Heater system

[Farmer42]

Hi

I have a heater that is blowing out cold air on my S30 even though the lever points to hot and the engine is hot. To be honest, it has never worked since I bought the car last May but I never really worried about it in the summer.

I have tried flushing the heater matrix but disconnecting the 2 pipes leading to it that pass through the bulkhead and water passes through both ways. the hoses get hot under the dashboard and there seems to be heat both sides of the hot water valve so I don't think that is blocked but I cant get any hot water to run through the matrix with the engine running and no hot air. The thermostat is fine (just replaced it).

Am I missing something? Could it be a dodgy water pump and is there any way I can test it without removing it first? Any suggestions would be greatly appreciated.

Thanks

Paul

 

[Rob Gaskin]

First of all do you understand the action of each lever - they are not intuitive in my opinion?

Are all levers operating the valve and flaps ok? Get under the dash and check. I've had issues with cable ends wrongly connected.

Fan working ok?

I know this is basic stuff but let's get it out of the way first.

 

[Farmer42]

Thanks Rob

I think I do!

The lever that points to hot & cold moves the cable that is attached to the water valve and that seems ok unless it is not travelling far enough to open it fully. But it had water flow both ways when I flushed it which I thought would indicate that it is working ok.

The other lever works the air direct and A/C and that seems ok as the air moves between screen and footwell. The final one is the fan and that works fine.

Still at a loss for a solution really!

 

[Rob Gaskin]

....... The other lever works the air direct and A/C and that seems ok as the air moves between screen and footwell. The final one is the fan and that works fine......

A/C

I don't know how this is configured into the system - I wonder if that is the issue?

So even though you have hot water in the matrix and the fan blowing, it's cold air coming into the footwell or screen?

 

[Farmer42]

Not sure that I even have hot water in the matrix but yes I have cold air coming out of all vents.

Not sure how the A/C works either but the switch is on the lever slide for the air direction and it switches on the pump when the lever points to it. I don't think it would stop the heater getting hot though unless I move the temp lever to cold which would close the water valve.

The more I think about it the more it seems to point to a dodgy heater matrix or a lack of water pressure driving the hot water through it. Don't really want to be taking a heater matrix out - looks a real 'mare of a job! Is there anything I can use that will clear all the channels? Tried the normal flushing fluids from car stores and there is a water flow through it but the question is whether it is through the whole matrix.

 

[Huw]

Hi Paul

If the matrix is blocked with silt, it would be best to get it reconditioned or replaced. The waterways in the heater are very small. The unblocking potions available may dislodge some but unlikely to get it working 100%. Have u tried flushing the whole system to ensure there isn't an airlock? Just a thought.

Huw

 

[moor634]

Hi Paul,

Take the pipe off from the bulkhead that goes to the 90deg bend on the block, remove the 90 deg bend you will find this may be blocked with crud, clean it out refit job done HOPEFULLY...

Trev.

 

[datty240Z]

The heater in my 80 Sunny is the same. I've had the heater core out a couple of times. The water runs through both ways but its too silted up in the fine capilaries to get any significant amount of heat up. I keep thinking there must be some chemical, acid or something that can dissolve the silt.

 

[Farmer42]

Thanks Guys

I have come to the conclusion that the heater core needs a whole lot more flushing out. Don't really want to go down the route of removing or replacing the matrix - too much hassle especially as I probably won't be driving the car much in Winter anyway.

Gonna try flushing again using a more powerful radiator cleaner, pour it in neat through the hose using a funnel and leave it for 1/2 hour then flush it through both ways several times with hot water. Hopefully it will dissolve any remaining crusty silt in the core.

Anyway, that's for another day - had enough for today!

Cheers

 

[Farmer42]

Decided to tackle this problem again a couple of weeks ago.

First of all, I decided to by-pass the water control valve in case that was stuck by using a long piece of heater hose. Still no joy. The hose was getting warm but not hot but it was hotter towards the engine end of it where it comes out of the block.

Decided to remove the control valve & check it then removed the whole heater core which was a really awkward job. I flushed it through a few times and filled it with boiling water from the kettle whilst it was stood in the kitchen sink. The whole matrix core was hot so in my opinion it was not blocked. Did find that the inlet tube had broken & was leaking so I found a local radiator place that refurbished and tested it for £20.

Put the core back in & connected everything up but still no heat although it was hot on the core side of the control valve so that wasnt faulty. The next stage was to test the water pressure so I disconnected the outlet pipe on the engine side of the bulkhead and ran the engine expecting a torrent of water to shoot out - no water apart from a few dribbles.

Took the outlet hose off the end of the heater core under the dashboard and whoosh - instant flood!! Turns out that all along, the outlet hose that attaches to the heater core had kinked and collapsed so it was like when you fold your hosepipe back on itself - it stops the water. It was just a normal piece of heater hose not the proper job with the bends in the right places. Problem is trying to get a new one plus I have now split the inlet hose which also has tight bends in it.

Will try to fabricate something this weekend out of a couple of domestic flexible tap connector hoses and some copper piping until I can get hold of the proper heater hoses. Hopefully that will be enough to let heat flow at last. I will post up how I get on with pics.

 

[spitdigger]

I've just had my heater box apart to fit new foam seals and clean out the matrix etc. The dual hard pipe section that goes through the bulkhead was on close inspection pin holed in more than one place and the hoses to the valve and matrix were hard.
To save time in sourcing another I made the hard section in 15mm copper and used a couple of off the shelf 5/8" hose bends. Olives soldered on the ends to give the hose clip something to grip to and an extra bend to get over the S bend hose.

 

[Farmer42]

Crikey Didn't quite go as far as you have and take all the heater box out. Probably easier to work on it that way as I had to become a contortionist under the dashboard to get to all the fittings.

Didn't realise that you could get "hose bends" off the shelf. Havn't seen them in any of the auto parts places I have been into so would be interested in where you got them from.

All in all it looks as though you have done a good job with that. Mine is a slightly different configuration as I have aircon so the heater hose runs through a vacuum control actuator which replaces the 2 pipes that go through the bulkhead. Just makes it a bit more awkward with more bends in the hose.

 

[spitdigger]

Hoses came from here http://www.carbuildersolutions.com/uk/ - lots of useful things in their catalogue.

 

[Farmer42]

Hallelujah!!!

Finally have a heater. Had to do some jiggery-pokery with some copper pipe and flexible pipe connectors from domestic heating plumbing bits but I have hot water flowing round the complete system - and no leaks to boot. Here are some pics of what I have had to do. A bodge i know, but it does the job!



Got some proper hoses on order but this has been such a pig of a job I will be a bit reluctant to mess about with it again. At least I will be ready for Jap Day at Castle Combe in May.

Wish I had known about Car Builder Solutions a couple of weeks back but it does look as though they have some really useful stuff. Just ordered a couple of chrome door mirrors from them.

 

[toopy]

A bodge i know, but it does the job!

As bodgies go, that looks pretty good as a temporary measure to me

I understand your reluctance to faff around with it all again when you have proper hoses etc, not only is access difficult, but you have to be a contortionist as well, and the constant threat of a wet interior!

 

[Farmer42]

Aaargh, spoke too soon!!!

Went to retrieve something out of the car yesterday and found bright pink water in the drivers side footwell. On closer inspection, it was leaking from a compression joint right at the back - the most awkward bit to get to. It seems as though it was ok when it was hot and expanded but when it cooled, it sprung a leak with a constant drip. I suppose that's what I get for trying something different.

Started taking it apart this morning on my driveway and just my luck, it started to rain. Wish I had a workshop!! Hoping it will stop later so that I can get everything back together otherwise I cant move it under cover tonight.