Cold heaters... brrrr

[Rod1-gti]

Hi guys, Im having a problem with my heaters, they always blow cold, on the odd occasion they'll warm up to luke warm but not for long. I have bled the system and as far as i can tell there is no airlocks.

It doesnt over heat (unless my guage reads wrong), the pipes to the heater matrix get hot so i assume the thermostat is ok as it seems to be letting water in.

Please help, my car is sooo cold. 

[Wayne]

Well if the pipes to the matrix are warm then it sounds like the matrix is blocked.

[Len]

They shouldnt be just warm! Too hot to touch!
Does sound like a blockage somewhere though!

[Rod1-gti]

I'll try bleeding and flushing it again. if the matrix is blocked will it just be case of flushing through with a hosepipe?

[javalin]

worth a try I think.

[Gal]

One thing to try if you can ( can on a vaux frontera ) is add some iron/kettle cleaning fluid/crushed tablet into the matrix. Add hot water and block the other end and leave over night. Then flush out with water one way, then back flush till clear water comes out. Refit hoses and slowly top up water with anti freeze leaving engine running and heater son full and the setting to hot. Keep the cap off the expansion tank and then once full and up to temp close it. Take it for a run then check to see if the levels have gone down