faulty mid position actuator or blown fuse?

[newdiy]

my 3-port mid position actuator seems to have developed a fault. it only responds automatically to hot water calls but not heating calls. I have to manually push the lever from W to H position to trigger boiler to get heating.

The model numbe is BGMVSP-23. I have learnt from plumbing forum that it is British GAS branded.

I am not sure what has gone wrong, so any advice would be appreciated.

happy easter.

 

[seco services]

maybe a faulty room stat or motor inside the actuator.
would say the motor first, check for power across motor when calling for heat.

 

[newdiy]

thanks seco.

the heating light on the timer is on when the room stat clicks to call for heating. but the actuator still does not switch itself from W to H to get heating. It only goes one way from H to W to get hot water.

I have a digital multimeter from maplin. what should I check for?

 

[seco services]

remove the lid on the actuator their is two wires to the motor.
get the system calling for heat and see if you have power to the motor.

 

[newdiy]

ok. I have one of this multimeter

http://www.doctronics.co.uk/images/meter2.gif

which position do I need to turn the central knob to check for power.

 

[seco services]

put the programmer on constant calling for heating and wall stat up to max and check for voltage/power at the motor

 

[newdiy]

yes, I open the cover and see five wire: grey, orange, blue, white and earth. which two wires do I connect the multimeter probes to ?

is it correct that I the meter knob points to upper right dial marked V 200?

 

[seco services]

forget the five wires on the main cable their should be two thin orange wires on the motor with connectors to the circuit board.

 

[newdiy]

thank you.

the voltage reading is 50 or 94 between the two orange wires, does this sound correct ?

 

[seco services]

should be 230 v when activated

 

[newdiy]

http://leegate.f2s.com/mid.jpg

As you can see in the picture, I measured it between the two orange wires, from left to right, the 1st wire and the 3rd wire.

Black probe to 1st and red to 3rd , the reading is 50v
Red probe to 1st and black to 3rd, the reading is 94 v.

I have a reading out of wall socket, the reading is 247 v, which indicate my meter is not accurate enough. even so, the 90v is too low .

could this mean the wrong voltage to the motor?

 

[seco services]

no thats ok.
find your wiring centre white box where all your wires meet and with just the programmer on heating and wall stat up to max tell me what reading you have on the white wire. (theirs only one white)

 

[newdiy]

it's 247. the same as my wall plug. (i connect one DMM probe to earth and one to the white wire)

 

[seco services]

when you turn wall stat down you should have no voltage at white.

 

[newdiy]

that's right. no voltage. (the timer is still on)

there is no voltage between two orange wires either.