Faulty Heater

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Mad Maz
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Hi Guys

Wishing everyone a HAPPY NEW YEAR

Ive got an issue with my heater, the blower works fine on all settings.My problem is it only blows cold, as you can imagine not the best this time of year. Am i right in thinking its the matrix and if so is it as big as a job as it looks

Cheers Maz   

Mad Maz
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Re: Faulty Heater

Sorry guys the inportant bit 1993 W463 300gd

Jdring
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Re: Faulty Heater
You can disconnect the heater matrix in the engine bay and try to flush it but don't expect a miracle if it is blocked solid. You can try to back flush with a jet wash attachment and hope not to split any of the matrix! You may need to remove and/or replace in the end and that does mean the whole dash out. Easily a full day (I only did it myself once, it was enough). If you take the dash out, consider doing the wiper spindles too unless they are mint. Also, isn't there a valve to stop flow to the matrix... Make sure that is open and working.
JASONGDS
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Re: Faulty Heater

Check has enough water in it?

If you remove the carpet kick panel you can see hoses or put a hand on them to see if they are warm, it could be cable isn't connected?  Access is tight.

If you do remove , take lots of photos, seats have to come out  I expect it's a minor fault 

Mad Maz
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Re: Faulty Heater

Thanks Gents for the information fingers crossed it not a dash out repair

Pistonhead
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Re: Faulty Heater

If your heater knob setting has been set in the cold position all summer season then it may be the heater valve seals internally have bonded in the closed position cutting off hot water flow to the matrix.

Check the hose when hot at and before the valve if that part is hot and cold from the valve body onwards it is very likely the seals have bonded on. The valve is under the driver side centre consol. If posssible when the engine cools down, disconnect the inlet to the valve and space allowing blow some air into the valve to see if the seals blow off the internal lip. Connect and test.

If not leave the heater setting on the hot position for a few weeks to see if it unbonds otherwise it may mean full removal of valve and perervre or replace with a new one.

My best suggestion here is never fully set the heater knob in either the hot or cold position, in fact when you have bottomed out in either setting come back a bit so that the internal seals are never under full contact with the lip thus prventing such restrictions.

Happy New tear to you all

JASONGDS
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Re: Faulty Heater

What does the auxiliary electric pump do on the water side?  Does this effect heater circulation? 

Pistonhead
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Re: Faulty Heater

Also known as a duo-valve, it is merely there to assist for better water circulation in th coolant/heater system and avoid traped potential any air pockets.