Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

  • When you purchase through links on our site, we may earn an affiliate commission. Read more here.


hiya. i think my heater matrix is knackered as i only get warm air coming out.. but i find if my expansion bottle is in between full and minimum rather than up full, it does seem to get hotter..

any ideas?

or is it just my matrix?

sounds like the little knob on the dash(or the mechinism) that dictates hot or cold air is knakered! if it was your matrix then water would be pi**ing everywhere!

sorry my name aint bob but thought i say something!
  clio 20v

it can get blocked too, it might just be airlocked and not having a full expansion tank is letting some of the air out

strip off the pipes and connect a hosepipe to it and flush it through, draining and filling should get rid of any airlocks too

  Clio II 1.4 Priveleg

Bob RTE to the rescue!

Sounds to me like the heater matrix may be partially blocked.

Does the temperature gauge read between 1/4 and 1/2 when warmed up?

Does the radiator cooling fan cut in when idling and hot?

Do BOTH the hoses to the heater get hot? or just one of them?

Answers on a postcard to the usual forum.


PS: if you turn the little knobby thingy on the heater control panel to cold, does the heater get colder? - if so, its not the little knobby thingy.

PPS: The expansion bottle serves 3 purposes.

1. To allow for the expansion of the coolant when it gets hot.

2. A cap to maintain or release excessive pressure

3. It de-gasses the cooling system (self bleeding)

Hope that helps.

ok bob. yes between 1/4 and 1/2 then up when sitting in traffic - all fine

yep fan works

both hoses?? where explain?? - think so

knob works fine

and i have bled the system already
  Clio II 1.4 Priveleg

There are 2 hoses to the heater matrix.

They are located on the baulkhead just behind the gearbox/engine split. They are about midway up the baulkhead.

One will be very hot and the other cold if the matrix IS BLOCKED.

Try that and let me know.