degree C. I thought it was for summer use and it should have been higher rating for winter months. I am unable to get a higher rated thermostat.
Is this common problem with this particular model? If not, then any help or advice from fellow forum members would be appreciated.

 
Rep Power: 811

get a honda thermostat only. i had an aftermarket version that would close fully, but only open a little bit in boiling water. also check your coolant levels. you may have a clogged heater core or even easier, clogged cabin air filters behind the glove box.

 
Rep Power: 367

that's the first 04 6th generation civic i ever seen

 
Rep Power: 285

Like Gearbox said, start with checking to make sure you have a Honda thermostat and check you coolant. Often problems with the heating system can be solved just by changing the coolant, its often neglected.

 
Rep Power: 0

Thanks to all of you showing an interest in resolving my problem. I have replaced the thermostat bought from Honda, new one is rated 78 degree C same as the old one. I have drained and filled up with the fresh coolant but it has not made any difference.The temperature gauge still indicates about a quarter of the scale. I expect it to rise to half initially and settled between half and third of the scale as an average temperature. What do you think?
I do not think any blockage in the system is a cause of the problem as there is no sign of overheating. As the coolant does not heat up enough, the fan heater does not produce warm enough air for demisting therefore it takes longer to clear the screen. It demist quicker with AC turned on.

 
Rep Power: 811

can you post a pic of the temp gauge? it will never reach 1/2 on these cars. always a bit below that. you may also have a bad temp switch meaning you turn it to hot but it thinks it is still set to cold. if you turn it completely to the cold setting, does the air temp stay the same? have you checked behind the glove box to see if you feel warmth? thats where the heater core is and you should feel heat if the coolant is moving thru it.

 
Rep Power: 308

Also, you may want to check the valve in the middle of the firewall of the engine bay (look for the blue covered cable) Make sure the valve is moving to max when the temp control is full heat setting.

 
Rep Power: 0

Hi, following your instructions I have turned the temp control **** fully anti-clockwise to cold setting. The warm air turned to cold and the temp gauge arose to about half after about 3-4 minutes and then settled at about just over quarter of the full scale.
I have checked flow of coolant through core heater(a small radiator)behind glove box and below dash. The hoses carrying inlet and outlet flow found warm enough to hold the hose with bare hand. The only thing I want replacing the thermostat again to eliminate any doubt about its defectiveness. Although it is found closed in cold condition and opened as it was immersed in a pan of boiling water but its precise operating temperature is unknown. It may be opening up below 78 deg C.
The heat control valve diverting flow of coolant to core heater is functioning satisfactorily.
I shall keep you posted about any progress.

 
Rep Power: 811

that is a bigger problem if the temp gauge went up when you turned the dial to cold. either thermostat isnt working properly or there is a clog in the system (radiator or cooling passage). or the water pump is old and not circulating coolant properly.

 
Rep Power: 0

Thanks to all the fellow mwmbers who expressed their opinions to help me in resolving the problem. I would like to let all of you know that problem is resolved by replacing the pollen filter!
The cloggged up filter was restricting the intake of the blower fan.

 
Rep Power: 313

Sweet... that pollen filter is a dirty little rascal

 
Rep Power: 811

im running without them and get a ton more airflow.

 
Rep Power: 313

Not a bad idea especially considering them summabitches go for like 25 dollars here in Canada for the pair. You honestly have to replace them once every 3 months or they get clogged up.