Honda Car Forum

My 1998 civic heater seems to be blocked somewhere. If I have the heater on
cold, then the flow of air is good, but if I have it on fully hot, then the
flow is very low.

I am running with the control set to just below max temperature to get some
heat out with some flow of air.

I have changed the pollen filter, but this has not improved things much.

Any ideas please.

Paul wrote:
> My 1998 civic heater seems to be blocked somewhere. If I have the heater on
> cold, then the flow of air is good, but if I have it on fully hot, then the
> flow is very low.
>
> I am running with the control set to just below max temperature to get some
> heat out with some flow of air.
>
> I have changed the pollen filter, but this has not improved things much.
>
> Any ideas please.
>
>
air flow on full hot is not as high since air's having to blow through
the heater matrix. if the air's not getting hot enough, check your
coolant level [inside the radiator, not the expansion bottle] and make
sure the coolant flow valve is operating properly.

"jim beam" <spamvortex@bad.example.net> wrote in message
news:EoWdneTx25JVz1fYnZ2dnUVZ_qzinZ2d@speakeasy.ne t...
air flow on full hot is not as high since air's having to blow through
the heater matrix. if the air's not getting hot enough, check your
coolant level [inside the radiator, not the expansion bottle] and make
sure the coolant flow valve is operating properly.



The air is hot enough, its the air flow which reduces, when directed through
the matrix I guess suggesting the matrix is blocked or something similar.
The fan noise rises significantly suggesting that something is blocked too.
How much of the dashboard do I have to dismantle to get to check this out?

Paul wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:EoWdneTx25JVz1fYnZ2dnUVZ_qzinZ2d@speakeasy.ne t...
> air flow on full hot is not as high since air's having to blow through
> the heater matrix. if the air's not getting hot enough, check your
> coolant level [inside the radiator, not the expansion bottle] and make
> sure the coolant flow valve is operating properly.
>
>
>
> The air is hot enough, its the air flow which reduces, when directed through
> the matrix I guess suggesting the matrix is blocked or something similar.
> The fan noise rises significantly suggesting that something is blocked too.
> How much of the dashboard do I have to dismantle to get to check this out?
>
>
you can get an exploratory hand in by taking out the glove box and
removing the duct that goes between the fan and the heater core. gets
more complicated if you have a/c installed though. to get at the core
completely requires removal of most of the dash.

"jim beam" <spamvortex@bad.example.net> wrote in message
news:qoidnfYNuuuYs1bYnZ2dnUVZ_s-rnZ2d@speakeasy.net...
Paul wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:EoWdneTx25JVz1fYnZ2dnUVZ_qzinZ2d@speakeasy.ne t...
> air flow on full hot is not as high since air's having to blow through
> the heater matrix. if the air's not getting hot enough, check your
> coolant level [inside the radiator, not the expansion bottle] and make
> sure the coolant flow valve is operating properly.
>
>
>
> The air is hot enough, its the air flow which reduces, when directed
> through the matrix I guess suggesting the matrix is blocked or something
> similar.
> The fan noise rises significantly suggesting that something is blocked
> too.
> How much of the dashboard do I have to dismantle to get to check this out?
>
you can get an exploratory hand in by taking out the glove box and
removing the duct that goes between the fan and the heater core. gets
more complicated if you have a/c installed though. to get at the core
completely requires removal of most of the dash.

I have got aircon (which I suspect is out of gass), Is there any online pics
of this anywhere you are aware of?

Paul wrote:
> you can get an exploratory hand in by taking out the glove box and
> removing the duct that goes between the fan and the heater core. gets
> more complicated if you have a/c installed though. to get at the core
> completely requires removal of most of the dash.
>
> I have got aircon (which I suspect is out of gass), Is there any online pics
> of this anywhere you are aware of?

==============================
Diagrams at www.slhondaparts.com Find the 'remove the stereo' sites to
learn how to pop the panels off. Sometimes the 'change the cabin
filters' page will help depending on the model.

Where the heck is _the duct that goes between the fan and the heater
core_ ?? Sounds like you're describing the frame of the cabin filter
(newer models).

'Curly'