is my 3 port motorised valve faulty

[AndyPRK]

I have 240 between when probe white and brown wire with dvm. When i move the lever hard to turn heating on voltage drops to 0 between the two

White and orange you mean?

That makes sense. Lever Full over, both live and no potential difference between the wires hence 0v


Have you ordered a motor or head yet?

The other thing to do (with power off at first ) is take the lid off and then remove the circular metal cap off motor.
Then power the system up. The motor should then spin.

 

[ptek2004]

Lol white and blue 0 when heating on and 240 when off when lever is wedged. If not wedged then 0 orange and blue is 240v when wedged over and heatin off. 0 volts when heating on

 

[AndyPRK]

Do I replace motor which looks easy or the whole head as its an old unit

Either. Whatever is cheapest or you are confident with.

 

[AndyPRK]

There are some used heads on eBay which maybe good for a stop gap.

Search for

honeywell 3 port valve head

 

[ptek2004]

Thank you for all the replys. Today I purchased a new syncronous motor for £11.24 fitted and yaaày everything working as it should.

 

[ericmark]

I had exactly the same with my daughters and it was the V3 switch inside the motor head. However could not find a V3 switch in a hurry so bought whole valve and just changed the head.

Not saying other faults could not cause the same but after removal tested micro switch and it was the micro switch which had failed.

 

[ptek2004]

For some reason i checked everything including switch and left motor until last. Was only when i removed the cap applied 240 to it and it was dead. Im a happy bunny saved a fortune too as the wife was going to call an engineer

 

[AlanE]

Just a word of warning regarding replacing Honeywell motorised valve heads.

BEFORE removing old head, well before ordering really, make sure the cover has a 'pimple' on the side away from the actual valve. No 'pimple' means you will get wet if you remove the head!

You can get modification kits to update the old style valves but the system MUST be drained down past level of the valve, but they are not always easy to obtain so really no 'pimple' replace complete valve.