Heater blows cold

[MACCA.GLM]

Hi All

On a recent drive out a problem occurred with no heat from the heater on my sprint, It just blew cold air wether the valve was open or closed I am thinking airlock.Any thoughts as to rectify the problem would be greatly appreciated.

Regards

G

[tonyabacus]

Hello G

Sounds like an airlock, so as a first thought, try closing the heater valve, disconnect the pipe going to the heater matrix and remove the rad cap. Next fill the disconnected pipe with water and see if you can blow down the pipe to see if the water level in the radiator rises, if so try filling the pipe some more and blow again. Hopefully if it is an airlock you may be able to blow it through. Use a G clamp or similar across the pipe so water does not escape when you reconnect the pipe to heater valve.

Let us know how you get on so others can chip in with suggestions if the above does not solve the problem.
Tony

[MACCA.GLM]

Ok Thanks Tony

I will have a go at it

Regards

G

[MACCA.GLM]

Had a look at the Elan today and did what was suggested although seems a bit more heat but its still not right

I have no radio fitted so I could get my hands inside to check the input pipe to the heater matrix very hot but on the output pipe only Luke warm , could the matrix be blocked plugged. Also the pressure coming out of the heater valve did not seem that strong when opened fully but I could not run the engine with the pipe of that for obvious reasons

The return pipe to the engine pump side is only Luke warm even after a run out so I'm thinking matrix has some kind of restriction.

I will try to blow pressure from the output side to see if anything has blocked the input side into the matrix

Any more suggestions please

Regards

G

[JonB]

Yes. Don’t overpressurise it with an airline. Easy to damage.

I’d flush with water via a garden hose. First in the direction of flow, then backwards flow if you get my drift. You might also try soaking it in a flushing solution to loosen any crud, or descaler.

[MACCA.GLM]

Good idea

JonB

I will have another go at the weekend

Cheers

G

[JonB]

Let us know how it goes. I think mine needs a flush too!

[tonyabacus]

G

If the blowing fails try using a radiator flush product keeping the heater valve wide open, however be a little careful if you try blowing with this liquid in the system as you don't want to be swallowing any of it.

Take the car for a run till its nice and hot, then leave overnight to try and break down any sludge that has accumulated, then run it again before finally draining and refilling the system. From memory you can leave the product in the car for a while but check on the product container to verify
Tony

[MACCA.GLM]

Ok Guys

Ive flushed the matrix both ways and I took the car for a drive.Initially the thing seemed to be ok and heat was coming through vents and the input output pipes were hot.Then after about 10 miles back to square one no heat again

So back home I flushed again with a bit of air pressure from the output side.i noticed a lot of brown dirty water emerged. seemed odd as I'm running bluecol.Anyway flushed again until clear water running both ways without any restriction.

Im hoping this has cured it.Out for another run on next decent day.I will update then

Regards

G

[alan.barker]

Does the Radiator get hot.
Have you checked the Thermostat
Alan

[MACCA.GLM]

Hi Alan

Yes the radiator is hot and the fan cuts in and out

It seems as though the water from the heater matrix is not being allowed back to Main flow
When I take rad cap off the water is returning via thermostat to top of rad so I know the thermostat is ok.I took that out and checked that it was ok

the only thing I can suggest is the capillary tubes in the matrix are blocking
Something in there is not rt as the out feed pipe is cool I feed pipe is hot

Was strange on the last run it seemed ok for a while then went cold again

[Andy8421]

The heater valves are not an example of precision manufacture. It may be that the innards have come adrift from the actuating lever.

If all else fails, have a good look the valve and check it is operating OK.

Good luck.

[alan.barker]

When you first start the engine the hose to the Rad should stay cold and only hose to Heater heat up.
As said the Heater Valves are not that good and the Diaphragm might be in bits blocking circulation.
Alan

[MACCA.GLM]

Thanks for the input guys.

I will check out the valve to make sure it's ok in fact I will take it off and run direct that will tell me if its a faulty valve or there is a restriction in the matrix.

I will keep you posted

Regards

G

[The Veg]

This heater-valve is far superiour to the ones in British cars of the 1960s/70s:



It's for American Motors & International Harvester vehicles of the mid-1960s and both spigots are exactly the right size to use in an Elan or Plus 2. 90-Degree valve operation, turns easily, been meaning to attach a cable to I can operate it from inside the car. Was under $30 but I forget where I bought it.