Heater

[dogoncrazy]

I,m somewhat disapointed by the output from my heater which can only be described as lukewarm at best.I've tried the usual bleeding the system etc but with no noticeable difference so am thinking the matrix may require replacement.I really don't like the idea of dash removal and heater unit and as the matrix comes out into the drivers footwell would removing the steering column out of the way be a simpler solution.Has anyone else done this or can offer a quicker solution to the dash/heaterbox idea.
The engine holds an almost constant 80 degrees and the pipework in /out is too hot for holding long period of time. engine is BMW M20 not that it should make a difference just that it is not easy to bleed in my opinion.

[greyV8pete]

Re: Heater

Hi Alan. Worth a quick check first that the inlet and outlet hoses at the heater matrix are the correct way around? In at bottom, out at top to let the direction of flow purge any air. If they are wrong maybe cut and swap in the engine compartment for a quick fix. Saves standing on your head under the dash! Peter.

[Mike]

Re: Heater

Hi Alan
Hope you are enjoying BMW power.
Have you tried flushing the matrix, using mains water hosepipe pressure. Sierra matrix often silted up, so this may help? Much easier than taking it out.
It might be worth adding a bleed screw via a T union in the outflow side of the matrix/engine bay to ensure you can bleed air out?
Regards
Mike

[djj_engineer]

Re: Heater

Hi Alan
I'm afraid the first thing that was fotted to FMB was the heater. Everything else seems to go in afterwards. Although I think it will come out without the dashboard being moved I don't know that you will be able to see what you are doing even if you can reach the pipes and fittings to remove them. I changes the outlet vents to push more air to the passengers feet, but then Jenny didn't like it!!

[pdm_engineer]

Re: Heater

Hi Alan
There should be enough heat from a sierra heater to almost burn your feet! Is your heater actually from a sierra or is it one of those after market things?
Peter L may be right in that the connections are wrong.
Check that your cylinder head rear connection is connected to the heater matrix top connection.
The other thing that happens is the internal foam seals around the matrix turn to dust. So unless this was attended to when the car was built this may also be the cause of your problem. I made new seals from thin foam sheet used to support model train rails. (local toy shop sourced)
Derek is right, it will be a major strip down to gain access to the heater.

[keith_h]

Re: Heater

Hello Alan, I made my own heater box using the Sierra blower, 3 speed switch and matrix. As Peter says, you can burn your feet if you want to. The drawings are on this forum somewhere. I you can't find them get in touch and I will email them

[greyV8pete]

Re: Heater

Alan. The heater on my Hunter will fry your leg if on full heat position. I still suspect you have an an air lock. Mine has a bleed screw in the highest point of the delivery hose in the engine bay. Simple design using a 5mm nut brazed onto a length of brass pipe with a small hole drilled thro the side. Screw with grooves filed along the lenght of the threads (like a lemonade bottle) and a fibre washer does the venting / sealing. Seemples!
P.S. I had to replace the metal connector in the return heater hose as it had corroded enough to nearly block the pipe. Worth checking if yours has the same set up / problem?
PPS. Be careful if using cold water mains to flush out as the pressure will way exceed the 8 or 10 psi that the system is designed for and may burst the matrix or end seals. PL.

[dogoncrazy]

Re: Heater

Thanks for the input guys. Remove the hoses and backflushed the matrix yesterday and got a 'dirty discharge' .Flow through appears to be good and as yet have not tried the car out to test if any difference. Peter - will check out hose position as I have the feeling its the other way round. Standard Sierra system fitted as opposed to aftermarket.