Heater and EWP

[Richard G]

Having just replaced my heater matrix, the heater is now ineffective. I have an Electric Water Pump, EvansCraig, fitted down where Alternator was. Have heard that can give rise to heater not working, still need it these chilly evenings.

Any ideas?

RG

[KOY 23]

2 options, either plumb in a small pump into your heater circuit, you can get one from a scrap Merc, or reroute the heater return / bypass into the pump inlet. I had a custom hose made with T piece.

im puzzled cos you must have had this problem before changing your matrix.

[Richard G]

2 options, either plumb in a small pump into your heater circuit, you can get one from a scrap Merc, or reroute the heater return / bypass into the pump inlet. I had a custom hose made with T piece.

im puzzled cos you must have had this problem before changing your matrix.

Thanks for info, I will try a secondary pump as you suggest. Didn't have the problem before because I bypassed the heater because I cream crackered the valve trying to remove it, it was solid, in closed position!

[Stagsongas]

Having just replaced my heater matrix, the heater is now ineffective. I have an Electric Water Pump, EvansCraig, fitted down where Alternator was. Have heard that can give rise to heater not working, still need it these chilly evenings.

Any ideas?

RG

Richard,

I have a very similar EEWP installation to yours. I got the Heater working perfectly without using an auxiliary pump as my aim was to keep things as simple as possible.

My solution was to the re-plumb the heater return to go down to a bottom hose manifold I made up, so the returned coolant is attracted there by the lower pressure at the back (inlet) of the EEWP. In that way you get proper heater circulation. Aslo, if you haven't done it already, it is far better to have the matrix supply hose going in at the bottom of the matrix and the return coming out of the top connection, it makes the system so much easier to bleed, particularly the matrix itself.

I can't quite recall if I had to fit a flow restrictor in that return path but I could check that for your tomorrow.

On my car I can fully fill and bleed the cooling system clear of all air right from empty without even running the engine, just the pump.

Regards

Steve

[flying farmer]

I have an electric pump on my V8 Toledo using the electronic controller, and the heater is pretty ineffective on that compared to the Stag with the electric pump and constant electric supply using dropped voltage through a resistor.
This is simply because the pump only runs for 10 seconds in every 30 at its set temperature so the heater doesn't get full flow.

If there is a cheap heater pump available from a scrap Mercedes that might be the best option.

Neil

[Stagsongas]

For whatever reason, my heater is toasting hot for 100% of the time it's turned on. That seems to go against the EEWP not running continuously.

Looking back though, I did find quite a significant thermal current in the cooling system when first running the engine without a thermostat fitted (that's still the case). It's only conjecture but maybe that figures somewhere.

Regards

Steve