Heater controls - how are they meant to work, mine = poo!
Discussion
Hey chaps!
Started some more work on the wedge today (85 350i), had all the centre console out.
Whilst I was there, decided to free off the seized heater controls, and see what's what.
With the engine up to temperature, I couldn't actually notice much difference, regardless of how the controls were set.
I assume that the left hand control is meant to be temperature control, with the left directing air.
Are there any footwell vents? Or is the air dovert purely for sending air to the demisters?
Just trying to get a feel for how the system is meant to be in tip-top order before I over-analyse things!
Bob
Started some more work on the wedge today (85 350i), had all the centre console out.
Whilst I was there, decided to free off the seized heater controls, and see what's what.
With the engine up to temperature, I couldn't actually notice much difference, regardless of how the controls were set.
I assume that the left hand control is meant to be temperature control, with the left directing air.
Are there any footwell vents? Or is the air dovert purely for sending air to the demisters?
Just trying to get a feel for how the system is meant to be in tip-top order before I over-analyse things!
Bob
The heater is pretty much a recirculating design on most Wedges, even those that have a fresh air intake tend to have only the one setting - sweaty
The footwell heat isn't actually directed much into the footwells, it's sort of tipped out the side of the heater box via two short flexi hoses and tends to fry the passenger's knee (well in my car anyway).
In essence you have a valve in the hot water inlet to the heater matrix and a hinged flap inside the box. The valve may stop the water circulating per se but the trapped water still seems to maintain a thermosyphon effect and you never really seem to get cold air through.
The flap relies on various foam seals to stop the air blowing the wrong way around the box but after so many years most of the seals have dropped to bits.
The demist vents seem to have been reconfigured several times over the years in an effort to improve screen clearing, maybe the very late cars were OK in that respect but my '87 car is as dire as most of the precedents.
Finally, the convolutions of the box means that the fan wastes most of its energy wafting the air around inside the box rather than propelling it meaningfully in any given direction.
Someone on here a year or two back did a redesign of his wedge heater and reported significant improvements as I recall... someone will put their hand up, I'm sure
The footwell heat isn't actually directed much into the footwells, it's sort of tipped out the side of the heater box via two short flexi hoses and tends to fry the passenger's knee (well in my car anyway).
In essence you have a valve in the hot water inlet to the heater matrix and a hinged flap inside the box. The valve may stop the water circulating per se but the trapped water still seems to maintain a thermosyphon effect and you never really seem to get cold air through.
The flap relies on various foam seals to stop the air blowing the wrong way around the box but after so many years most of the seals have dropped to bits.
The demist vents seem to have been reconfigured several times over the years in an effort to improve screen clearing, maybe the very late cars were OK in that respect but my '87 car is as dire as most of the precedents.
Finally, the convolutions of the box means that the fan wastes most of its energy wafting the air around inside the box rather than propelling it meaningfully in any given direction.
Someone on here a year or two back did a redesign of his wedge heater and reported significant improvements as I recall... someone will put their hand up, I'm sure
Heater controls.
Roof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a f
king thing.
Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
Roof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a f
king thing.Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
carob said:
Heater controls.
Roof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a fking thing.
Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
Roof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a f
king thing.Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
like it....Superb chaps, thankyou!
Looks like I probably ought to go the whole hog then and strip the heater box out and rebuild it.
I want to change all the engine hoses anyway, and sods law says that if I don't change those running to the heater, they'll be the ones to fail.
Making Chatsworth, by now, is appearing to be an increasing work of fiction!
Looks like I probably ought to go the whole hog then and strip the heater box out and rebuild it.
I want to change all the engine hoses anyway, and sods law says that if I don't change those running to the heater, they'll be the ones to fail.
Making Chatsworth, by now, is appearing to be an increasing work of fiction!
Rainx antimist is very good, not to be confused with the outside application which is also very good. The only draw back is it needs cleaning off as it tends to gather dust.
Of course, being a roof off person (before the roof stasi nab me....) I read about this on the back of a rice crispy packet or something....
I did my heater hose from the engine last year. They were twisting on the tube no matter how tight I got the clip..... the pipes had gone a tad soft.
Of course, being a roof off person (before the roof stasi nab me....) I read about this on the back of a rice crispy packet or something....
I did my heater hose from the engine last year. They were twisting on the tube no matter how tight I got the clip..... the pipes had gone a tad soft.
Edited by jmorgan on Wednesday 28th March 10:07
jmorgan said:
Rainx antimist is very good, not to be confused with the outside application which is also very good. The only draw back is it needs cleaning off as it tends to gather dust.
Of course, being a roof off person (before the roof stasi nab me....) I read about this on the back of a rice crispy packet or something....
I did my heater hose from the engine last year. They were twisting on the tube no matter how tight I got the clip..... the pipes had gone a tad soft.
Is that one of ACT's silicone hoses? I'm looking at getting their whole engine bay kit.Of course, being a roof off person (before the roof stasi nab me....) I read about this on the back of a rice crispy packet or something....
I did my heater hose from the engine last year. They were twisting on the tube no matter how tight I got the clip..... the pipes had gone a tad soft.
Edited by jmorgan on Wednesday 28th March 10:07
carob said:
Heater controls.
Roof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a fking thing.
Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
That is just too goodRoof up = warm, but dont get caught.
Roof down = cooler, chim owners may need this explaining.
If you happen to be a roof up person!!!!
Window up = steamy windows cant see a f
king thing.Window down = colder, but able to see chim owners teeing off from from a distance.
Rob
I think the design brief was heater must be poo so wedge drivers WILL always drive roof down!
My early 280 worked a lot better after I realised that those two vents in the middle of the dash were flapping about in big holes in the heater box with no foam sealer left. I blocked off the box holes entirely, and the screen demist now *almost* works !!
(I don't think those vents are there on the later wedges?)
(I don't think those vents are there on the later wedges?)
The heater matrix is likely to be full of gunge which has to be cleaned out or have a new core installed £60-70 at a guess. When you take your heater apart you will find gaps everywhere for air to wander about wherever it likes. My ex FHC had two fans which were fighting each other and managed at the same time to provide hot air through one fresh air vent and cold through the other.
I binned one fan, one fresh air vent, recored the matrix and made a seal for the remaining fresh air vent where it went into the heater. Replaced the strange looking water valve with a new one that worked.
Tried to put a seal round the big flap which appeared to be made out of boilerplate which was handy as it was very rusty. On reflection I would have binned the flap and bought some vent valves to go onto the end of the hoses to control the flow of heat into the cabin. This would mean having the demist always working but if you need cabin heat you need demist. I also changed the flexible cabin pipe for some drain pipe and a 135 degree bend.
When you put it all back together mastic every gap even the ones on the fan. Mine could demist provided I didn’t breathe too hard. This is my magnificent sealing of the fresh air vent from the heater. Admire the craftwork. The box was made of wood which I sprayed black to disguise how awful it looked. I lined the inside of the box with foam and jammed the vent in.
The flat black plastic is yellow on the other side and says No Horses Allowed By Order something-something Council. Well we are supposed to recycle things.
I enlarged the dash hole for the missing vent and put a radio there. I also put thick foam on top of the under bonnet intake to ensure it was fresh air coming in until I changed that as well.
I binned one fan, one fresh air vent, recored the matrix and made a seal for the remaining fresh air vent where it went into the heater. Replaced the strange looking water valve with a new one that worked.
Tried to put a seal round the big flap which appeared to be made out of boilerplate which was handy as it was very rusty. On reflection I would have binned the flap and bought some vent valves to go onto the end of the hoses to control the flow of heat into the cabin. This would mean having the demist always working but if you need cabin heat you need demist. I also changed the flexible cabin pipe for some drain pipe and a 135 degree bend.
When you put it all back together mastic every gap even the ones on the fan. Mine could demist provided I didn’t breathe too hard. This is my magnificent sealing of the fresh air vent from the heater. Admire the craftwork. The box was made of wood which I sprayed black to disguise how awful it looked. I lined the inside of the box with foam and jammed the vent in.
The flat black plastic is yellow on the other side and says No Horses Allowed By Order something-something Council. Well we are supposed to recycle things.
I enlarged the dash hole for the missing vent and put a radio there. I also put thick foam on top of the under bonnet intake to ensure it was fresh air coming in until I changed that as well.
Edited by MJG280 on Wednesday 28th March 20:39
Dashboard came right out for more months than on a calender,then inspected heater box once is managed to pull it out then destroyed it,but it was such a mank of an old slapper I had no choice. I then went about making a new box using some 6mm polycarbonate I had lurking around and adapted the fan to for it,I did have to resolder the matrix on inlet spigot also then tested it under hot pressure,twas fine. Once box was made with added plumbing bends inside to improve airflow every joint needed adhesive to seal it,should hold water even when matrix leaks. It took some farting about to make the shutters for diverting the air and hot to cold plus getting them to marry up again with the two control dials but I've got there. Must add that I made the very front cover of box removable once switch console is 'lear so that the matrix will extract frontways without removing rest of dash,apart from all that twas a piece of proverbial urine!!
The other thing is triple check ya measurements like what I didn't,that's why I made it put it in then took it out again,twice,kept me off the streets though.
The other thing is triple check ya measurements like what I didn't,that's why I made it put it in then took it out again,twice,kept me off the streets though.
Hey chaps, thanks for all the info!
A quick update really. Have got the car in bits now as have really got stuck into its restoration.
Before I removed all the coolant hoses, Dad and I ran some tests to see if the cooling system was beahving itself.
Bizarrely, at an indicated 95degrees and with the radiator fan running, it wasn't drawing hot air at idle.
It took the engine being revved for hot air to be drawn through the rad, which made us suspect there was a terrible air lock in the system (or the water pump is knackered).
I therefore suspect that when the cooling system is re-installed and properly bled, the heater should actually work*
A quick update really. Have got the car in bits now as have really got stuck into its restoration.
Before I removed all the coolant hoses, Dad and I ran some tests to see if the cooling system was beahving itself.
Bizarrely, at an indicated 95degrees and with the radiator fan running, it wasn't drawing hot air at idle.
It took the engine being revved for hot air to be drawn through the rad, which made us suspect there was a terrible air lock in the system (or the water pump is knackered).
I therefore suspect that when the cooling system is re-installed and properly bled, the heater should actually work*
- as well as TVR heaters ever do!
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