Heating fails

xantian · Unread post by **xantian** » 24 Oct 2004, 22:44

I have a Xantia 1.8 Dimension 1995, No a/c. Recently the heating fails intermittently. Not hot air coming out. I use different setting on the control, eg, recirculate, blow to foot, to windscreen, etc. but no joy. I waited long enough with the engine running. I can see the temp has rosed to nearly 100 degree celsius. Still no hot air

Could anyone give some advise on this? could it a blown fuse?
thanks

AndersDK · Unread post by **AndersDK** » 24 Oct 2004, 23:40

It couild be the ignition switch that has burnt out - unfortunately a common problem on Ph1 Xantia.
Try fiddle with the ignition key switch while you have the problem. If you then can get the blower on at short moments - you have found the problem.
If you do a search on heater blower - you'll get loads on this problem.

PeterMann · Unread post by **PeterMann** » 25 Oct 2004, 05:57

If you email me at [email protected] , I will send a parcel of information, including circuit diagram for a modification which fixes the problem and photos.

xantian · Unread post by **xantian** » 25 Oct 2004, 06:14

Thanks for the reply. Just want to clarify the problem. There is air coming out from the vent. And it's working on different "speed", ie, the higher the speed (number) the stronger the wind. Only thing is it's cold, not warm.

RichardR · Unread post by **RichardR** » 25 Oct 2004, 20:27

I'm not sure what temperature you'd expect the engine to run at, but if 100 degrees is high then that coupled with the intermittent failure of the heater would suggest a possible air lock to me.
I'm not familiar with the layout of that engine, but the general way to deal with an airlock would be to turn the heating on full, take the cap of the radiator or header tank (not just the expansion tank) and then run the engine. As it warms up, keep an eye on the water level in the radiator and top it up as necessary. What you'd hopefully see if some bubbling from the radiator as the air is expelled from the system. You can also check the temperature of the various water pipes to monitor for any cold spots, and also try giving them a squeeze to get the water circulating. You should then allow the engine to cool down and repeat the cycle as many times as necessary until the heater's working correctly, the temperature gauge is reading correctly, the fan is cutting in at the right point and the water level in the radiator is steady. Then top up the expansion tank as necessary and replace all caps.
As previously stated, these instructions are fairly generic, so if anyone has any more specific information for this particular engine that should take precedence.

xantian · Unread post by **xantian** » 27 Oct 2004, 04:05

thanks Richard,
I'll try it tomorrow. Btw, can anybody tell me where is the header tank? cheers

jeremy · Unread post by **jeremy** » 28 Oct 2004, 00:24

I'm not familiar with the Xantia setup but from the sound of it either the heater element is blocked or (mor likely) one of the control flaps has become detached. BX have a water valve to control the temperature but ZX does not and relies on flaps to divert the hot air away from the passenger compartment when its not required. Assuming a design progression I would expect the xantia to be an air blender like the Zx and there to be a flap which cuts off the heat altogether.
As a first step I would find the feed and return pipes to the heater element and see if they are getting hot quite quickly. If they are not then find out why. You could flush the element and its hoses witha garden hose to see if there is a water flow. the element could be blocked or alternatively one of the hoses may have collapsed blocking it.
If the water side of things is ok then time to investigate all that wonderful linkage nicely concealed behind the dash.
jeremy

harryb.48 · Unread post by **harryb.48** » 28 Oct 2004, 04:10

As Richard says , its possibly an air lock.
I have the same model Xantia and the top of the "header tank" is actually lower than some of the hoses and in fact is just at the side of the radiator in the Xantia.
You have to fill a bottle or suchlike and turn it upside down on the radiator cap,effectively making your own header tank, to make sure all levels are reached,whilst opening the bleed screws on top of radiator,thermostat housing and on top of the heater hose just above and behind the thermostat,in that order.
Its best to run the engine and add the water/coolant until all air bubbles disappear.
If that doesn`t cure the air lock ,then try putting a garden hose into the heater hose and flushing the heater matrix out(not too high a pressure)then bleeding again. - I fixed my friend`s car just last week with this procedure ,it was a 106 but the layout is much the same and he had exactly the same symptoms.
Regards

xantian · Unread post by **xantian** » 30 Oct 2004, 22:15

I have bled the system today. Still no hot air. I'll repeat what I have done today.
I opened the cap of the expansion tank (just next to the radiator), I also opened 2 bleed screws (one at thermostat housing and another one on top of the hose, just like harryb.48 described), but I couldn't find the one on top of radiator mentioned by harryb.48. I can hear air coming out from the bleed screws. but it wasn't too bad, the air stopped after about 3 seconds. the one on the termostat housing is better, can't hear any air coming out.
Then I run the engine, I can see the bubbles appearing in the expansion tank. I closed the bleed screws after water emerged from them. The fan starts operating at about 92 deg. And stops at about 90 deg. I guess that means it tries to maintain the temp at 90 deg. Is it ok?
I didn't notice when the termostat starts open the valve. The last time I touched the hose when it was cold, it was less than 80 deg.
And the first time I felt the hose is warm, that was certainly before the fan started. So I would guess the termostat opens at about 85 deg. Again, is this ok?
The bubbles disappeared eventually after a while. but still no luck

I think I gonna try the flushing method that you suggest. harryb.48 or someone, can you tell me where should the water goes in and out. Could you also give some more details if possible. Sorry for the long post, and thanks again.

beezer · Unread post by **beezer** » 30 Oct 2004, 23:58

You should see two hoses entering the bulkhead. The one that connects with the waterpump should be the outlet. Try reverse flushing through this hose.

xantian · Unread post by **xantian** » 02 Nov 2004, 06:50

Strangely today, when i run the engine again before trying to do the flushing thing. The heater works again. Hooray! i don't whether this is the due to the bleeding work i have done earlier. anyway who cares now

but i think it is more likely to be the fault from the flap, the one that control the temperature. Maybe its loose or something like that.

wrinklet1 · Unread post by **wrinklet1** » 02 Nov 2004, 12:55

Hi,
Your heater matrix is blocked up I'm afraid. If it wasnt, you would get some warm air at least coming from one or two vents.
The matrix is a very poor design in the Xantia, it is vertical rather them horizontal, and it has onlt a fed in and out at the sa,e point, therefore it gets filled with crud over the years and blocks up. Even flushing wont help because of its design.
The only way to get around it is to replace the matrix, I did it on my Xantia, started at 10am, job done for 6pm, you need a haynes manual and some long sockets to get at some nuts in the bulkhead.
Hard job, but worthwhile doing.
Paul

xantian · Unread post by **xantian** » 03 Nov 2004, 03:03

How much does it cost for a new or used matrix?
Do I need to strip the dash down to change it? I hope not..

jeremy · Unread post by **jeremy** » 03 Nov 2004, 04:31

Looks as though the matrix is listed in the new GSF catalogue (download available on the main site) at £29.50 +VAT.
I'm sure you have to take the dash out. Lovely job - did it twice on my Renault 21 - not that bad if you are methodical and careful.
As a suggestion when you've got all the heater apart clean it thoroughly and wash any areas that have been soaked with cooling water and anti-freeze - it will make it smell nicer when you've finished.
jeremy

wrinklet1 · Unread post by **wrinklet1** » 03 Nov 2004, 13:53

Yes, I agree with Jeremy.
You do have to remove the whole dashboard to do the job. Make sure you get a new set of O rings for the heater hose to matrix connection otherwise you will end up loosing all your coolant.
<u></u>Dont <u></u>get a used matrix as it is false economy, and as I said before, make sure you have some long reach sockets as you will need them for the bulkead bolt that holds the dash to the bodywork .
It is also worthwhile getting a mixture of clips and cable ties because once the dash is out you will see things either snapped or that have come undone.
Good Luck and as Spock said to Kirk 'Live long and prosper'
Paul