motorised valve issue

[smithandrew12]

Hi all we have a Honeywell 3 Port Mid Position Valve V4073A 1039 which is heating the rads when hot water is on .....when powered down the valve rests in the w position and there is resistance over the last 2 thirds when moving the manual lever when i power up again with hot water only calling the valve goes straight over to the mid point and the moter can be heard clicking with the valve moving minutely left then right ..if i select heating only the valve moves over to the h position but the motor seems to struggle . but it gets there ..my first thought was the motor is knackered or very close to being but could it be the microswitches ..when powered back down the valve rests again in the w position.

 

[D_Hailsham]

The valve could also be sticking.

See How a mid-position valve works

 

[smithandrew12]

cheers ..have had a quick look at the link will look more indepth tomorrow ...the fact that the valve rests in the h postion does travel to the w postion then travels to the midpoint but wont then go back to the h position when only calling for water but then does go to the h postion when powered down does that not mean the full range of travel is achieved

 

[MeldrewsMate]

Struggled to read that, running out of breath at times. Any chance you could put commas or full stops in to make my life easier?

MM

 

[smithandrew12]

Just had another look,when the hot water is turned on the valve goes straight to mid point.Turn water off central heating on valve goes to h turn heating off valve stays in h postion as it should,the problem is why is the valve going straight to mid point when water only turned on.

 

[D_Hailsham]

Just had another look,when the hot water is turned on the valve goes straight to mid point.Turn water off central heating on valve goes to h turn heating off valve stays in h postion as it should,the problem is why is the valve going straight to mid point when water only turned on.

So 240V is getting onto the valve white wire all the time. This comes from the Programmer CH ON terminal via the CH thermostat.

Check voltage on white with the CH ON and room stat on minimum (should be 0V) then with it on max (should be 240V). If CH is OFF it should always be 0V.

 

[smithandrew12]

Now i dont have a multimeter but there is power to the white all the time,using only a circuit tester screwdriver .

 

[D_Hailsham]

Now i dont have a multimeter but there is power to the white all the time,using only a circuit tester screwdriver .

Do the tests in the link I gave. You don't need a meter.