S3 Heater - Summer 22 project - Major Improvement

Having moaned each winter about the poor heater performance, I did invest time and resources this summer to the whole heater system. Permission to be SMUG! New heater matrix, acid dipped & painted heater box. Used woodburner sealent putting it back together. New heater control valve - blue packet. Refurbed heater box mounted to bulkhead with new foam 1cm thick gasket. Lower dash out, acid dipped, welded all holes, primed & painted, buzzweld wax internally, new lower dash top plate re-installed with a 1cm foam gasket, screwed down to an inch of its life. Lower dash control paddles applied with neoprene to help seal footwell vents - and/or windscreen vent. Home made fume curtain added. For the first time, in 17 years, I have been warm, cosy, smug. The system, when well-maintained and cared for is actually, very good. So, anyone suffering (I do night shift) this winter, I would highly recommend a comprehensive review and condition. The heater rad was choked, the matrix box letting in cold air, lower dash letting it out plus the heater control was not letting in its full aperature of hot water - next time, the only thing I would change is probably loosing teh control and just hard plumb with copper pipe. I'm actually looking forward to the run home at 6am!

Its nice to know the terrible heater can be improved. What about the fan though, mine has less power than a gnats fart.

Col

I took my heater box to bit years ago....found same as you.....so many gaps around the matrix.....a lot air thats suppose to go through the matrix to be warmed bypast it....I filled the gaps with foam or what ever it needed.

Getting the thermostat at its best is important.seen several over the years with the completely wrong stat....the flat plat type rather than the type with a skirt.....the flat plat type with not seal in the housing.....allowing cold water to get past it into the rad...that stat may as well not be there......it will then take forever to warm if at all.

There should be a seal in the stat housing for the correct stat to sit agaist.....to stop flow while closed.

Now the biggy.....I fitted a ducting pipe from the heater box cold air inlet....to down to the left side of the front rad.....so it would get RAM AIR when moving.....a blower is not necessary then.....that blower is half the prob....on a S3 anyway being on the side wing.....if going much above 15mpg....it has a big job sucking in air.

I made a Y section that sits on the from of the S3 heater box.....one inlet gets ram air....the other is from the blower.....still needed if parked up and req the heater.....saying that if stopped and facing into the wind....thats enough to make its way up the ducting into the cab.

My heater has been brill for many years like this.....even with my full soft top.....downside....cant turn off in summer.....need to block the ducting or pull it off at the heater end...no big deal.

After all that work you deserve to be well warm ORJIP. Second nicjaxe about the crap position of series 3 heater air inlet. My old 2a with the square type on the inside of the bulkhead did a better job.

tottot said:

After all that work you deserve to be well warm ORJIP. Second nicjaxe about the crap position of series 3 heater air inlet. My old 2a with the square type on the inside of the bulkhead did a better job.

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Yes indeed...what were Landrove thinking putting the inlet on the side....stick you arm out of the winder....hold it close to the door when driving.....no airflow.

When it came to the Defender they put the air intake there, a position where the air pressure doe's not vary much and when wading [ at the right speed ] a depression in the water wave develops.

tottot said:

When it came to the Defender they put the air intake there, a position where the air pressure doe's not vary much and when wading [ at the right speed ] a depression in the water wave develops.

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Dont seem to help the heater motor blow.

On the Defender they put the engine air intake in the side of the wing where the series 3 had the heater intake, quite a good place for that job for reasons in post above.
Only trouble then is they put the heater intake in the wing top where there is still no ram effect and if the drain in the duct blocks the heater unit fills with water.
You know this when you turn on the fan and every thing inside mists up and strange noises come from the passenger footwell. Aftermarket wing top covers available to improve airflow into heater

tottot said:

On the Defender they put the engine air intake in the side of the wing where the series 3 had the heater intake, quite a good place for that job for reasons in post above.
Only trouble then is they put the heater intake in the wing top where there is still no ram effect and if the drain in the duct blocks the heater unit fills with water.
You know this when you turn on the fan and every thing inside mists up and strange noises come from the passenger footwell. Aftermarket wing top covers available to improve airflow into heater

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If you feel the air output from the blower as the speed increases.....it starts to blow in puffs.....and is very inefficient.

nickjaxe said:

If you feel the air output from the blower as the speed increases.....it starts to blow in puffs.....and is very inefficient.

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Puffs came to my mind anorl.
As long as it’s warmer than a motorbike it’s a win.

I’ve actually been using my diesel heater this year. Just in short bursts as it melts the windows otherwise