Potterton EP2002 and Myson MPE222 valve problem..

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Does the motor on the 2 port valve continue to operate even when the valve is fully open and it can travel no further. I ask this because I have disassembled my 2 port valve to investigate why occasionally the boiler does not get a call to heat the water and noticed that even if I tape the microswitch on the valve in the closed position the motor on it continues to run. Is this normal to keep the valve open and prevent the spring returning it to the closed position.

I was thinking that the controller is on the blink but now I not so sure...

If I turn up the room thermostat the boiler operates as normal..?

 

[D_Hailsham]

Does the motor on the 2 port valve continue to operate even when the valve is fully open and it can travel no further.

Yes. The synchronous motor is designed to do this. If the motor stopped, the valve would automatically close under the influence of the spring.

even if I tape the microswitch on the valve in the closed position the motor on it continues to run.

The microswitch (grey and orange wires)is completely separate from the motor (brown and grey wires). When the valve is closed the microswitch is open and vice-versa.

The valve motor is controlled from the programmer Heating ON terminal via the room thermostat.

If I turn up the room thermostat the boiler operates as normal..?

That's how it's supposed to work

If the room is below the temperature set on the room stat: the room stat closes - motorised valve opens - microswitch closes - boiler runs.

When the room reaches temperature the opposite happens: room stat opens etc etc.

So what is your problem exactly?

 

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Thanks for the response....
My problem is ;

light on 2 port valve for cylinder is on, motor operating and valve is fully open. There is an intermittant problem of the boiler not getting any call to heat the water. Currently, after turning mains power off then on it is now working. This is 3rd day though that this probelm has occured.

During this phase of no call to heat I turned up the room thermostat and the boiler fired up. I was trying to rule out an issue with the boiler.

I have given the microswitch a spray with acf50 to ensure its not sticking and I can here it click on/off.
I was wondering if the controller was playing up?

 

[D_Hailsham]

Do you have a multimeter?

 

[onwards]

Sorry, been out all day...
I do have a multimeter......

 

[D_Hailsham]

I do have a multimeter......

and know how to use it?

Does the cable from the motorized valve go into a separate junction box or into the EP2000?

If it's a separate junction box do the following:

Turn power off and remove box lid
Set programmer to HW and CH OFF
Set room stat and HW stat to MIN
Turn power ON

1. Measure voltage between valve Brown and Blue - should be 0Vac
2. Measure voltage between valve Grey and Blue - should be 240Vac
3. Measure voltage between valve Orange and Blue - should be 0Vac

Now turn HW ON and repeat the checks 1-3 above. The results should be the same.

Now turn the HW stat to max (boiler should light) and repeat the tests.

You should get:

1. Brown-Blue: 240Vac
2. Grey - Blue: 240Vac
3. Orange Blue: 240Vac

If (1) is still 0Vac, the cylinder thermostat or the HW channel of the programmer is faulty.

If (2) and (3) are not both 240Vac the valve is faulty. Either it is not opening or the microswitch is not closing.

You can check if the valve opens as follows:

With everything turned off, move the valve lever in the slot from Auto to Man. You should feel resistance when you move it and it should return to the Auto end when you let go.

Now turn system on, call for HW and check the lever again.

This time it should move from Auto to Man very easily - it should feel floppy.

 

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I'll have a look at that and post back later...
Many Thanks....

 

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I'm currently waiting for it to go wrong again before I do the tests.
Having sprayed the microswitch and the moving parts of the valve with ACF-50 wondering if it was a sticking switch, time will tell..

 

[D_Hailsham]

I'm currently waiting for it to go wrong again before I do the tests.

I hope you are charging yourself for waiting time.

Having sprayed the microswitch and the moving parts of the valve with ACF-50 wondering if it was a sticking switch, time will tell..

Post back to this topic with the results.

 

[onwards]

I'm currently waiting for it to go wrong again before I do the tests.

I hope you are charging yourself for waiting time.

Having sprayed the microswitch and the moving parts of the valve with ACF-50 wondering if it was a sticking switch, time will tell..

Post back to this topic with the results.

I sent my missus the bill but she told me to F off

I'm still waiting for this to break again... Maybe it was a sticky switch. The ACF-50 seems to have cured it.....

I'll post back if it goes wrong again....
Thanks again...