Flushing out a heater matrix.

[KarlT]

Winter has arrived & my heater matrix is at least half blocked.
New cost £135
Anyone managed to flush/clear theirs?
How, What chemicals did you use?

[CJH]

I did mine out of the vehicle when I replaced the heater box, so it was fairly easy to hook it up to a hose pipe (via a larger diameter hose) and blast it through with mains pressure water. I didn't use any chemicals - didn't think to. It only took a moment for the water to run clear.

In the vehicle it'll obviously be more of a challenge to connect a hose pipe, but I would have thought mains pressure water would be enough to flush it fairly well.

[KarlT]

Sounds worth ago then, did you notice big difference?
I was thinking drain unblocker or something.

[lloydy]

you could use central heating cleaner?

[CJH]

I wasn't aware of a decrease in output from mine beforehand - it just seemed like a good opportunity to flush it out while it was out of the van. I think domestic drain unblockers aim to clear a sink waste of grease mostly, which won't be the main problem in a heater matrix. Fine sludge would be the main problem I think, so flushing it (both ways) with a hose ought to clean it out. Or use central heating cleaner as lloydy says.

I did my entire cooling system with a hosepipe before I changed my coolant a couple of years ago, and got very wet feet that day! Where are you planning to break into the heater pipework? I can't remember - is it continuous all the way to the engine bay?

[KarlT]

Yeah Lloyd that sounds better,
I want to replace blower as well, squeaky/rattily thing. So I'm guessing that means dash out......... scared!!
I'm planning on putting in a rear heater too....... I can see this job growing!!!
Any good writes up on this?

[CJH]

Not so much a 'write up', more some personal experiences: https://club8090.co.uk/forum/viewtopic.php?f=37&t=148054" onclick="window.open(this.href);return false;

Getting the dash out isn't as daunting as it's made out to be. One tip I'd share though - if you've got an impact driver it'll help with the four large crosshead bolts at the outer ends of the dash, and even the small philips screws along the edge below the screen. All of these can be a bit corroded, and the impact driver gets them out without chewing up the heads - use it BEFORE chewing up the heads with a normal screwdriver. My impact driver is fast becoming one of my favourite tools!

[kevtherev]

I would have thought it was easier to flush from the engine bay.

[Mocki]

is this not a technical question.....
its pretty damn simple to find the tech section...... dont worry ill do it....

[Dazco]

If you do use a hose pipe from the mains be very very careful.
I replaced my heater matrix a couple of years back and decided to flush the old one through to see what crud came out.
With the hosepipe on and running through the matrix i covered the outlet a bit. The increase in pressure popped the heater matrix, it was scrap anyway so didn't matter. Be warned.