25 replies to this topic

[dan1zo]

Hey people,

I've gone and removed my old heater and will be replacing with a nice tidy unit from T7 design to actually get some heat in the winters!

https://www.t7design...-vents-12v.html

 

When i took off the old unit the water that came out was really dark rusty, the pipes seem to be 'crispy' on the inside like they are lined with rust.

Whats the advice on flushing the system? I'm not really sure where to start.

 

Or is it better to just get a big load of pipes and just replace the lot?

 

I don't fancy having all that gunk going through my nice new unit as its probably why the old one is dead.

 

Cheers all

Dan

[riktanius]

I want to know about this too. I havent decided what I wanted to do about the heater unit, but I know I will be replacing it and might be doing the same thing you are. 

[dan1zo]

I'll post some updates as i fit it in. Its a really lightweight unit and blows hard too (i hooked it up to a battery i had lying around).

Will be useful to have a bit more leg room as its tiny compared to the standard one.

[roblightbody]

Fascinated to see how this goes!

[Steve220]

So that just circulates? Or do you intend to use a fresh air feed for it still?

[Tupers]

Before you go fitting that you might want to look at the heater matrix inside the standard unit.

The get clogged with rust and sludge just like any other radiator and loose efficiency over time.

[dan1zo]

So that just circulates? Or do you intend to use a fresh air feed for it still?

Its a circulating heater, but i may play with the possibility of running the fresh air feed to it too.

 

Before you go fitting that you might want to look at the heater matrix inside the standard unit.

The get clogged with rust and sludge just like any other radiator and loose efficiency over time.

Yeah i though of replacing the matrix and cleaning it out, but i saw that little unit and thought why not just get a more efficient, smaller modern unit. Less hassle and also nice to have the directional vents for my feet too.

It is also that the fan in the unit was blowing about as hard as a mouse with asthma. I'd had a leak where the panels around the window had rusted away and i suspect it got pretty water damaged since it was ages until i got it fixed.

The car had been sitting untouched for about 6 years before i got it driving again in October last year. So there is a lot still to do to get him back to my daily drive.

 

I think i will end up having to replace the hoses right up to the thermostat, having a feel around, they are a bit crusty too. Or do you think i can give them a good clean out to get rid of all the crud that has built up?

Edited by dan1zo, 16 April 2019 - 09:59 AM.

[dan1zo]

Been a little while since i posted but some progress made.  I ended up taking out all of the water pipes, giving them a good flush and will replace them in the car soon, they were still in good condition.

 

Fitting the new unit has been a bit of a struggle, mainly in where to attach it to, where to move other stuff to accommodate it and where to run the pipes.  The MPi has 5/8" water pipes and the unit is 1/2" so you'll need a length of that and a couple of reducing adapters.  To complicate the electrics i bought a fan control unit with a potentiometer so i can control the fan speed.

 

So my plan to just swap it out has become a bit more awkward. If you are planning on doing the same, cable ties are your friend. It means you can get the unit roughly where you want so you can see where the pipes will run and get them to length.  However, the mounting holes don't match up with any existing holes under the dash, so you either will have to find some brackets or drill some holes. not sure which i'll do yet. I'm still at the cable tie stage. 

[brivinci]

Any pix of it in situ? I’d love to see how it compares.

Not sure how cold it gets where you are but I’ve driven mini mini in some really cold weather and the stock heater was decent. I just have a single speed unit in my SPi and was thinking of adding a fan speed control as well.

One thing to consider is that without fresh air, you are going to have one steamy car! Why is your plan on the demister?

[dan1zo]

It gets a bit chilly here in Kent over the winters, but my old unit was hardly blowing any air so it basically did nothing anyway!  (i always had a sponge and a scraper handy to get rid of condensation AND ICE on the inside of the windscreen).

 

The unit will be running the demister and the footwell, i'll still have fresh air from the dash vents, just not currently to this heater but there may be scope for change depending on how it works over winter. If in doubt, i'll just crack the window open a little 

 

So this is a decent comparison of the size of the units. MUCH smaller.

 IMG_20190415_172914.jpg   100.49K   4 downloads 

 

Here is the front switch panel. Its easier to work with it out to give your hands a bit of room.  You can see that i've moved the temperature pull to the left where the choke would be on older cars and the actual unit it connects to is now behind the glove box. On the right is where the potentiometer sits (it has a separate control unit that i need to find a home for. As you can see, my wiring is a bit of a mess at the moment, i was working out where was best to run everything.

 IMG_20190430_103328.jpg   64.62K   6 downloads

 

Last one in situ (sort of).  Pipes are just loosely fitted with the 5/8" to 1/2" reducers, not fitted the pipes to the demisters yet as they were getting in the way, but you can see the holes where they attach.  I may keep the unit slightly angled like this (but not as much) as it gives a bit of extra clearance to the pipes at the back and still keeps it fairly hidden from view at the front

 IMG_20190430_103548.jpg   65.46K   5 downloads

 

Its a slow process for me between work and having a garage full of junk that i can't use at the moment. So its just when i can get time.

 

Certainly be worth it in the end!

[brivinci]

That is a massive size difference! I hope you can work it all out. Would be a great mod.

[MikeRotherham]

I think to get the best out of standard heater the matrix and piping needs to be clear.

 

I purchased new a 1978 mini 1000 and went through several winters with that without any problems. The heater kept the screen clear and me warm.

 

I now have a 1994 mini 1275 auto and the heater is also well up to the job. Similar to the MPI version but without the 2 speed fan.

 

I think it is just down to good maintenance and is well within the abilities of most mini owners.

[A-Cell]

I think you might be disappointed with the result. 3.5kw is less than half the output of the mini heater!
It would have been a whole lot easier to replace the matrix and flushed the hoses?

[brivinci]

Mine always seemed up to the job unless seriously below freezing...but I try not to drive my mini then. What I like about this is the super compact size. I would LOVE to have a dead pedal for my foot to rest on

[dan1zo]

Hey guys

 

Yeah i could have replaced the matrix, the hoses are actually alright too, but I believe the actual fan part of it was dead or dying.  It never pushed much air through since i got the car and as a result never cleared the windows.  Most winter or cold weather drives began with sitting for ages hoping the windows would clear and then deciding that a sponge or ice scraper was faster and driving with the windows open.

 

So rather than taking it all apart i thought, while i'm repairing the rest of the car, a nice new efficient unit was worth a shot.  And it really does push the air through pretty strongly, probably using less power too.

 

Adding the directional vents is a nice touch.  I think for me the 3.5kw will be sufficient, the car is small enough  , but i'll find out soon and the reduction in size and weight is nice too.

 

Hopefully i'll get it all hooked up properly this weekend before i tackle my next problem - the fuel pump.

 

Dan