Electric water pump and potential heater issues?

Sounds like an interesting project; I'm sure there'll be any number of kids on Arduino forums to help with the code. Just a shame that the supplied controller doesn't do what it's meant to.

Yes, very frustrating. A quick Google indicates this is a very common issue- Davies Craig flog the customer off with "refit the thermostat and drill a 6mm hole in it".

I did some investigating and the microcontroller used in the Davies Craig EWP Controller is this one : http://www.atmel.com...ges/doc2466.pdf (an ATMega16)

I did think about trying to read the program off it, but there's a software lock function that's probably enabled and it's a surface mount device (so hard to desolder and remove.)

Hi guys,

Sorry to drag this thread form the depths but it's the closest to addressing my EWP problems in ALOT of searching! I've created an account so that hopefully someone can help me with it.

I've fitted the EWP80 and controller into a Land Rover Freelander with the 1.8 rover K series engine (notorious for head gasket failure) in an attempt to prevent another HGF. The EWP+cont seems to work on on the main circuit, it always runs colder than the target temp no matter what I do though and I get sweet FA in the way of steady heat through the cabon blowers. Here's a brief breakdown of how me and a mate have fitted ot and modded the old system:

- Changed mech water pump and removed pump vanes.

- Installed the EWP on the lower radiator hose and removed
thermostat/bypass (the hose now goes straight form the rad to teh rail via the EWP.)

- Installed the controller's temp sensor on the upper rad hose close to the outlet.

- Coolant was getting backed up in the expansion tank so we re-routed the tank feed hose to just before the pump and blanded the junction on the coolant rail where it was initially connected. That solved that.

- The heater matrix was being pressurized on both ends due to the new pump location so we re-routed the return hose onto the expansion tank feed hose via a T connector. We reckon that's equalized the pressure.

- Still very little warm air theough the heater so we itted a flow restrictor infront of the rad inlet with a 15mm aperture, messed with the temp it was all over the place so we removed it.

So where the heck do we go next? Any ideas?

Here's a diagram of the modded circuit and of the original one, hope it helps .





Thanks guys I hope someone can help, DC have done what they can but I'm starting to think they haven't tested the system in a wide variety of cars :(.

Will.

Oh dear, apologies for the terrible typo's in that post! I typed it in a rush, this thing has got me at my wits end!

Hi guys,

Sorry to drag this thread form the depths but it's the closest to addressing my EWP problems in ALOT of searching! I've created an account so that hopefully someone can help me with it.

I've fitted the EWP80 and controller into a Land Rover Freelander with the 1.8 rover K series engine (notorious for head gasket failure) in an attempt to prevent another HGF. The EWP+cont seems to work on on the main circuit, it always runs colder than the target temp no matter what I do though and I get sweet FA in the way of steady heat through the cabon blowers. Here's a brief breakdown of how me and a mate have fitted ot and modded the old system:

- Changed mech water pump and removed pump vanes.

- Installed the EWP on the lower radiator hose and removed
thermostat/bypass (the hose now goes straight form the rad to teh rail via the EWP.)

- Installed the controller's temp sensor on the upper rad hose close to the outlet.

- Coolant was getting backed up in the expansion tank so we re-routed the tank feed hose to just before the pump and blanded the junction on the coolant rail where it was initially connected. That solved that.

- The heater matrix was being pressurized on both ends due to the new pump location so we re-routed the return hose onto the expansion tank feed hose via a T connector. We reckon that's equalized the pressure.

- Still very little warm air theough the heater so we itted a flow restrictor infront of the rad inlet with a 15mm aperture, messed with the temp it was all over the place so we removed it.

So where the heck do we go next? Any ideas?

Here's a diagram of the modded circuit and of the original one, hope it helps .

Thanks guys I hope someone can help, DC have done what they can but I'm starting to think they haven't tested the system in a wide variety of cars :(.

Will.

I'm not familiar with these engines so I'm possibly barking up the wrong tree here (BTW are these the ones with the bolts that extend from the main caps thru the block to the head?)...

Looking at this logically, the system was working before the pump was changed and the thermostat/bypass assembly was changed. I doubt the engine would care what kind of pump was moving the water, but I suspect that the thermo/bypass might be more important than it appears to be, and that proper flow through the heater core may depend on this being present. Is it possible to refit the thermo/bypass and plumb everything back to original, with the exception of the new pump?

I'm not familiar with these engines so I'm possibly barking up the wrong tree here (BTW are these the ones with the bolts that extend from the main caps thru the block to the head?)...

Looking at this logically, the system was working before the pump was changed and the thermostat/bypass assembly was changed. I doubt the engine would care what kind of pump was moving the water, but I suspect that the thermo/bypass might be more important than it appears to be, and that proper flow through the heater core may depend on this being present. Is it possible to refit the thermo/bypass and plumb everything back to original, with the exception of the new pump?

Yes it's one avenue I'm prusuing. However having swapped a few emails with DC they are sending me a new sensor as they think mine might be faulty which I aggree with. I've now found that the heater works fine as long as the EWP isn't pulsing - so a small booster pump would solve that. The trouble is that my dodgy sensor is causing the EWP to pulse far more than it should. I set the target to 75 degrees today and even though I know its more like 85-90 in reality the whole system works much better now !

Just in case someone arrives here like I did while looking for info I did manage to fix it. The controller's temperature sensor was way out of calibration - measuring about 25 degrees c below actual temperature. We used two 20k ohm resistors wired in parallel to calibrate it to within a few degrees of actual temperature. It now works flawlessly and the heater is fine. The target is set to 80 and the actual temperature holds steady at about 84 which is perfect for my engine. As long as you heater inlet is downstream of the pump and your outlet is upstream you should be fine, at least that work on my rover K series engine. An infrared thermometer is essential to get accurate temperature readings so that you can calibrate your sensor.

I hope that helps someone .

Will.