4 replies to this topic

[Jfcrouch72]

Everyone,

Having a nightmare with my mk1 heater...always blowing cold air.
Have checked matrix...clear.
Have checked heater valve....water flowing through when open, not when closed (as it should).
Hose from valve to matrix is hot...hose from matrix out to bottom hose cold.
Matrix cold.
I've blown through the matrix to see if it was blocked..it was fine.

Not sure what's causing thr problem....
Also..is the hose from valve to matrix supposed to be going into bottom of matrix and hose from matrix to radiator bottom hose supposed to be coming from top? Just want to ensure I've got the hose the right way round.

Thnx

[nicklouse]

Feed hose. From head should really go in the bottom of the Hester matrix. Top matrix hose to rad bottom hose.

What you need to do is open tap run engine with outlet hose disconnected from rad hose and check water is pumped out.

If not then do you have a stat. Fitted? Is water pump working.

[Jfcrouch72]

Thanks Nicklouse,
Glad to hear I haven't plumbed it together incorrectly. I will do the test that you suggested as well.

I have a nagging feeling that the pump might have gone...however, was not sure on best way to test this. Unless of course...this is the test!

I have seen water flying out of the valve when open (after taking the hose off it) and thought that might prove it's or king. ..but wasnt sure.

Any suggestions on testing for a faulty water pump?

Thnx

[nicklouse]

Water flying out is not the same as being pumped out. HOT water will fly out as it is under pressure.

From cold it will not. Oh stick something opinion the opening of the bottom hose or you won't have any water to pump round.

You want to start with a full rad and just the hose from the heater open. As soon as you start the engine you should get water pumping out. If you don't time to look st the pump.

Another pump test is take the rad cap off and rev the engine you should see the water level drop as it is sucked by the pump. Not much but you should see movement.

[Jfcrouch72]

Update.......fixed.

So, as per nicklaus suggestions....
I checked what was happening under cold conditions...by removing the outlet pipe where it attaches itself to the rad bottom hose.....I can also then sit it at the top of the radiator so any water coming out goes directly back into the radiator...therefore no spillage.
Water was 'flowing' when valve open, stopped when closed. .all good. I then decided that there might be an air lock somewhere down in the matrix or the pipes leading to/from. So...with the aid of a funnel, I disconnected the bypass hose, topped it up manually with coolant until it all flowed through and out the other end. Once complete, reattached all hoses and tested.
Bob's your uncle.....once a bit of heat got going, I could actually feel the heater working!

Thnx for your help.