S2 Heater

[alcooker]

Hi Guys,

I wonder if anyone can diagnose the following:-

Had the car up to temperature and ticking over today, heater mechanism has had a week being freed up with WD40 so I can actually move the lever to hot. When I turned the heater fan on full it kicked good warm air out for about 10 seconds, then went very slightly warmer than cold. I'm unsure how heater systems work, but I'm assuming there was static water getting a good warm up until I flicked the fan on and moved it around? The heater has never really worked, maybe it's just not going to be particularly warm.

I only ask because I've got the battery, coil and all it's fixings off ( cleaning surface rust from the lower reaches of the engine bay) so have decent access to the 2 pipes going into the bulkhead if there's anything I can do there. I have heard about flushing the pipes out from under the passenger footwell, but t.b.h. I don't know if these carry the main engine coolant and I don't want to end up with a footwell of water/coolant. Basically which parts are being flushed out if I stick a hose pipe in the feed in the footwell?. I suppose I should've checked to see if the feed pipe was getting warm, I didn't, but I will tomorrow.


By the way does anyone know of a mains drill shaped like a Dremmel that will take a nylon abrasive brush, an angled drill is too big, need it small to get in tricky areas because my Dremmel takes forever.

Cheers

[rossocorsa]

many years ago i had a fulvia 3 in which the heater didn't work I had to remove the matrix in the end and swap it with one that wasn't blocked the design of the system seems to encourage silting up strangely if you put a garden hose on a blocked matrix water still appears to flow as it seems to have a sort of by pass in the matrix. it's a pain to do as you have to remove some of the centre console/dash and pull the heater unit out but if you plan ahead carefully it's not too bad a job. heater was like an oven once sorted

[alcooker]

Okay, so it's dashside not engine side, glad you replied, I was about to take the air inlet box and fan off from bulkhead. Dash will be taken off at some point, it has a split near the vent, so Ill look into the matrix then. Are there any new matrix that will fit, I think my spare car's one is knackered aswell.

Cheers
Al

[philm]

I have just rebuilt and refitted my heater completely. Removing the dash will only get you so far. All the padding and the fuse box will need to come out if you are planning on removing the heater entirely. There is no bypass in the matrix, what happens is the silt sits at the bottom blocking the bottom rows, flushing will often just pass over the silt so you clear the upper rows but not all of them. The fan does not move the water merely pass air over it to pickup the heat from the core. The valve may be blocked, if you disconnect the inlet & outlet pipes you can back flush the system to help clean it. I havr 3 or 4 heater assys if you need parts/pictues etc.

[alcooker]

Phil you're really enticing me to change the heater, I'll give the flushing a go, if it doesn't work I'll just suffer on the odd crisp winter's day. I was tracing the heater pipes today, just wanted to see where they went, ended up taking one very rusty cooling fan off, now rubbed down ready for painting, one job leads to another. Am I right in thinking the pipe coming from the top of the rad going past the carbs is the flow? if it is, the return pipe has a T halfway down it's length engine side, is this a non return valve?, I'd like to know what it's purpose is. I'm pretty sure my cooling system has rad weld in it, if I flush the heater system will i need to put more rad weld in?

Thanks for the offer of the heater parts, I'll give you a shout when I get round to the big job. Wouldn't mind seeing some pics though, be nice see what the heater looks like.

Thanks
Alex

[philm]

There is nothing in the T it is just blanked off, I cannot remember which is flow and return, I will take some pictures though for you. Taking the whole thing apart and rebuilding it is pretty straight forward. You get to marvel at the unexpected use of corduroy on the inside of the vent flaps...............

[alcooker]

Well I suppose Corduroy was pretty popular in the 70's, look forward to the photos.

[willn]

Hi, I just joined the forum. For this particular issue, I can possibly contribute something. Have you considered flushing the heater with bleach? - i,e domestos? This was a trick Harry showed me. It was a big success on that particular car and I have since tried it again once on a Fulvia Zagato with a blocked heater and it worked well.

Procedure is drain the coolant via drain plug bolted onto the subframe (obviously), then disconnect the small hose connected to the drain plug on the heater side of the plug. Put an empty bowl under the disconnected hose under the subframe and push hose down so it drains into the bowl away from the subframe, suspension etc.

Next open heater valve and disconnect the other heater hose from the engine and lift it up as high as possible so it is vertical,then put a largish funnel in the end of it. You then pour bleach into the funnel until it reaches the top of the hose. Important to lift the hose and funnel as high as possible to generate head pressure through the heater. On the occasions I have seen, the heater core was so blocked that the bleach stayed level with the top of the hose for up to an hour or more before eating away the blockage and slowly starting to flow through. Harry rigged up a piece of stiff wire wrapped around the hose to hold it and the funnel vertical and hooked it to the bonnet (top of the bonnet support prop i think) so he didnt have to keep holding it. Careful not to overflow bleach or get it on your hands. As the bleach level drops, keep topping up until it starts to flow freely into the bowl. After this point flush through with loads of cold water to get rid of any traces of bleach in the hoses and heater core - at least 3-4 bowls full. (Note you are pouring bleach through the small hoses connected to the heater and the heater core only, not through the radiator hoses or engine cooling system) Then reconnect heater hoses and refill system (with plenty of inhibitor/antifreeze obviously) and the heater should work.

Apologies for the long description, hope it's reasonably clear. I know it sounds bizarre, but it worked for me. Good luck if you decide to try it.

[davidb]

Bleach WOW! Never heard of that one. I used Prestone flush
in both of my Beta heater cores. Cores out of the car, flush-
ing in my laundry tub. Active ingredient in that stuff is
sodium citrate. Glad the bleach worked, that's something!

[alcooker]

Well I'd considered using central heating flush but thought that might do more harm than good. I also considered caustic soda for a few seconds, the manual suggests a mixture of some kind of soda, but I was just going to try Wynns coolant flush. I took the radiator fan off the other day to refurb it and now having seen Spyder's redurbed rad I'm taking mine off tomorrow to get recored and sprayed up, I can clean the front subfame up at the same time.
As Wynns pro stuff doesn't seem to be available in local motor factors I shall be clearing Sainsburys out of bleach tomorrow, got to be worth a go. If I get Domestos bleach which frangrance did you find worked best, lemon fresh or scents of summer?
thanks for the tip, I'll let you know how I get on. Oh and thanks Spyder for enticing me into spending another £120 on the HF!