WHP Catalyst wonky recirc valve

[DADoES]

 
The recirc/drain valve seems to not always release at end of a cycle.  Remains energized into the next cycle and thus drains the water if a catalyst treatment is involved and throws an F4 fault.  Only way to reset the valve is pull the power cord.

I can make the issue occur for sure by running a spin-only, press pause, restart it ... if then canceled (press pause twice), OR at end of the spin, the valve does not release.  If a spin-only is started and canceled (without a pause & restart first), the valve does release.  A weird software bug?

I'm running a full cycle to normal completion now to check what happens.

Is failure of the drain valve to release (unless/until the power cord is disconnected) an indication of a bad valve, or a problem with the control board?  The board sends power to the valve, the valve doesn't internally generate its power, right?

 

[DADoES]

 
Also, the bleach tray doesn't drain fully.  If a cycle is run with no bleach, the tray fills with water from the flush input and doesn't drain at all.  I don't find any clogging in the dispenser, the hose(s), or the output nozzle on the tub ring.

 

[DADoES]

 
Confirmed.  The drain valve does not de-energize at end of a cycle until the power cord is disconnected.  Reconnecting the power does not immediately re-energize the valve, it stays off until the next cycle drains.

What???

 

[repair-man]

I have experienced the recirculate valves stick in the drain position. Of course a new valve solved the problem.

 

[DADoES]

 
Doesn't seem it's physically sticking.  If that was the case, disconnecting the power cord without otherwise touching the machine wouldn't release the valve.  It releases immediately when the plug is pulled.  Consistent coincidence?

 

[repair-man]

Been a number of years since I saw this but I remember something was strange about it. There may be a minimal amount of current allowed through the circuit even when the control board is not energizing a certain component. I think it was enough that the bad valve (either a weak return spring or too much return resistance) would hold in position after the board cuts power. Although I would think all power would cut out at the end of the cycle. It's easy to check. Make it stick with the cabinet off and see how easy it is to manually push the valve back to it's neutral position. If the board is erroneously energizing the solenoid you will not be able to. If it's just sticking then you can easily move it.

 

[DADoES]

 
Thanks for the tip.  Does seem that sticking is the cause.  I would never have figured the valve to have a low current-flow when the machine otherwise is off.

 

[kb0nes]

It's also possible output device that does the switching on the control board is doing something funky.

If its a solid state Triac it could just be remaining in a conducting mode even after it shouldn't. Perhaps even partially allowing enough current to flow to keep the valve open as Ed mentioned.

I'd attempt to trace the wire to the controller connector then trace back on the PCB to find the switching device. Then you should be able to determine what they use for switching. It could be a Triac, a solid state relay or a mechanical relay. It may be easy to swap that part to effect a repair. If you can determine the device on the board you think is doing the switching post any markings on the device or a photo.

Most control board failures are due to either power supply issues or the output switching device failing and are reasonably easily repairable. I have salvaged a few furnace boards by simply swapping a common component.

 

[DADoES]

 
I ordered a replacement valve (overnight shipping, it's an urgent situation), but I'm thinking again that the valve is not the problem.

It has a strong release spring, and does not stick when I manually press and hold it into actuated position.  Springs back immediately and strongly when I let go of it.

Info gathered elsewhere says the valve is DC-powered, has an onboard rectifier.  But that wouldn't be the direct source of "holding" current, it has to come from the control board.

I have no experience tracing/troubleshooting electronic boards.

 

[DADoES]

 
No way to access the electrical components, it's sealed.

 

[DADoES]

 
White/red wire, 2nd from the left on this connector if I didn't munge the trace.

 

[DADoES]

 

 

[DADoES]

 

 

[kb0nes]

My suspicion is that the valve coil is being driven by one of those six white 6-legged IC's. You'd have to follow the trace on the backside of the board from the pin on the connector to figure which device it is.

My guess is that the IC's are Triac output optical couplers. Its quite possible that the one that drives that relay has become "leaky".

Could you read the part ID on one of those IC's and share it? Also is there an identifying part number on the PC board itself??

 

[DADoES]

 
No way I can see the numbers but my spiffy camera can. 

There are two kinds.

Lower three presumably are all the same ...

 

[DADoES]

 
Upper three ...

 

[DADoES]

 
And this tag on the corner of the board.

 

[kb0nes]

Motorola MOC3023

Indeed the IC's are a opto isolators that have a small Triac output device designed to isolate and drive a larger Triac. Its a bit unconventional to use these to directly switch a load, although it could be done if the current draw was fairly small.

Pins 1 & 2 are for an internal infrared LED which will optically turn on the output Triac when ~3v is applied across the LED. Pins 4 & 6 are essentially the AC "switch" that will turn on a current path to drive your valve relay.

I don't know if you are comfortable with measuring voltages on the IC's or not but if you were you should see the LED drive voltage drop off when the valve isn't energized and the output AC voltage _should_ drop off at the same point. A failure of the device could make it leak. DigiKey sells the IC's for $.68 each, but you'd have to be comfortable with reworking the board.

Not sure any of this helps but its more information for possible understanding

 

[DADoES]

 
Put it this way ... I did several small Heathkit projects years ago, am game to try.  Problem is this machine goes in one of my neighbor's rental properties.  New people move in Sat so he wants it back before then.  They have a washer but he doesn't want them to move it in for fear they'd be satisfied it could stay and he'd have this machine to store somewhere ... and possibly the matching dryer if they'd want to move theirs in as well.  It is usable other than the valve sticking, which comes into play only on cycles that use the Catalyst treatment, so I suppose fixing this is not mandatory, perhaps a project at the next renter turnover.

This week has been a huge ruckus on multiple fronts.