Morris Minor Owners Club

Does anyone get a good air flow air from the footwell heater vents (the ones that have a 1.5"" (approx) pipe from the heater through the parcel shelf)? Or are they generally accepted to provide minimal output?
There is a good and fairly hot flow from the main vent when on "car" and also a reasonable flow to the screen when on "screen", but little heat from these two down pipes at either setting (don't really expect it from "screen"!). This is with the fan on or even without, and using air from the intake from the radiator grille.
I have even blocked the passenger vent to improve the drivers side flow - no increase.
I ask as I don't fancy taking the heater etc apart to find that this is as good as it gets with the standard heater!
Thanks for any help/advice, Paul

Hi Paul
Your heater sounds like its output is similar to my own , and others I have had in the past have been worse if anyone has improved things without resorting to a mini heater matrix of one of the Birmingham centre improved heaters, I would also be interested to hear.
Coming to think of it does anyone have or tried one of the improved heaters and what do they think of it

Kevin,
thanks! I kind of suspected that it would be normal - but this forum is a great way of being reassured!
When I first had the car, the 4" pipe from the rad to the heater was crushed and holed, when I replaced it the difference was unbelievable. It literally blasted hot air into the cabin. I had a faint hope that might have had some simple remedy for this!
Thanks, Paul

My heater sound pretty similar. The pipe has a couple of small holes in, but nothing major. And it still gives quite a hot blast when going fast enough.

I reversed the car's polarity but never did the heater. It still works but I suspect that it is not really that efficient.

has anyone done this? and if so is there much of a difference - is it worth doing? (not that it's difficult, I just wondered).

If I remember correctly if you do not reverse the wiring (only 2 wires I think) it makes the fan suck rather than blow, although the ram effect from the speed yours goes at Cam I suspect it overcomes the shortcomings.
Although what Paul mentioned about the underbonnet pipe having holes in it is a good point, because how often do I look at it if it appears Ok

Actually Kevin, when I had the blowing exhaust manifold and carb overfuelling problems, you could really smell the fumes when driving along, so the holes in the pipe must be reasonably sized.

Yes, the ram effect does produce more air than the blower

But my heater does blow (not suck). Although the vanes are reversed, it still pushes air out the same way, just reversed it is not as efficient. (I am talking about the late heater with the up-and-down control and the barrel type fan). Not the recirculatory type with a conventional (propeller type) fan, which would suck if reversed.

I would suggest from past experience that it is worth checking
the flow through your heaters, of whatever year. I did this and
was surprised by the very small amount of erratic water drops which
came out!! A good flush and treatment with kettle descaler gave
a very great improvement in flow/heat output. All you have to do is
to remove the heater pipe which connects to the bottom radiator
hose and extend it with a bit of tubing or pipe so that it will reach
the radiator filler orifice. Block up the small bore pipe leading to
the bottom hose(from which you removed the heater hose) and
then run the engine with the heater 'on'. You should see a good
steady flow of water into the top of the radiator, I certainly didn't
so I treated the heater to a long soak in kettle descaler,and,most
importantly, vigorous flushing in BOTH directions. This removed
vast amounts of rusty water and lumps of clag together with a
pile of black rubber particles. Well worth doing if you have tried
everything else. I have never reversed the polarity on my
recirulatory heater and it does not suck instead of blow!

Thanks Willie that sounds an easy way to check the heater water flow, but I have had similar lack of water flow caused by an air lock, but of course this only occurs after a change of water and then not very often if care is taken.

I flushed mine in December: backwards then forwards and backwards again, using a hose pipe on the heater hose, and running it through until the water coming out of the other pipe eventually ran clean.

The heat output doubled but it is still next to nothing - I'm going to have to check the water flow (checking the flow can be done as detailed by Willie)
Alternatively, if you don't mind the mess, just take the hose off (the one that goes to the bottom rad Hose) and stick your finger over the engine side. Hold the hose at the level where it comes through the bulkhead. If the pump is good, water should shoot out at tickover, and loads of water at higher revs.
If the pump blades have rotted away it will struggle to push water up the pipe - And if the pump is good, you get very wet.