Heater blowing cold!

[Mario]

This is puzzling me.... the Coupe's heater is blowing cold on all settings.

A week ago it was great, all functioning perfectly and blowing hot air no probs.
It started to go wrong when the hot air stopped coming out the footwell vents and only feebly out the windscreen vents. Tonight it failed to blow any out even the windscreen vents. 

The engine is warming up perfectly, every hose seems to get hot on a quick inspection.
When moving all three dash sliders it sounds like flaps and levers are quite clearly moving!

A bit baffled and not knowing where to start... don't really want to pointlessly rip stuff apart!
Any common faults here or anyone have any ideas?

[rossocorsa]

I'd check the heater valve first maybe it's even as simple as a loose connection, don't know about Betas but on flavias the heater valve is nearly always the culprit they sometimes fails blocking the water flow

[Mario]

I'd check the heater valve first maybe it's even as simple as a loose connection, don't know about Betas but on flavias the heater valve is nearly always the culprit they sometimes fails blocking the water flow

Not familiar with the setup..... where would I find the valve, and what faults would I be looking for?

Loose connection? All the electric aspects seem to be working (fan works) but the heat isn't being distributed. 

[Mario]

Just investigated this part further.... will check if their is a loose connection to the valve.

How does this setup work anyway? Never seen an electrically varied heat supply! 

[thecolonel]

I think it's a misread post : heater valve or loose connection.

from what I remember heater valve is attached to side of heater  (passenger footwell)
often a plastic/abs valve, the sealing ring can separate and block flow.
Also matric is quite fine and may require flushing.

Geoff
(of course I could be thinking Fulvia, I'm at a funny age)

[Thotos]

Later Betas (certainly by S3 e.g. my Trevi) have pneumatically actuated heater controls just like the Gamma and have the same heater valve as the Gamma mounted in-line with the heater hose in the engine compartment. I don't know if earlier Betas had mechanical controls with valves elsewhere... But if the vacuum pipe is disconnected then the heater valve defaults on the ON position.

[HFStuart]

My 1978 Spiders have cable operated controls for the heater valve.

One less thing to go wrong !

[Mario]

Ok.... found the valve, seems to have no electrical connections, just cable operated.
All looks like it's working ok visually so I'm guessing either the matrix is blocked or the valve is somehow stopping flow?

How can the valve stop flow, not really sure how it works (or even why it's there?!).

What's under the dash....

[Mario]

Found this valve for sale, but thinking it looks different now....
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270362046598&ssPageName=ADME:X:RTQ:MOTORS:1123

Anyone got a good one for sale?

[Thotos]

The valve you found (as in the photo below) is the pneumatically operated valve as fitted to the later Betas. But why change the valve? If it's not leaking and it opens and closes when the cable is operated then it should be OK. Might need cleaning but doesn't need changing.



I'd say take the cap off the expansion bottle (or radiator if that's where it is on earlier cars) and start the engine. Once is at temperature, squeeze the hoses going to and from the heater matrix to get out any trapped air. You might just find that's good enough to get the heater going again.

[thecolonel]

The valve on the side of the heater box, as previously mentioned, has a sealing "o" ring these can
be dislodged and reduce flow. Most likely the matric is full of sediment and needs a flush.

Geoff

[rossocorsa]

Ok.... found the valve, seems to have no electrical connections

sorry about confusion i'd meant that the operating cable might be loose or broken not an electrical connection!! it might be worth trying manipulating the valve to fully open by hand sometimes they don't open up enough just by cable operation

as regards the valve itself they do sometimes fail it might be worth taking it off to check it but firstly I'd look to be 100% sure there isn't an airlock somewhere. On some earlier lancias (again not sure on Betas) the rubber seals inside the valve swell up with age and when they get hot they swell up so much they stop the coolant flow. I can't remember how the heater air flaps work on a beta, certainly on fulvias there is one that blocks airflow through the heater when set on cold if that sticks you don't get warm!

[Mario]

Not had a chance to work on it again, but have noticed that warm air (not really that hot) is now able to come out the top vent but nowhere else!

Very confusing! 

[hutch6610]

Now if i remember the two Trevi's i owned in the past, the heater valve (shown in the picture) only utilized the "pneumatic" part to turn the water supply off.... incidentaly its the same valve that the Volumex uses to maintain manifold temperature for the carburetor.


You had to rotate the temperature control to red to open the valve .... sure its got a cable to open it.
Press a button on the heater and it would rotate the the control to cold - up or down was also pneumatic if i remember.

Mario, if both the feed and return pipes are hot it could be the flap inside the heater needs to be adjusted due to wear and tear ... that's if you have checked that water if flowing through it correctly.

This is precisely the problem i had with one of my Trevi's.

The photo of the valve - under the dashboard - shows the cable connecting to a crank mechanism ..... see the shaft its connected to first (with the two Allen key locking bolts?)

Well that shaft connects to a flap inside that diverts the air over or away from the matrix depending on which way the lever is set hot or cold, the idea is to blend the air to get a perfect mix or shut it off completely ....... but i think you all know its all or nothing with a Beta!

Put a tippex mark across it for reference - along the end over the plastic and the center shaft.
Set the heater to Hot (full red) to the right and the the cold air flap lever (second one down ) full to the right as well.
It looks in the closed position in your photo ... don't quote me on that, driving the bloody things for twenty odd years and i can't remember which way it is now!
Watch which way the lever goes and undo the two lock bolts, you then rotate the flap with a pair of grips or similar full in the direction the cable is trying to push it in - should be clock wise from your photo i think.

See what happens, if you get hot air then you just lock the two bolts back up in that position.

If no luck i am afraid the matrix is probably blocked - if an o ring has dislodged it would leak plain and simple - you would have antifreeze coming down your heater from around the valve where it bolts to the matrix and you don't.

Ask a stupid question now .... but does your car warm up correctly - that's a third to a half on the gauge?
 

[Thotos]

Has there been a resolution to this problem?

My Trevi started doing it now.    I get warm air at normal driving speeds but while the car is idling in traffic or at high speed on the motorway, the heater goes cold. 

[Thotos]

Well it seems it was restricted flow through the heater matrix that was causing my problem. On the way home this evening I froze as no heat was coming out of the heater at all. So I drained the system and disconnected the pipe into the heater matrix by the heater valve in the engine compartment. I tried blowing through it and nothing! My lungs should be fairly strong having given up smoking 21 year ago  but I couldn't blow through it. So I used the hose pipe with full mains water pressure and lots of yucky brown water came out the other end. Then I back-flashed it by disconnecting the pipe at the bottom of the expansion tank and fitting the hose pipe there and lots more brown yucky water came out the heater hose. I kept flushing and alternating on the pipes so water was forced both ways through the heater matrix until I only had clear clean water coming out. Seems to be working well now with plenty of heat coming out of the heater but the real test will be the drive to the office tomorrow in North London traffic. 

[Thotos]

It was like a sauna in the car during my drive to work this morning    It took a while to start heating though which makes me think there's still a blockage somewhere. In the end I had to open the windows and the sunroof as I didn't want to turn the heater off in case it wouldn't come on again.   

[Mario]

Still not sorted our heater!
Really have to now though as it's unbearable in sub zero temps!

The engine's heating up fine so I'm going to try hutch's very informative advice tomorrow!

[Mario]

Just tried adjusting the levers.... engine hot but still no heat regardless of which way it is!

Would I be right in thinking that the outer lever that goes to the valve blocks/unblocks the water flow to the matrix?

Also noticed a slight leak from the valve's flange to the matrix.... think there may be a blockage.

Anyone got a spare valve or matrix?

[Thotos]

It was a blockage with my Trevi but I didn't need to change anything. Just used a garden water hose and forced lots of water either way of the matrix by disconnecting the hoses inside the engine compartment.