3 port valve

[Matt0029]

How can you tell if it's just the motor that has gone on a 3 port valve?

 

[Last Plumber]

Test the resistance through the winding.
Or
When the motor has live and neutral connected it should be turning. Don't just check live.
Start by testing the winding in ohms.

 

[Matt0029]

Can you install a unbranded motor or does it need to be the Honeywell one? A big price difference

 

[Deleted member 120897]

You fit either, but I’ve heard the cheaper ones don’t last as long. Probably best getting one I believe to be similar in quality, think they’re approx £20?

 

[Last Plumber]

Can you install a unbranded motor or does it need to be the Honeywell one? A big price difference

As undertrained said, There are cheap ones but they will not last as long. The last cheap one I bought from Corgi direct via this forum and it was very noisy. I think you are better sticking to Danfos or similar even though they are more expensive.

 

[Matt0029]

Test the resistance through the winding.
Or
When the motor has live and neutral connected it should be turning. Don't just check live.
Start by testing the winding in ohms.

You can see the actual motor turning?

 

[Matt0029]

If just replacing the head not the motor or full valve I find it earlier to use these for the wiring instead of going on to the box. Do others?

 

[Last Plumber]

You can see the actual motor turning?

You can normally see the valve opening but if not, you could remove the motor.
More often than not there is no reading through the winding or the gears are seizing up and making it difficult for the motor to turn. It is obvious if the motor is at fault.

In answer to your question below, no, if I replace the motor I use the connections that come with it and there are a few options but if I replace the valve or head (very rarely replace the head only to be honest), I just connect in to what's there already and test it.

 

[Matt0029]

Can I ask why you very rarely change the head only?

 

[Matt0029]

So you take a resistant reading through the motor?

 

[Last Plumber]

Can I ask why you very rarely change the head only?

I rarely do that because there is rarely anything wrong with the head, it is normally the motor which has failed and the cost of a head only isn't far off a full valve. I think if it's in a condition where the head needs replacing, the valve is probably in the same condition. This is only based on my experience of course. Other folk will do things differently. There is no right or wrong way of doing it.

They read around 1.9 kilohms. (kilo ohms), or there and there abouts. If they have a failed winding (winding broke) they don't read anything as there is no continuity. As I mentioned previously, sometimes they seize or start to and they aren't powerful enough to make the valve open to the micro-switch but you can tell by moving the manual lever that the resistance is stronger than it should be.

 

[Deleted member 120897]

I rarely do that because there is rarely anything wrong with the head, it is normally the motor which has failed and the cost of a head only isn't far off a full valve. I think if it's in a condition where the head needs replacing, the valve is probably in the same condition.

Do you replace microswitches as well, or is this new head time?

 

[Last Plumber]

Do you replace microswitches as well, or is this new head time?

No I wouldn't.
The valve and motors are in stock (van) so I would decide valve or motor and crack on. I wouldn't get involved with anything else. The aim is to be professional and cost effective with no call back/return work. Do the best job you can and do it once. If there is any suspicion it could be something other than a simple motor replacement, then replace the valve.

Again, this is only my view on things. It is based on my own experience.