Motorised 2 port valve; what has slowed it?

[MeldrewsMate]

It may point to an alternative solution in slightly tightening the return spring tension to eliminate any "resonant" interaction.
Not that I'm going to do that in my current setup, but if the similar valve for CH demand starts tripping an E991 in a similar manner, I may try a bit of spring tweaking before swapping the motor head/replacing the whole unit.

Have you tried the easy and reversible option of lowering the pump pressure head yet? A simple tweak of the pump setting to a slightly lower value may adjust any resonance effect sufficiently to make the fault go away, and at the very least it could eliminate the resonance theory if the problem doesn't go away.
I assume that you meant fault E911, the same as in your first post?

 

[windbagUK]

Have you tried the easy and reversible option of lowering the pump pressure head yet? A simple tweak of the pump setting to a slightly lower value may adjust any resonance effect sufficiently to make the fault go away, and at the very least it could eliminate the resonance theory if the problem doesn't go away.
I assume that you meant fault E911, the same as in your first post?

No, as I had no idea that could, in theory, change the situation for the better.
Now the replacement is in, scope to investigate that has been removed... unless it happens again !
If it does, I will, but, it looked like the pump needed to be at full tilt to give sufficient flow, and since the E911 is labelled as "insufficient flow" by Samsung, any reduction did not seem a sensible avenue to investigate at that time. (Yes, I meant E911).

 

[MeldrewsMate]

You have missed the point; we are considering a resonant vibration of the flow sensor and/or its reed switch. If the Samsung software just happens to read the switch output during the millisecond that its output goes low on each resonant vibration then it could interpret that as a low flow fault E911. The flow may be well in excess of that required to operate the switch under smooth flowing conditions.
Clearly the chance to definitively reproduce the fault has been lost with the valve change, however lowering the pump head, even temporarily, to the point at which a TRUE low flowrate alarm is triggered will give confidence that the full pump head is comfortably above that needed for adequate flow.

 

[DP]

I can well believe the new valve is faster. But that is the point.
WHY is it faster - or - WHY has the old one become slower ?
On the old one, there is no visible sign of wear on the ball.
I can see no obvious degradation of the old unit at all.

The ball plate through which the spindle passes, has two O rings on the spindle. Over time these add resistance to angular movement to finally at some point negate pull of the spring such that with valve shut, port may stay open partially as springs cannot fully shut the valve, or valve will spindle may be too stiff for the motor to open the Valve. I sometimes wonder if Honeywell valves made now are inferior to valve of yesteryears that gave years of faultless operation

lift The ball plate off the brass body, you can dismantle the spindle and check. Spot of silicon on the O rings, I suspect the issue will be resolved.

Daresay one needs a timer to time the events for comparison as visual/ audio senses not accurate enough

 

[DP]

I can well believe the new valve is faster. But that is the point.
WHY is it faster - or - WHY has the old one become slower ?
On the old one, there is no visible sign of wear on the ball.
I can see no obvious degradation of the old unit at all.

The ball plate through which the spindle passes, has two O rings on the spindle. Over time these add resistance to angular movement to finally at some point negate pull of the spring such that with valve shut, port may stay open partially as springs cannot fully shut the valve, or valve will spindle may be too stiff for the motor to open the Valve. I sometimes wonder if Honeywell valves made now are inferior to valve of yesteryears that gave years of faultless

lift The ball plate off the brass body, you can dismantle the spindle and check. Spot of silicon on the O rings, I suspect the issue will be resolved.

Daresay one needs a timer to time the events for comparison as visual/ audio senses not accurate enough

 

[windbagUK]

The ball plate through which the spindle passes, has two O rings on the spindle. Over time these add resistance to angular movement to finally at some point negate pull of the spring such that with valve shut, port may stay open partially as springs cannot fully shut the valve, or valve will spindle may be too stiff for the motor to open the Valve.

As detailed in the posts, this is not the case. The valve opens as fast as the new one and is easily actionable by finger.

lift The ball plate off the brass body, you can dismantle the spindle and check. Spot of silicon on the O rings, I suspect the issue will be resolved.

Cannot try as now swapped out

Daresay one needs a timer to time the events for comparison as visual/ audio senses not accurate enough

I have done timings - which are the main basis for this query - as the OLD one is, if anything, faster than the new one.

 

[windbagUK]

You have missed the point; we are considering a resonant vibration of the flow sensor and/or its reed switch. If the Samsung software just happens to read the switch output during the millisecond that its output goes low on each resonant vibration then it could interpret that as a low flow fault E911.

The likelihood of what you describe is so low on the probability scale that it becomes chasing after a situation that Samsung would be artificially creating by software timings coinciding with the notional resonance of an aging valve. And just as likely to occur on a new valve, which I've not seen reported anywhere. If this were the case, then after further aging, the timing could "slow" more, the "resonance" go out of phase and the valve would once again become deemed "fast enough". This way madness lies.

The flow may be well in excess of that required to operate the switch under smooth flowing conditions.
Clearly the chance to definitively reproduce the fault has been lost with the valve change, however lowering the pump head, even temporarily, to the point at which a TRUE low flowrate alarm is triggered will give confidence that the full pump head is comfortably above that needed for adequate flow.

It becomes unwieldly when the fact that the it only occurs when the DHW is called for (adjustments upstairs) and any adjustments to the pump have to be actioned downstairs. At this level of likelihood, plus work to verify, I lose the will to live...

 

[Johntheo5]

If this is a widespread problem surely Samsung can programme a 5 sec delay or whatever.

 

[Nozzle]

The reasons I'm puzzled is that the main opposition to the motor turning are the built-in springs (the main activation lever is very easy to turn)
But springs don't get stronger with age - if anything the opposite.
Or the motor torque has dropped - but why, when it remains totally clean, dust free, main rotor spins freely on the bearings ?

Or friction has increased - the valve gland packing or sludge or corrosion product

Nozzle

 

[DP]

Or friction has increased - the valve gland packing or sludge or corrosion product

Nozzle

That is what I said.

If poster wants to bring the valve to glasgow, have electronic timer, will time the exact duration . By timer interval do not mean a stop watch

Question asked was what slows the valve. My reply was the angular movement of the spindle which gets stiffer ( over time) to move due to O rings malfunction and loss of grease on the spindle.

 

[Madrab]

wow, has this really got to 4 pages long

 

[Justin Passing]

I haven't read every post.
Did it occur to anyone to temporarily wire a switch in place of the supposed slow-operating one, stand there for however long it takes closing it at different delays to see if it's a problem?
WOUld save a load of guessing.

And yes those motors do slow with age, despite there being no theoretical reason in someone's opinion. If theory and practice don't agree, the theory is incomplete.

 

[Harry Bloomfield]

And yes those motors do slow with age, despite there being no theoretical reason in someone's opinion. If theory and practice don't agree, the theory is incomplete.

They cannot slow, they are a synchronous motor - they either run to speed, or stall.

 

[DP]

I haven't read every post.
Did it occur to anyone to temporarily wire a switch in place of the supposed slow-operating one, stand there for however long it takes closing it at different delays to see if it's a problem?
WOUld save a load of guessing.

And yes those motors do slow with age, despite there being no theoretical reason in someone's opinion. If theory and practice don't agree, the theory is incomplete.

They cannot slow, they are a synchronous motor - they either run to speed, or stall.

The poster says the valve taken out is faster than one that has taken its place unless I am misreading.

Have many times encountered valves that are slow to operate and same for releasing. On occasion the gearbox can be gubbed, mostly the spindle seizes

 

[windbagUK]

The poster says the valve taken out is faster than one that has taken its place unless I am misreading.

Correct.