Three Way Valve

[John]

Mate has removed motor - should he be able to rotate the valve mechanism quite easily?

[The Natural Philosopher]

yes. If not use plumbers wrench or moles to free it up. If it doesnt free up you need a new body as well as the motor

[Fredxx]

The motor might well be fine, though purchasing a complete valve body/motor generally makes economic sense.

[Harry Bloomfield, Esq.]

John has brought this to us :

Yes, the D should be almost able to be turned with your bare fingers. Be aware that some valve are only designed to be rotated in one direction - the motor turns them through a full 360 degrees to get to the position needed. The other version only rotates back and forth through 180 deg.

[Harry Bloomfield, Esq.]

It happens that Fredxx formulated :

Them failing in some way, became almost an annual task here of the spring return variety. In 40 years I have only had two motors fail, more often its microswitch, or plastic body/ rotor jamming failures. I have since changed to a type of 3 port valve which doesn't use a spring, rather it rotates in just one direction to position.

The design seems much more sensible and under much less mechanical stress and so likely to have a much longer service life. None the less, I have a spare valve head in a box next to it, ready to pop on - just in case.

[John]

The Natural Philosopher [e-mail] wrote in news:r7un9g$h5s$2 @dont-email.me:

Approx how many degrees each side of centre should it turn? Drayton

[T i m]

Rotate, as in 360 Degrees? No. Rotate a few degrees either way and with your fingers, yes (or the one I last played with you could).

Imagine that inside there is a hard rubber ball on a short stick connected to the spindle. Basically you can only move the ball between the two internal openings of the two outlets (where the rubber ball seals them off).

Cheers, T i m

[The Natural Philosopher]

My 'one ways' are 90 deg. I guess a three way is 180 in all. Someone else knows better

[Fredxx]

A Drayton one I changed recently moved ~20 degrees. This used a disc of rubber to cover and uncover ports.

[Harry Bloomfield, Esq.]

John submitted this idea :

They can normally spun all the way round.

[Harry Bloomfield, Esq.]

Harry Bloomfield, Esq. was thinking very hard :

Just the lose valve spindle that is, the head will turn it maybe 110 degrees or so.

[Harry Bloomfield, Esq.]

Fredxx presented the following explanation :

Is that a 2-port, or a 3-port?

[Fredxx]

3-port

[Chris B]

This was exactly how mine worked. Total shaft movement not more than 20 or 30 degs.

Here is an image of the insides

[Chris B]

Indeed you may find some useful info towards the bottom of the page that picture comes from

[Fredxx]

This gives a (poor) diagram of wedged shaped piece of rubber that prides a flat surface to seal each port. This 'wedge' is on an arm and perhaps the detail of the wedge indicates the lack of movement for all three positions (assuming a mid-position valve).

[Clive Page]

What brand is that? Not in need of a replacement yet, but agree that don't last all that long.

[Harry Bloomfield, Esq.]

The general type is called a MOMO actuator - Motor On, Motor Off. I was so fed up with the spring return design of 3-port actuator failing, I had decided I ought to attempt a design of my own, then I came across the Sunvic 1901 MoMo valve and actuator.

It was electrically a rather clever design, which was a direct electrical swap for my spring return Sunvic valve, but I had to swap the valve and actuator over to the 1901 as a pair. Old valve is designed to work back and forth, through limited degrees. 1901 valve is designed to rotate only clockwise to position.

It's one flaw, seems to be it is susceptible to water damage, unless mounted actuator uppermost. Because it may have turn the valve through almost 360 degrees to position, it can take it an extra minute to fire the boiler on a change in demand, but it consumes almost no current to maintaining position. None the less, I keep a spare 1901 actuator ready to just fit.

This site is worth a read -

[tabbypurr]

Yup. If it won't move you'll need a new baseplate or body, depending on how yours is put together.

NT

[T i m]

I believe the spindle on the Honeywell 3-Way valves is sealed with an 'O' ring and retained by a clip so could be stripped, cleaned and lubed (silicone grease?).

I've done that sort of thing loads of times, just to get something fixed 'for now' and it's still been working years later.

Cheers, T i m