Heated windscreen washer jet

Can anyone help? I have been looking for a while for heated jets, even with strong washer fluid the jets still freeze up while the fluid is liquid. Problem is the cooling effect of the air stream over the windscreen and bonnet.

It seems a number of cars have them as standard now, including later discos and range rovers? Does anyone know of any suitable parts?

Many thanks for any help.

I bought a kit from BMW for my Mini Cooper to replace the washer jets with heated ones. Took ages to fit and was a complete waste of time! The jets heated up nicely, there was a little circle of melted frost around them, but the water was still frozen in the pipe where it connected to the jets.

Put some antifreeze in the washer bottle That'll cure it

redhand said:

Put some antifreeze in the washer bottle That'll cure it

Click to expand...

There is, and it remains liquid in the bottle and up through the pipes. The problem is that the jets are in the airflow, and the cooling effect and evaporation (which is how fridges work) freezes the jet. I have been thinking about this for a while and have noticed that many manufacturers including LR (but not on Defender) now install these.

Lateral thinking though is useful, thanks for helping.

nscnick said:

while the fluid is liquid.

Click to expand...

I like that one uber scientific

nscnick said:

and the cooling effect and evaporation (which is how fridges work)

Click to expand...

No it isn't. They rely on a sudden drop in pressure in the refrigerant which lowers the temperature.

The refrigerant is then repressurised again by the pump, which raises the temperature, hence why the back bit gets warm.

Just like in an air con system. Only they have a condenser in the airflow to remove water in the air too.

we have them in our bmw z3 and thay are ****e, i wouldnt bother fitting them, like someone said they defrost the washers but the water in the bottle then freezes!!

and if yer screens cold enough it just freezes on there or ya wipers!

biggest waste of effort and time..im sure you could spend your time better on summit else...an ashtray mounted on the drivers mirror perhaps

wiltshire landyman said:

...an ashtray mounted on the drivers mirror perhaps

Click to expand...

You could mount a sieve on the mirror instead. You could get an early start on your cake making this way.

big ad said:

we have them in our bmw z3 and thay are ****e, i wouldnt bother fitting them, like someone said they defrost the washers but the water in the bottle then freezes!!

Click to expand...

All part of the discussion about the concept. Though the washer bottle contents and pipes aren't frozen as I use a high concentration of washer fluid. I know it is the jets as I can pour cool or warmer water over them and they are fine. Once the antifreeze gets to the outside they are also usually fine, being an alcohol it tends to evaporate though so doesn't work for long. My screen is heated and that clears very effectively. The shape of the defender ones is a bit unusual so bodging something up from another manufacturer would be difficult.

Thanks for the experience, which seems to be a consensus that the idea is a waste of time.

boydy1989 said:

No it isn't. They rely on a sudden drop in pressure in the refrigerant which lowers the temperature.

The refrigerant is then repressurised again by the pump, which raises the temperature, hence why the back bit gets warm.

Just like in an air con system. Only they have a condenser in the airflow to remove water in the air too.

Click to expand...

While a fridge does use a pump and a pressurisation system it only makes it more efficient. It is the evaporation of a liquid through the air blowing over it that causes the lower temperature compared to the still air. Early fridges worked like that! Ultimately that is what wind chill is! The cooling effect through evaporation. How do hot drinks get colder by blowing over them? Also the air will tend to evaporate the alcohol in the mixture so reducing the concentration which won't help.

Difficult problem to solve.

How about using a pair of heated over grips from a motorbike?
They velcro over the bike handgrips and pump out a toasty 40+C.
I use them wrapped around the fuel filter to help heat up the waste veg oil/diesel mix, but I don't see why 1 of them under the windscreen washer bottle and the other wrapped around the pipes might not work.
Obviously it will take a while for the water to get hot by conduction, and the tip of the jet might remain frozen in the air flow (carburettor icing is the same effect and happens on my Bandit 1200 in very cold and wet conditions like now) but it's a cheap test.

Patman1200 said:

Obviously it will take a while for the water to get hot by conduction

Click to expand...

It's been a while since I thought about such things but I'd have thought that once the heat has conducted through the casing of the water reservoir the heat will mainly be transfered throughout the "water" by convection rather than conduction (which probably doesn't work so well down the hoses); and that it may take some time for heat applied at that end to melt the hoses. Worth a try perhaps.

I like the idea of using it to heat the fuel filter though. Where did you wire them into?

Convection, conduction, can't be arsed to remember my physics, but either way the pipes will get a little warm and the water will warm up eventually.

I wired them into my stereo 12v supply so they are only on when the ignition is on.

They are Oxford Hot Hands. I also use them on my dirt bike.

nscnick said:

There is, and it remains liquid in the bottle and up through the pipes. The problem is that the jets are in the airflow, and the cooling effect and evaporation (which is how fridges work) freezes the jet. I have been thinking about this for a while and have noticed that many manufacturers including LR (but not on Defender) now install these.

Lateral thinking though is useful, thanks for helping.

Click to expand...

I meant as well as the heated jets.

That's a damn good idea, I always thought of them as a bit namby-pamby on a bike and haven't given them a thought. If they work I might put them on the bike as well!

Many thanks.

Namby-pamby?? Namby-pamby is not riding your bike in winter 'cos it's cold. Heated waistcoat and heated grips I get to work in 30 minutes instead of 90 and warm and dry

I'm an old school masochist obviously! But then I run a Land Rover as well!